Beating Drug Tests and Defending Positive Results
Amitava Dasgupta
Beating Drug Tests and Defending Positive Results A Toxicologist’s Perspective
Amitava Dasgupta Department of Pathology and Laboratory Medicine University of Texas Health Science Center at Houston Medical School 6431 Fannin Houston TX 77030 Room 2258 USA
[email protected] ISBN 978-1-60761-526-2 e-ISBN 978-1-60761-527-9 DOI 10.1007/978-1-60761-527-9 Springer New York Dordrecht Heidelberg London Library of Congress Control Number: 2009943300 © Springer Science+Business Media, LLC 2010 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Humana Press, c/o Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed on acid-free paper Humana Press is part of Springer Science+Business Media (www.springer.com)
Preface
Workplace drug testing was initiated by President Ronald Reagan when he issued Executive Order Number 12564 requiring federal agencies to drug test federal employees who are involved in sensitive positions as well as positions involving public safety. In today’s business practice, a majority of the Fortune 500 Companies implement some practice of workplace drug testing in their company policies. Workplace drug testing deters employees from abusing drugs. A drug free workplace can lead to increased productivity, less job related accidents as well as improved morale in the workplace. Unfortunately, drug abusers also need employment and often try to beat pre-employment drug testing by ingesting a variety of substances available through the Internet or by adding various adulterants in vitro after collecting the urine specimen. Although ingesting various substances along with drinking plenty of water has some effectiveness in producing negative results, identification of low creatinine in a urine specimen submitted for drug testing is an indication of such an attempt and the toxicology laboratory may not perform the drug testing at all on that specimen and reported the specimen as adulterated. Similarly, adding household chemicals to a urine specimen can be easily identified by using specimen integrity testing (temperature, pH, specific gravity, and creatinine concentration) prior to drug analysis. However, more recently, chemicals can be obtained through Internet sites which, when added to urine specimens cannot be detected by routine specimen integrity testing. Some of these chemicals are also effective in oxidizing the drug and or its metabolite, thus causing false negative test results not only in the immunoassay screening step but also in the gas chromatography/mass spectrometric confirmation test. The test which is most affected is the testing of marijuana as the marijuana metabolite 11-nor-9-carboxy−COOH). Fortunately, spot tests and various other 9 -tetrahydrocannabinol (THC− tests are available to detect the presence of such adulterants (nitrites, pyridinium chlorochromate, glutaraldehyde, peroxidase, etc.). There is a constant battle between toxicologist and underground chemists who produce such adulterants. Fortunately, many states now ban the use of such adulterants in order to invalidate a drug test. Moreover, toxicologists are winning this battle because of the dedicated efforts of many investigators to stay one step ahead of these cheats. As a practicing toxicologist, I am involved with the pre-employment drug testing of our hospital and I wrote this book covering all major issues concerning v
vi
Preface
how people try to beat drug tests and defend positive test results, using my experience with pre-employment drug testing in our hospital. In each chapter, an extensive number of references are cited so that more interested readers can get more information on a particular topic that interests them. I hope this book will be helpful to toxicologists, medical technologists, pathologists, human resources professionals, and anyone who is interested in workplace drug testing. Houston, Texas
Amitava Dasgupta
Acknowledgments
I would like to thank Ms. Alice Wells, MT (ASCP) for critically reading and editing the entire manuscript. I also thank Professor Robert Hunter, MD, PhD, chair of our department for his support to undertake this project. I also thank American Association for Clinical Chemistry, the publisher of the Clinical Chemistry Journal, for granting permission to reprint copyrighted material for this book free of charge. I would like to thank my wife for her support during the long hours at night and at weekends I spent on this project. Proper credits are given in the references or in the text for all original sources of information including all United States Government sources where the information is in the public domain. I have made sincere efforts to list all such references and credits. If, after all these efforts, there is any omission of a source or reference brought to my attention, I will be glad to include any such omission in the subsequent reprint of this book.
vii
Contents
1 Beating Drug Tests and Defending Positive Results: A General Overview . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . 2 Commonly Abused Drugs in the United States . . . 3 Workplace Drug Testing . . . . . . . . . . . . . . 4 How People Try to Beat Drug Tests? . . . . . . . . 5 How People Defend Positive Results? . . . . . . . 6 Designer Drugs/Rave Party Drugs and Workplace Drug Testing . . . . . . . . . . . . . . . . . . . . . 6.1 Detection of Designer/Rave Party Drugs . . . 7 Conclusions . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
1 1 2 3 3 5
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
6 8 8 9
2 Pharmacology of Commonly Abused Drugs . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 Amphetamine, Methamphetamine and Related Drugs . . . 2.1 Metabolism of Amphetamine and Methamphetamine 2.2 Designer Drugs Derived from Amphetamines . . . . 2.3 Metabolism of Designer Drugs Derived from Amphetamines . . . . . . . . . . . . . . . . . . 2.4 Overdoses and Fatalities from Amphetamines and Related Drugs . . . . . . . . . . . . . . . . . . . 3 Barbiturates . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Metabolism and Fatality from Barbiturates . . . . . . 4 Benzodiazepines . . . . . . . . . . . . . . . . . . . . . . 4.1 Pharmacology of Benzodiazepines . . . . . . . . . . 4.2 Benzodiazepine Overdose and Fatality . . . . . . . . 5 Cannabinoids . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Metabolism of THC . . . . . . . . . . . . . . . . . . 5.2 THC Overdose . . . . . . . . . . . . . . . . . . . . 6 Cocaine . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Pharmacology of Cocaine . . . . . . . . . . . . . . . 6.2 Abuse of Cocaine and Alcohol . . . . . . . . . . . . 6.3 Fatality from Cocaine and Cocaethylene . . . . . . .
. . . . .
. . . . .
. . . . .
11 11 11 12 12
. . .
14
. . . . . . . . . . . . .
15 15 16 17 17 18 19 19 20 20 21 22 22
. . . . . . . . . . . . .
. . . . . . . . . . . . .
ix
x
Contents
7
Opiates . . . . . . . . . . . . . . 7.1 Pharmacology of Opiates . . 8 Methadone . . . . . . . . . . . . . 8.1 Pharmacology of Methadone 9 Phencyclidine . . . . . . . . . . . 10 Propoxyphene . . . . . . . . . . . 11 Methaqualone . . . . . . . . . . . 12 Glutethimide . . . . . . . . . . . 13 Conclusions . . . . . . . . . . . . References . . . . . . . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
22 23 24 24 24 25 26 26 26 27
3 Workplace Drug Testing: SAMHSA and Non-SAMHSA Drugs 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 2 SAMHSA Mandated Drugs . . . . . . . . . . . . . . . . . . 3 Testing of Various SAMHSA Mandated Drugs . . . . . . . . 3.1 Testing of Amphetamines . . . . . . . . . . . . . . . . 3.2 Testing of Cannabinoid (Marijuana) . . . . . . . . . . 3.3 Testing of Cocaine Metabolites . . . . . . . . . . . . . 3.4 Testing of Opiates . . . . . . . . . . . . . . . . . . . . 3.5 Testing of Phencyclidine . . . . . . . . . . . . . . . . 4 Testing of Non-SAMHSA Drugs . . . . . . . . . . . . . . . 4.1 Testing of Barbiturates . . . . . . . . . . . . . . . . . 4.2 Testing of Benzodiazepines . . . . . . . . . . . . . . . 4.3 Testing of Methadone . . . . . . . . . . . . . . . . . . 4.4 Testing of Propoxyphene . . . . . . . . . . . . . . . . 4.5 Testing of Methaqualone and Glutethimide . . . . . . . 5 Miscellaneous Issues in Workplace Drug Testing . . . . . . 6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
29 29 30 31 32 33 34 36 37 38 38 40 40 41 41 42 42 43
4 Synthetic Urine, Flushing, Detoxifying, and Related Agents for Beating Urine Drug Tests: Are They Effective? 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 Synthetic Urine . . . . . . . . . . . . . . . . . . . . . . 3 Composition of Synthetic Urine . . . . . . . . . . . . . 4 Specimen Integrity Testing . . . . . . . . . . . . . . . . 5 Prosthetic Penis and Workplace Drug Testing . . . . . . 5.1 Catheterization for Substituting Urine . . . . . . . 6 Flushing and Detoxifying Products . . . . . . . . . . . . 6.1 Water Intoxication . . . . . . . . . . . . . . . . . . 6.2 Diluted Urine and Drug Testing . . . . . . . . . . . 6.3 SAMHSA Criteria for Diluted/Substituted Urine . . 6.4 Diluted Urine: Case Studies . . . . . . . . . . . . . 6.5 Do These Agents Work? . . . . . . . . . . . . . . 7 Herbals to Beat Drug Tests . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
45 45 46 47 47 48 49 50 51 51 53 54 55 56
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
Contents
xi
8
Various Drugs and False Negative/Positive Screening Assay Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Household Chemicals and Internet Based Products for Beating Urine Drug Tests . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Household Chemicals as Urinary Adulterants . . . . . . . . . 2.1 Effect of Various Adulterants on Immunoassay Screening 2.2 Effect of Various Household Adulterants on Specimen Integrity Testing . . . . . . . . . . . . . . 3 Internet Based Urinary Adulterants . . . . . . . . . . . . . . . 3.1 Adulteration Product Urine Luck . . . . . . . . . . . . . 3.2 Adulteration Products Containing Nitrite . . . . . . . . . 3.3 Adulteration with Glutaraldehyde Containing Products . 3.4 Stealth as a Urinary Adulterant . . . . . . . . . . . . . . 3.5 Papain as Urinary Adulterant . . . . . . . . . . . . . . . 4 Detection of Internet Based Adulterants . . . . . . . . . . . . 4.1 Testing for Urine Luck . . . . . . . . . . . . . . . . . . 4.2 Testing for Nitrite . . . . . . . . . . . . . . . . . . . . . 4.3 Testing for Stealth . . . . . . . . . . . . . . . . . . . . . 4.4 Testing for Glutaraldehyde . . . . . . . . . . . . . . . . 4.5 Onsite Adulteration Check and Automated Assays . . . . 5 Federal Guidelines for Additional Testing to Detect Adulterants . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 A Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57 58 58
. . . .
61 61 62 63
. . . . . . . . . . . . .
65 67 67 68 69 70 71 71 71 72 73 73 73
. . . .
75 75 76 76
. . . . . . . . . . . .
79 79 80 81 81 83 84 85 86 86 87 87
7 Defending Positive Opiate and Marijuana Test Results . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . .
89 89
6 Adulterating Hair, Oral Fluid, and Sweat Specimens for Drug Testing . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 Hair Drug Testing . . . . . . . . . . . . . . . . . . . . . . 2.1 Hair Color and Incorporation of Drugs . . . . . . . . 2.2 Environmental Contamination and Hair Drug Testing 2.3 Adulteration of Hair Specimens . . . . . . . . . . . . 3 Oral Fluid Testing for Abused Drugs . . . . . . . . . . . . 3.1 Adulteration of Oral Fluid . . . . . . . . . . . . . . 4 Sweat Testing . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Adulteration Issues . . . . . . . . . . . . . . . . . . 5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . .
xii
Contents
2
Poppy Seeds and Opium . . . . . . . . . . . . . . . 2.1 Opium Content of Various Poppy Seeds . . . . 2.2 Poppy Seed and Allergy . . . . . . . . . . . . . 2.3 Opiate Level After Consumption of Poppy Tea (Opium Tea) . . . . . . . . . . . . . . . . . . . 2.4 Consumption of Poppy Seed Containing Food and Urinary Opiates . . . . . . . . . . . . . . . 2.5 Consumption of Poppy Seed Containing Food and Opiate Levels in Other Matrix . . . . . . . 2.6 Consumption of Poppy Seed Containing Food and Impairment . . . . . . . . . . . . . . . . . 2.7 Brown Mixture and Opiate Levels . . . . . . . 2.8 Legal Consequence of Positive Opiate Due to Ingestion of Poppy Seed Containing Food . . . 3 Marker for Poppy Seed Consumption in Urine . . . . 4 Defending Positive Marijuana Results . . . . . . . . 4.1 Passive Inhalation of Marijuana . . . . . . . . . 4.2 Consumption of Hemp Products . . . . . . . . 5 Case Study . . . . . . . . . . . . . . . . . . . . . . 6 Conclusions . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
90 90 91
. . . . . .
91
. . . . . .
92
. . . . . .
94
. . . . . . . . . . . .
95 95
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
95 96 97 97 97 99 99 100
8 Defending Positive Cocaine Tests . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . 2 Herbal Tea and Cocaine . . . . . . . . . . . . . . . . . 2.1 Coca Tea and Urinary Level of Benzoylecgonine 2.2 Legal Consequence of Positive Cocaine Due to Ingestion of Coca Tea . . . . . . . . . . . . . 3 Mugwort and Positive Cocaine . . . . . . . . . . . . . 4 Procaine and Workplace Drug Testing . . . . . . . . . 5 Benzocaine, Tetracaine, Lidocaine, and Workplace Drug Testing . . . . . . . . . . . . . . . . . . . . . . . 6 Paper Money Contaminated with Cocaine . . . . . . . 6.1 Handling Money Contaminated with Cocaine and Drug Testing . . . . . . . . . . . . . . . . . 7 Passive Inhalation/Exposure of Cocaine . . . . . . . . 8 Case Studies . . . . . . . . . . . . . . . . . . . . . . . 9 Conclusions . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . .
. . . .
. . . .
. . . .
. . . .
103 103 104 105
. . . . . . . . . . . . . . .
106 107 107
. . . . . . . . . .
108 109
. . . . .
. . . . .
110 111 112 112 113
. . . . . .
115 115
. . . . . . . . .
116 117 119
. . . . .
9 Defending Positive Amphetamine Results . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 OTC and Prescription Drugs that Produce False Positives with Amphetamine/Methamphetamine Immunoassays . . . R Inhaler and Positive Methamphetamine Test 3 Use of Vicks 4 Herbal Weight Loss Products and Amphetamine Assay . .
. . . . .
. . . . .
Contents
5 6
Bitter Orange and Amphetamine Immunoassay . . . . . . False Positive GC/MS Methamphetamine Due to Ephedrine or Pseudoephedrine . . . . . . . . . . . 7 False Positive Amphetamine Due to Prescription Drug Mebeverine . . . . . . . . . . . . . . . . . . . . . . . . . 8 Analytical True Positive Amphetamine/Methamphetamine 9 Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . 10 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xiii
. . .
120
. . .
121
. . . . .
. . . . .
122 125 126 127 127
. . . . .
131 131 132 134 135
. . . . . . .
136 137 138 138 139 139 140
Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
143
. . . . .
10 Analytical True Positives in Workplace Drugs Testings Due to Use of Prescription and OTC Medications . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Prescription Medications Containing Benzodiazepines . . . . . 3 Topical Use of Cocaine and Workplace Drug Testing . . . . . 4 Prescription Opiates and Workplace Drug Testing . . . . . . . 4.1 Detection of Hydromorphone After Medical Use of Morphine . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Detection of Hydrocodone After Medical Use of Codeine 5 OTC Opiates and Workplace Drug Testing . . . . . . . . . . . 6 Marinol and Workplace Drug Testing . . . . . . . . . . . . . . 6.1 Marijuana and Chocolate . . . . . . . . . . . . . . . . . 7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1
Beating Drug Tests and Defending Positive Results: A General Overview
Abstract Drug abuse is a psychological problem and approximately 20 million Americans abuse drugs. A person abusing drugs also needs a job. People try to beat drug tests in various ways from substituting someone else’s urine for their own, drinking flushing and detoxifying agents and adding adulterants to the urine specimen after collection. In vitro urinary adulterants can be common household chemicals or Internet based chemicals such as “Urine Aid,” “Urine Luck” and “Klear.” When tested positive a person may come up with many excuses such as taking prescription medication, drinking herbal tea, and passively inhaling marijuana. Professionals involved in workplace drug testing should be familiar with the various ways in which people try to beat drug test and defend positive results. Keywords Adulteration · Beating drug test · Invalidate tests
1 Introduction Searching msn.com with the words “beat drug test” produces an amazing 7,930,000 web sites as the search result. Google search with the same key words produced 49,200,000 sites within 0.20 s. Alcohol and drug abuse is a serious public health issue worldwide. In one report published in 1999, an estimated 60 million Americans smoke, 14 million people were abusing alcohol and another 14 million people were taking illicit drugs. As a result, 590,000 deaths, about 25% of all deaths in the United States, were caused by addictive substances, 105,000 from alcohol abuse, 446,000 from tobacco use and 39,000 from addictive drugs in 1995. In addition, such addictions cause 40 million illnesses and injuries each year and the economic burden of such abuse is estimated to be over $400 billion including health care costs, low worker’s productivity and crime. Drugs and alcohol abuse are risk factors for crime, family violence, accidents, birth defects, divorce and disability [1]. In 2006, an estimated 20.4 million Americans (8.3% of the population) aged 12 or older used illicit drugs. Marijuana was the most common illicit drug abused
A. Dasgupta, Beating Drug Tests and Defending Positive Results, C Springer Science+Business Media, LLC 2010 DOI 10.1007/978-1-60761-527-9_1,
1
2
1
Beating Drug Tests and Defending Positive Results
(14.8 million people) in the year 2006, while 2.4 million people abused cocaine, 528,000 people abused ecstasy and 731,000 people abused methamphetamine. In addition, 7.0 million people took prescription medication non-medically and among them 5.2 million people abused pain relievers where no medical condition existed for taking such medication [2]. In 2007, an estimated 19.9 million Americans aged 12 or older used illicit drugs, showing a slight decline from the 2006 statistics.
2 Commonly Abused Drugs in the United States Commonly abused drugs in the United States include amphetamine, methamphetamine, cocaine, morphine, codeine, heroin, various benzodiazepines and barbiturates. In addition, several synthetic opiates such as oxycodone, hydrocodone, oxymorphone, hydromorphone and meperidine and fentanyl are also abused. The less frequently encountered agents are magic mushrooms (containing mescaline), peyote cactus (psilocybin) and various designer drugs. Solvent abuse is common among teenagers but less common in the adult population. In addition, abuse of various herbal products such as Jimson weed, and chewing of leaves (Kath abuse) are also encountered among people abusing drugs. All agents with high abuse potential are treated as controlled substances in the United States and their use is regulated by the Federal Drug Administration of the United States. In most parts of the world, drugs of abuse and related substances with high abuse potential are controlled by the Government. The Drug Abuse Control Act of 1956 provided guidelines for pharmaceutical industries for manufacturing and dispensing controlled substances. In 1970, the Controlled Substances Act was passed in order to find a balance between regulating drugs which have medical benefits but at the same time to prohibit improper import, manufacture, distribution and possession of controlled substances. The major focus of this law was the scheduling of drugs into five different classes based on abuse potential, harmfulness and development of drug dependence as well as potential benefits when used medically Several amendments were later added to the Controlled Substances Act of 1970. Controlled substances are categorized in five groups depending on the medical need and abuse potential. Schedule I: The drug has a high abuse potential and no known medical use. Example of a Schedule I drug is heroin. Schedule II: The drug has a currently accepted medical use but also has a high abuse potential and use may lead to drug dependency. Example of a Schedule II drugs is cocaine. Schedule III: The drug has a currently accepted medical use but also has an abuse potential which is less than drugs of Schedule I and II. Abuse of the drug may cause moderate to low dependency. Example of Schedule III drugs are anabolic steroids. Schedule IV: The drug has current medical use and but also has a low potential for abuse relative to Schedule I, II and III drugs. Abuse of the drug may cause limited
4
How People Try to Beat Drug Tests?
3
dependency relative to drugs classified in Schedule III. Example of a Schedule IV drug is diazepam Schedule V: The drug has a current medical use and also has a low potential for abuse compared to drugs in Schedule IV. Abuse of the drug may lead to limited dependency relative to Schedule IV drugs. Example of a Schedule V drug is cough mixture containing low level of codeine. Most designer drugs are now included in the list of controlled substances and possession of such drugs without proper license is a criminal act.
3 Workplace Drug Testing On September 15, 1986, President Reagan issued Executive Order No 12564 directing federal agencies to achieve a drug free work environment. Then the Department of Health and Human Services (DHHS, Formerly NIDA) developed guidelines and protocols for drugs of abuse testing. The mandatory guidelines for Federal Workplace Drug Testing Program were first published in the Federal Register on April 11, 1988 (53 FR 11970), and have since been revised in the Federal Register on June 9, 1994 (59 FR 29908) and also on September 30, 1997 (62 FR 51118). Another notice was issued on April 13, 2004 (Federal Register, Vol 69, No 71). The overall testing process under mandatory testing consists of proper collection of specimen, initiation of chain of custody and finally analysis of specimen (screening and GC/MS confirmation if needed) by a SAMHSA (Substance Abuse and Mental Health Services Administration, an agency under Department of Health and Human Services on the United States Government) certified laboratory. The screening by immunoassay should be performed using an FDA (Food and Drug Administration of the United States) approved method. The confirmation should be performed by a second technique, preferably by gas chromatography/mass spectrometry (GC/MS). It is estimated that approximately 20 million employees are screened each year in the United States for illicit drugs. The drug testing programs in the US can be either mandatory or non-mandatory. In the first category (for example, the Department of Transportation) a regulated employer is required by federal regulation to test the employees. In the second category, employers choose to test for reasons other than the federal requirements. Private employers who are not mandated to test under federal authority have instituted employee drug testing in order to create a drug free workplace. These programs also formalized the role of a specialist physician termed as MRO (Medical Review Officer).
4 How People Try to Beat Drug Tests? In general there are several ways people try to beat drug tests. Synthetic and drug free human urine is readily available in the clandestine market and when urine collection is not watched, a person undergoing workplace drug testing can substitute synthetic or drug free urine for his or her specimen. Various detoxifying agents are
4
1
Beating Drug Tests and Defending Positive Results
available through the Internet and the manufacturers of these products claim that these agents are effective in flushing out drugs from the body. Certain adulterants should be added in vitro to pass a drug test. Drug testing laboratories routinely perform “Specimen Integrity Testing” on each specimen submitted for workplace drug testing. These tests include creatinine, specific gravity, temperature and pH of the specimen. All values should be within acceptable limits in order for the specimen to be processed further for workplace drug testing. Substituting one’s urine with drug free urine is a sure way to pass the drug test unless the laboratory testing such a specimen can identify it as a substituted specimen due to its unacceptable temperature. Urine temperature should be between 32 and 38 ◦ C and the temperature of a substituted specimen may fail outside that range because of failure to maintain the proper temperature outside the body. Many flushing and detoxifying agents lead to production of diluted urine and creatinine may fall outside the acceptable range. Please see Chap. 4 for a more in-depth discussion of this topic. People also add various household chemicals to urine in vitro in order to invalidate workplace drug testing. Early report of use of household chemicals as urinary adulterants appeared in 1988. Milkkelsen and Ash reported the effect of eight adulterants (sodium chloride, Visine eye drops, hand soap, Drano, bleach, vinegar, golden seal tea and lemon juice) on immunoassay screening step for drugs of abuse testing [3]. Later, many Internet based companies started selling in vitro adulterants in order to beat workplace drug testing. These in vitro adulterants are strong oxidizing agents such as potassium nitrite and pyridinium chlorochromate. In addition, glutaraldehyde and a combination of peroxidase enzyme and hydrogen peroxide (Stealth) are also available for beating drug tests [4–8]. These adulterants cannot be detected by routine specimen integrity testings (pH, creatinine, specific gravity and temperature) and special spot tests or dipstick based tests are required to identify such adulterants in urine specimens. Addition of pyridinium chlorochromate changes the natural color of urine to very dark yellow, but such color may also been seen in the urine specimen of a dehydrated person or a person taking vitamin B complex or riboflavin. See Chap. 5 for details. See Table 1.1 for different ways people try to beat drug test. Federal guidelines defined an adulterated specimen as a urine specimen containing a substance that is not a normal constituent or containing an endogenous substance at a concentration that is not a normal physiological concentration. In the military where the urine collection process is supervised, the chances of receiving adulterated specimens are reduced, but in pre-employment screening, where direct supervision of specimen collection is not practiced, a person may attempt to escape detection of drugs of abuse by adulterating specimens to avoid unwanted consequences of failing a drug test. Several precautions are taken by the personnel of the collection site to avoid such adulteration of submitted specimens such as asking the donor to remove outer garments (coat or jacket) that may contain concealed adulterating substances. The collector should ensure that all personal belongings such as a purse or a briefcase stay with the collector.
5
How People Defend Positive Results?
5
Table 1.1 Various ways people try to beat drug tests Beating drug test
Effect on drug tests
Substituted urine
May be hard to identify by the specimen integrity test. A person may pass drug test Diluted urine which may be flagged by the specimen integrity testing. Concentration of drug/metabolite may be lower Similar effects as detoxifying agents These chemicals can be easily detected by the specimen integrity testing except Visine eye drops. If not flagged by the specimen integrity testing, these specimens may produce false negative results by various immunoassay screening methods. Should be detected by special specimen integrity tests, otherwise may cause false negative results Should be detected by special specimen integrity tests, otherwise may cause false negative results Should be detected by special specimen integrity tests, otherwise may cause false negative results Should be detected by special specimen integrity tests, otherwise may cause false negative results
Detoxifying agents
Flushing agents Adding household chemicals to the urine
Adding nitrite containing adulterants Adding PCCa adulterant Adding glutaraldehyde containing adulterants Stealth adulterant a PCC:
Pyridinium chlorochromate
When a donor is unable to provide a urine specimen, the donor may have intentionally urinated prior to arriving at the collection site, has a physical disability making it impossible to provide a specimen, or has a “shy bladder.” The term “shy bladder” usually refers to an individual who is unable to provide a specimen either upon demand or when someone is nearby during the attempted urination. If a donor tells the collector, upon arrival at the collection site, that he or she cannot provide a specimen, the collector must unwrap or open a collection container and request the donor to try to provide a specimen. If that fails, the donor is given a reasonable amount of fluid to drink distributed reasonably through a period of up to 3 h, or until the donor has provided a new sufficient amount of urine, whichever occurs first. If the donor refuses to drink fluids as directed or refuses to attempt to provide a urine specimen, the collection procedure is discontinued and deemed a “refusal to test.”
5 How People Defend Positive Results? When a person tests positive in a workplace drug testing, he or she has the right to see the Medical Review Officer (MRO) of the company to explain the positive drug testing result. Although, taking certain prescription medication may cause a positive result in workplace drug testing, upon producing appropriate documentation, the MRO has the authority to determine the drug testing as negative because the positive test result is consistent with the documented prescription. See Chap. 10 for details.
6
1
Beating Drug Tests and Defending Positive Results
Table 1.2 Various ways people defend positive results Drug tested positive
Common excuse
Amphetamines
Taking over-the-counter cold medication Using Vicks inhaler Taking herbal weight loss products Taking over-the-counter sleeping aid Dentist used procaine Handled contaminated paper money Eating poppy seed containing food Taking pain medication Passive inhalation of marijuana in a party Drinking hemp oil
Benzodiazepines Cocaine Opiates Marijuana
However, a workplace drug testing can also be positive if the person being tested is abusing drugs. People come up with many excuses for positive test results including taking poppy seed cake containing food, passive inhalation of marijuana, drinking hemp oil, herbal tea and a variety of other health food products. See Chaps. 7, 8, 9 and 10 for more detail. Various ways people defend positive results are summarized in Table 1.2. The way people try to beat drug tests and defend positive results are also reviewed in the literature [9].
6 Designer Drugs/Rave Party Drugs and Workplace Drug Testing Designer drugs are not routinely tested for in workplace drug testing and a person taking such drugs may pass a workplace drug test. Major rave party drugs are designer drugs derived from amphetamine and methamphetamine such as 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy), and 3,4-methylenedioxy-amphetamine (MDA) as well as ketamine, gamma hydroxy butyrate (GHB) and other drugs. After 1986, a large number of amphetamine analogs were synthesized by clandestine laboratories to produce more potent effects after abuse. The common examples of these designer drugs include para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 2,5-dimethoxy-4methylamphetamine (DOM), 2,5-dimethoxy-4-methylthio-amphetamine (DOT), 4-iodo-2,5-dimethoxyamphetamine (DOI), 2,5-dimethoxy-4-bromo-amphetamine (DOB), 2,5-dimethoxy-4-bromo-methamphetamine (MDOB), N-methyl-1-(3,4)(methylenedioxy-phenyl)-2-butanamine (MBDB) and 3,4-(methylenedioxyphenyl)-2-butanamine (BDB). In addition, a chlorinated analog of MDMA has been detected in the urine of a drug abuser [10]. Bossong et al. also described two new ecstasy-like substances: methylone (3,4-methylenedioxymethcathinone) and mCPPP (meta-chlorophenylpiperazine). Methylone is the main ingredient of liquid designer drugs that appeared in the underground Dutch market [11]. Designer
6
Designer Drugs/Rave Party Drugs and Workplace Drug Testing
7
drugs such as PMA, PMMA and 4-methylthioamphetamine (4-MTA) have also been encountered at rave parties. 4-MTA is usually sold as “ecstasy” or “flatliners” on the illegal drug market. MDMA, MDA, PMA and related designer drugs are also widely used in rave parties along with ketamine and other drugs. Like amphetamine and methamphetamine, these designer drugs are also very toxic and deaths have been reported from abusing these drugs. The designer drug which is an analog of fentanyl appeared in the underground market of California in 1979 and was sold as “China White.” The active ingredient of China White is α-methylfentanyl, a very potent analog of fentanyl. Abuse of China White caused over 100 deaths in California. Gillespie et al. determined postmortem blood, bile and liver concentrations of α-methylfentanyl in a drug overdose victim. The blood concentration of α-methylfentanyl was 3.1 ng/mL, bile concentration was 6.4 ng/mL while the level in liver was 78 ng/g of liver tissue [12]. In 1984, another illicit designer drug, 3-methylfentanyl, appeared as a street drug in California which was also related to fatal drug overdose. During 1988, 3-methylfentanyl was identified in 16 fatal overdose cases in Allegheny County in Pennsylvania. In addition to 3-methylfentanyl, morphine was detected in the blood of five individuals and cocaine was detected in the blood of three persons [13]. Gamma hydroxy butyrate (GHB) is an endogenous constituent of mammalian brain which is a metabolite of gamma-hydroxy butyric acid (GHBA). GHB is present in nanomolar concentration in the brain and acts as a neurotransmitter. Until 1990 it was sold in health food stores as a food supplement and became popular among athletes as an alternative to steroids because it was believed that GHB helped an individual to build muscle mass without any exercise. Sixteen cases of adverse effects due to GHB containing health products were reported to the San Francisco Bay Area Regional Poison Control Center from June to October 1990. Use of GHB caused coma in four patients and tonic-clonic seizure in two patients for dosage ranging from one quarter of a teaspoon to four tablespoons [14]. Because reports of adverse effects due to use of GHB, the FDA banned the over-the-counter sale of GHB in November 1990. Currently (as of March 2000), GHB is a Schedule I controlled substance in the US. A 25 mg/kg oral dose caused dizziness in adult subjects with an average plasma concentration of 80 μg/mL. Blood GHB concentration over 260 μg/mL caused deep sleep, levels of 156–260 μg/mL caused moderate sleep and levels of 52–156 μg/mL caused light sleep [15]. In one report the concentrations of GHB in blood of eight patients who died from GHB overdose ranged from 77 mg/L to 370 mg/L [16]. In another report the femoral blood and urinary concentrations of GHB in a fatal overdose were 2,937 mg/L and 33,727 mg/L respectively. These values seem to be the highest reported concentrations of GHB in fatal overdoses [17]. Because GHB is cleared from both blood and urine relatively rapidly compared to other drugs, testing of hair specimens is useful to document exposure of a victim to GHB during sexual assault. Kintz et al. also documented the presence of GHB in hair after a single exposure and demonstrated that hair analysis is useful to document use of GHB during a sexual assault [18]. Rohypnol (flunitrazepam) is a benzodiazepine which is not currently available in the US although it is used medically in Europe and other parts of the world.
8
1
Beating Drug Tests and Defending Positive Results
Flunitrazepam can cause rapid sedation and is used in date rape situations. A single 1- or 2-mg dose of flunitrazepam can produce a significant sedative effect and this drug is more potent than diazepam. This drug is used along with GHB in rave parties and date rapes. In addition, ketamine, a dissociative anesthetic (the person taking it feels detached from the environment) which is structurally and pharmacologically related to phencyclidine, is also abused in rave parties. Ketamine can produce similar hallucinogenic effects as phencyclidine. Ketamine is a Schedule II drug with limited use in medicine but is used more often in veterinary medicine. Ketamine abusers use this drug intravenously and the effect can be felt immediately. Ketamine comes in a clear liquid or whitish powder. The liquid can be injected while the powder can be dissolved and injected or can be taken orally or intranasally. Ketamine is also habit forming and severe overdose can even cause death.
6.1 Detection of Designer/Rave Party Drugs Although MDMA and MDA can be determined in human urine by using specific immunoassay for detecting ecstasy or even amphetamine screening assay, gas chromatography/mass spectrometry (GC/MS) confirmation can easily confirm these drugs and differentiate them from amphetamine; not all amphetamine immunoassays are suitable for detection other designer drugs such as PMA, PMMA, MDEA, and especially not for the new piperazine-derived substances [19, 20]. Although there are various chromatographic techniques for determining these drugs in human urine and other body fluids, there is a possibility that a person may pass a workplace drug testing taking such drugs because if the initial immunoassay screen is negative usually chromatographic confirmation test is not performed. Similarly, there is no currently available immunoassay to determine fentanyl analogs or GHB. Therefore, GHB cannot be detected by routine drugs of abuse testing protocol. In the case of suspected overdose of GHB, a more sophisticated analytical technique such as GC/MS should be employed for determination of GHB concentrations in blood or urine. GHB in blood can be determined using GC/MS after liquid-liquid extraction and disilyl-derivatization [21].
7 Conclusions Although people try to beat drug tests in many innovative ways, there are various ways of catching these people. Routine specimen integrity testing and special testings for chromate, nitrate and oxidizing agents will identify most of these cheats. Many states have passed laws where an attempt to cheat a drug test is considered a felony or misdemeanor. Although current practice is not full proof to catch all cheaters, it is very unlikely that a drug abuser will pass a workplace drug test by
References
9
cheating. The ways people try to defend a positive test results are mostly ineffective and in the majority of cases ineffective to defend positive test results in a court of law.
References 1. McGinnis JM, Foege WH. Mortality and morbidity attributable to use of addictive substances in the United States. Proc Assoc Am Physicians 1999; 111:109–118 2. US Department of Health and Human Services: National survey on drug use and health, Washington DC. US Department of Health and Human Services; 2006 (Office of Applied Studies) 3. Milkkelsen SL, Ash KO. Adulterants causing false negatives in illicit drug testing. Clin Chem 1988; 34:2333–2336 4. Paul BD, Martin KK, Maguilo J, Smith ML. Effects of pyridinium chlorochromate adulterant (urine luck) on testing of drugs of abuse and a method for quantitative detection of chromium (VI) in urine. J Anal Toxicol 2000; 24:233–237 5. Dasgupta A, Wahed A, Wells A. Rapid spot tests for detecting the presence of adulterants in urine specimens submitted for drug testing. Am J Clin Pathol 2002; 117:325–329 6. ElSohly MA, Feng S, Kopycki WJ, Murphy TP, Jones AB, Davis A, Carr D. A procedure to overcome interferences caused by adulterant “Klear” in the GC-MS analysis of 11-nor-9THC-9-COOH. J Anal Toxicol 1997; 20:240–242 7. Tsai SC, ElSohly MA, Dubrovsky T, Twarowska B, Towt J, Salamone SJ. Determination of five abused drugs in nitrite-adulterated urine by immunoassay and gas chromatography-mass spectrometry. J Anal Toxicol 1998; 22:474–480 8. Tsai LS, ElSohly MA, Tsai SF, Murphy TO, Twarowska B, Salamone SJ. Investigation of nitrite adulteration on the immunoassay and GC-MS analysis of cannabinoids in urine specimens. J Anal Toxicol 2000; 24:708–714 9. Dasgupta A. The effect of adulterants and selected ingested compounds on drugs of abuse testing in urine. Am J Clin Pathol 2007; 228:491–503 10. Maresove V, Hampl J, Chundela Z, Zrcek F et al. The identification of a chlorinated MDMA. J Anal Toxicol 2005; 29:353–358 11. Bossong MG, Van Dijk JP, Niesink RJ. Methylone and mCPP, two new drugs of abuse. Addict Biol 2005; 10:321–323 12. Gillespie TJ, Gandolfi AUJ, Davis TP, Morano RA. Identification and quantification of alphamethylfentanyl in post mortem specimens. J Anal Toxicol 1982; 6:139–142 13. Hibbs J, Perper J, Winek CL. An outbreak of designer drug-related deaths in Pennsylvania. JAMA 1991; 265:1011–1013 14. Dyer JE. Gamma-hydroxybutyrate: a health food product producing coma and seizure like activity. Am J Emerg Med 1991; 9:321–324 15. Gamma-hydroxybutyrate. In: RC Baselt, RC Cravey. Disposition of Toxic Drugs and Chemicals in Man. Chemical Toxicology Institute, Foster City, CA, 1995, pp 348–349 16. Caldicott DG, Chow FY, Burns BJ, Felgate PD et al. Fatalities associated with the use of gamma-hydroxybutyrate and its analogs in Australia. Med J Aust 2004; 181:310–313 17. Kintz P, Villain M, Pelissier AL, Cirimele V et al. Unusually high concentrations in fatal GHB case. J Anal Toxicol 2005; 29:582–585 18. Kintz P, Cirimele V, Jamey C, Ludes B. Testing for GHB in hair by GC/MS after single exposure. Application to document sexual assault. J Forensic Sci 2003; 48:195–200 19. Lekskulchai V, Mokkhavesa C. Evaluation of Roche Abuscreen ONLINE amphetamine immunoassay for screening of new amphetamine analogues. J Anal Toxicol 2001; 25: 471–475
10
1
Beating Drug Tests and Defending Positive Results
20. Staack RF, Fritschi G, Maurer HH. Studies on the metabolism and the toxicological analysis of the new piperazine-like designer drug N-benzylpiperazine (BZP, A2) using gas chromatography-mass spectrometry (GC-MS). J. Chromatogr. B Analyt Technol Biomed Life Sci 2002; 773:35–46 21. Elian AA. GC-MS determination of gamma-hydroxybutyric acid (GHB) in blood. Forensic Sci Int 2001; 122:43–47
Chapter 2
Pharmacology of Commonly Abused Drugs
Abstract Various drugs are abused and workplace drug testing depending on the half-life of the abused drug tests for the presence of either the abused drug or its metabolites. For example, benzoylecgonine, a major metabolite of cocaine, is tested in workplace drug testing because the half-life of cocaine is approximately 15 min. Understanding the pharmacology of various abused drugs is essential in order to interpret test results in workplace drug testing. In addition to the federal mandate of five drugs, several other abused drugs are often tested for by private employers in workplace drug testing programs. The pharmacology of these abused drugs will be discussed in this chapter. Keywords Amphetamine · Cocaine · Drug abuse · Marijuana · Opiate · Pharmacology
1 Introduction Various drugs are commonly abused including amphetamine, methamphetamine, various benzodiazepines, barbiturates, cocaine, natural and synthetic opiates including methadone, phencyclidine, marijuana, propoxyphene, methaqualone and glutethimide. In addition, various designer drugs such as 3,4-methylenedioxyamphetamine, 3,4-methylene-dioxymethamphetamine and lysergic acid diethylamide (LSD) are also commonly abused. Many abused drugs have a half life and metabolites are often targeted for detection in the urine specimen during workplace drug testing. The pharmacology of abused drugs provides insight into the workplace drug testing.
2 Amphetamine, Methamphetamine and Related Drugs Several stimulants and hallucinogens chemically related to phenylethylamine are referred to collectively as amphetamine-type stimulants. Amphetamines are sympathomimetic amines and are often optically active. In general, the D-enantiomers A. Dasgupta, Beating Drug Tests and Defending Positive Results, C Springer Science+Business Media, LLC 2010 DOI 10.1007/978-1-60761-527-9_2,
11
12
2 Pharmacology of Commonly Abused Drugs
stimulate the central nervous system, while L-enantiomers act peripherally, for example provide appetite suppression. Although amphetamine was used in the past in treating depression, the current use of amphetamine and related compounds are limited to treating narcolepsy, attention deficit disorders, and minimal brain dysfunction. Amphetamines increase synaptic dopamine concentrations, primarily by stimulation of presynaptic release rather than by blockade of reuptake. Increased levels of dopamine in the brain elicit euphoria, contributing to the addictive properties of amphetamines. Amphetamines can be administered orally due to good bioavailability and the protein bindings of amphetamine and methamphetamine are low (less than 20%). Both amphetamine and methamphetamine are controlled substances and are classified as Schedule II drugs.
2.1 Metabolism of Amphetamine and Methamphetamine Hepatic and renal clearance contribute to the elimination of amphetamine and methamphetamine with an elimination half-life between 6 and 12 h. Hepatic metabolism is extensive but a significant part of both drugs is excreted unchanged in urine. Amphetamine and related compounds are weak bases with pKa around 9.9 and they have relatively low molecular weights. Therefore, amphetamine and related compounds can diffuse through cell membranes and lipid layers to tissues and biological matrices which have pH lower than blood. In addition to urine and blood, amphetamine like compounds can also be detected in alternative matrices such as sweat, saliva, hair and nail [1]. A significant portion of both amphetamine and methamphetamine are excreted in the urine unchanged. Amphetamine also undergoes aromatic hydroxylation to parahydroxyamphetamine and oxidative deamination to produce finally benzoic acid [2]. A part of methamphetamine is amphetamine. Major metabolites of amphetamine and methamphetamine are listed in Table 2.1. Chemical structures of amphetamine and methamphetamine are given in Fig. 2.1.
2.2 Designer Drugs Derived from Amphetamines One of the most abused designer drugs which is also an analog of amphetamine is 3,4-methylenedioxymethamphetamine (MDMA, ecstasy). This drug was synthesized by a chemist at Merck in 1914 as an appetite suppressant. Another closely related designer drug, 3,4-methylenedioxyamphetamine(MDA) was synthesized first in 1910. After 1986, a large number of amphetamine analogs were synthesized by clandestine laboratories to produce more potent effects after abuse. These designer drugs include para-methoxy-amphetamine (PMA), paramethoxy-methamphetamine (PMMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 2,5-dimethoxy-4-methylamphetamine (DOM) and 2,5-dimethoxy-4methylthioamphetamine (DOT) [1,2]. Other designer drugs in this class include 4-iodo-2,5-dimethoxyamphetamine (DOI), 2,5-dimethoxy-4-bromo-amphetamine
2
Amphetamine, Methamphetamine and Related Drugs
13
Table 2.1 Major metabolites of drugs of abuse Drug
Major metabolite
Amphetamine Methamphetamine
Unchanged drug Amphetamine
Barbiturates Secobarbital Pentobarbital Amobarbital Phenobarbital
3-Hydroxysecobarbital 3-Hydroxy-pentobarbital 3-Hydroxy-amobarbital p-Hydroxy-phenobarbitala
Benzodiazepine Alprazolam Diazepam Lorazepam Clonazepam Triazolam Cocaine
4-Hydroxy-alprazolam, α-hydroxy-alprazolam Oxazepama , nor-diazepam Conjugated with glucuronic acid 7-Aminoclonazepam 4-Hydroxy-triazolam α-hydroxy-triazolam Benzoylecgonine, Ecgonine Methyl ester, Nor-cocaine
Opiates (Natural and Synthetic) Heroin 6-Monoacetylmorphine, morphinea Codeine Morphine, morphine-3-glucuronide Morphine Morphine-3-glucuronide Hydrocodone Hydromorphone Oxycodone Oxymorphone Methadone 2-Ethylidene-1,5-dimethyl-3,3-diphenyl pyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrrolidine (EMDP) Phencyclidine cis- and trans-1-(1-phenyl-4-hydroxycy-clohexyl)piperidine, Propoxyphene Nor-propoxyphene Tetrahydrocannabinol 11-Nor-9-carboxy-9 -tetrahydrocannabinola (THC-COOH) a Also
excreted in urine as a conjugate of glucuronic acid
(DOB), 2,5-dimethoxy-4-bromo-methamphetamine (MDOB), N-methyl-1- [3,4]methylenedioxy-phenyl)-2-butanamine (MBDB) and 3,4-(methylenedioxyphenyl)2-butanamine (BDB). In addition, a chlorinated analog of MDMA has been detected in the urine of a drug abuser [3]. Bossong et al. also described two new ecstasy like substances; methylone (3,4-methylenedioxymethcathinone) and mCPPP (metachlorophenyl-piperazine). Methylone is the main ingredient of liquid designer drugs that appeared in the underground Dutch market [4]. The designer drugs such as PMA, PMMA and 4-methylthioamphetamine (4-MTA) have also been encountered at rave parties. 4-MTA is also sold as “ecstasy” or “flatliners” on the illegal drug market. Other designer drugs derived from phenylethylamine include 4bromo-2,5-diemthoxy-β-phenylethylamine (2C-B), 2,5-dimethoxy-4ethylthioβ-phenylethylamine (2C-T-2), 2,5-dimethoxy-4 propylthio-β-phenylethylamine (2C-T-7) and related drugs which are also abused. The drugs belonging to 2C series are among the most potent drugs and are selective to serotonin 5-HT2 receptor. These drugs are also toxic and fatality from using 2C-T-7 has been reported. These designer drugs are mainly metabolized in the liver [5].
14
2 Pharmacology of Commonly Abused Drugs CH3
NH2
Amphetamine CH3
NH H3C
Methamphetamine NH2 O
O
CH3
3,4- Methylenedioxymethamphetamine
Fig. 2.1 Chemical structure of amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy)
2.3 Metabolism of Designer Drugs Derived from Amphetamines MDMA is metabolized to 3,4-methylenedioxyamphetamine(MDA) and a variety of other compounds including 4-hydroxy-3-methoxymethamphetamine (major metabolite), 3,4-dihydroxy-methamphetamine and 3-hydroxy-4-methoxymethamphetamine. The majority of 4-hydroxy-3-methoxymethamphetamine is excreted in urine as conjugated with glucuronide or sulfate. Polymorphism of CYP2D6 may partly regulate the O-demethylation pathway of MDMA metabolism and subjects deficient in CYP2D6 (poor metabolizers) may be at higher risk of developing MDMA toxicity. However, in this metabolic pathway, a mechanism based inhibition of enzyme is also encountered due to the formation of an enzymemetabolite complex that affects all subjects regardless of genotype. Therefore
3
Barbiturates
15
impact of CYP2D6 polymorphism on development of acute drug toxicity may be limited [6]. In contrast, CYP2D6 polymorphism plays an important role in the toxicity of the designer drug 4-methylthioamphetamine (4-MTA). The CYP2D6 rapid metabolizers may be at higher risk of developing from abuse of 4-MTA than the respective poor metabolizers [7].
2.4 Overdoses and Fatalities from Amphetamines and Related Drugs Fatal poisoning from amphetamine and methamphetamine has been reported in the literature. In addition, methamphetamine abuse increases the length of hospital stay in minimally injured patients and results in trauma center resource utilization out of proportion to severity of injury [8]. Kojima et al. reported fatal methamphetamine poisoning in a 25-year-old woman who, after self-administration of 50 mg of methamphetamine hydrochloride, intravenously ingested approximately 1.5 g of methamphetamine after 3 h. Hyperpyrexia played an important role in her death with a rectal temperature of above 41◦ C estimated at death [9]. Ecstasy has been encountered in several fatalities in drug abusers. Byard et al. reported several fatalities from ecstasy abuse where hyperthermia (temperatures of 41.5–46.1◦ C) was the cause of three deaths. Other drugs involved in cases of severe toxicity/fatality included amphetamine/methamphetamine and PMA [10].
3 Barbiturates Barbituric acid was first synthesized in 1864 and has no pharmacological activity but barbital derived from barbituric acid has sedative hypnotic property. Over 2,500 derivatives of barbituric acid were synthesized and approximately 50 of them have been marketed. Currently, there are approximately 12 different barbiturates which are used medically worldwide. Barbiturates are central nervous system depressants and are used medically as sedatives, hypnotics, anaesthetics as well as anticonvulsants. Based on the duration of action, barbiturates are classified as ultra short acting, short acting, intermediate acting and long acting barbiturates. Barbiturates can be administered both orally and intravenously. The ultra-short acting barbiturates can produce anesthesia within minutes after intravenous administration. Currently thiopental and methohexital are commonly used drugs in this category. After oral administration, the short and intermediate acting barbiturates such as amobarbital, butalbital, butabarbital, pentobarbital, secobarbital and talbutal produce pharmacological action within 15–40 min and the effect may last up to 6 h. These drugs are used for treating insomnia and may also be used to achieve preoperative sedation. Long acting barbiturates such as phenobarbital and mephobarbital are classified as Schedule IV drugs and are medically used as anticonvulsants and also for day time sedation. The duration of action may last
16
2 Pharmacology of Commonly Abused Drugs
up to 12 h. Usually short and intermediate acting barbiturates are abused and long acting barbiturates such as phenobarbital are rarely abused. Mechanism of action of barbiturates is GABA (gamma-amino butyric acid)-mediated inhibition of synaptic transmission. At low doses, barbiturates acts as modulators of GABA receptors enhancing postsynaptic inhibitory potential by activating chloride ion channel and at higher dosage barbiturates act as GABA agonists. Barbiturates demonstrate anxiolytic effects at a dosage close to producing hypnotic effects and such dosages also affect motor skill and mood. Chronic administration of barbiturates causes dependence. Because of nonselective binding of barbiturates with GABA receptors as well as negative side effects of barbiturates in treating anxiety disorder, these drugs are mostly replaced by benzodiazepines in treating anxiety disorder [11]. Depending on the abuse potential of barbiturates, they are classified either as a Schedule II or a Schedule III drug. Chemical structures of common barbiturates secobarbital, pentobarbital and phenobarbital are given in Fig. 2.2. Fig. 2.2 Chemical structures of secobarbital, pentobarbital, and phenobarbital
O
O HN
H2C
NH
O HCH2C
O CHC3H7 CH3
HN O C2H5
NH O CHC3H7 CH3
Pentobarbital Secobarbital O HN
NH
O C2H5
O
Phenobarbital
3.1 Metabolism and Fatality from Barbiturates Barbiturates are extensively metabolized to a number of different metabolites. Secobarbital is metabolized to 3-hydroxysecobarbital, secodiol and 5-(1methylbutyl) barbituric acid. None of the metabolite has any pharmacological activity. Pentobarbital is metabolized primarily to 3-hydroxypentobarbital which
4
Benzodiazepines
17
is inactive. Another metabolite, N-hydroxypentobarbital, is present in much lower amounts in urine compared to 3-hydroxypentobarbital. A major metabolite of amobarbital is 3-hydroxy-amobarbital, which has some pharmacological potency [12]. Major metabolites of commonly abused barbiturates are given in Table 2.1. Pentobarbital is used in euthanasia of animals by veterinarians. Suicide by injecting veterinarian euthanasia agent containing pentobarbital has been reported [13]. There are other cases of suicide by taking pentobarbital [14]. Tracqui et al. described a fatal intoxication in a person involving secobarbital, nitrazepam and codeine. The blood concentration of secobarbital (11.48 μg/mL) was significantly higher (nitrazepam 1.72 μg/mL and codeine 0.036 μg/mL) than two other drugs and probably was the major cause of death [15].
4 Benzodiazepines Benzodiazepines, as a class of drugs, are most widely prescribed drugs worldwide and are used for treating anxiety, insomnia, anesthetic adjuncts, anticonvulsants, muscle relaxant and for multiple other purposes. There are more than 50 different types of benzodiazepines but 15 members of this group are marketed in the United States and are classified as Schedule IV drugs. The most commonly prescribed benzodiazepines in the United States are diazepam, temazepam, alprazolam, lorazepam and clonazepam. Benzodiazepines are positive modulators of the GABAA receptors and cause sedation, impaired memory and cognition, and loss of inhibition. These drugs may also cause increased agitation and insomnia, especially in pediatric and elderly populations. Benzodiazepines, like barbiturates, can be short acting or long acting. Short acting benzodiazepines are generally prescribed to treat insomnia. Long acting benzodiazepines are alprazolam, chlordiazepoxide, clorazepate, diazepam, halazepam, lorazepam, oxazepam, prazepam, and quazepam. These drugs are used for treating both insomnia and anxiety disorder while benzodiazepines such as clonazepam, diazepam, and clorazepate are also used as anticonvulsants. Long term treatment with benzodiazepines results in tolerance and dependence in the patient. Benzodiazepines have moderate potential for abuse and the most commonly abused benzodiazepines are alprazolam, diazepam, lorazepam, oxazepam, and triazolam. Chemical structures of commonly abused benzodiazepines are given in Fig. 2.3.
4.1 Pharmacology of Benzodiazepines The half-life of benzodiazepines varies widely depending on the particular drug. Alprazolam has an average half-life of 12 h while average half-life of estazolam, flurazepam, quazepam, temazepam and zolpidem is 16, 1, 36, 11, 2.9 and 2.3 h respectively [16]. Benzodiazepines are extensively metabolized by liver enzymes and are excreted in the urine often as glucuronide conjugate. Oxazepam, which is
18
2 Pharmacology of Commonly Abused Drugs H3 C
CH3
N
O
N
N N
N
Cl N
Cl
Alprazolam H3 C
Diazepam N
O
H N
N N
OH Cl
N
N
Cl
Cl
Triazolam
Oxazepam
Fig. 2.3 Structures of common benzodiazepines
also a common metabolite of both diazepam and temazepam, is an active metabolite. Oxazepam is then conjugated and is excreted in urine as oxazepam glucuronide. Diazepam is also metabolized to nor-diazepam which is an active metabolite. Clorazepate is metabolized to active metabolite nor-diazepam which is then further metabolized to oxazepam. Chlordiazepoxide is metabolized to nor-chlordiazepoxide and demoxepam which are both active metabolites. Then demoxepam is further metabolized to nor-diazepam and then nor-diazepam is subsequently metabolized to oxazepam. Alprazolam is metabolized to two hydroxylated metabolites; 4-hydroxy-alprazolam and α-hydroxy-alprazolam. Both metabolites are active but the activities are lower than the parent drug. Therefore clinical activity of alprazolam is mostly due to the parent compound [17]. Major metabolites of commonly abused benzodiazepines are listed in Table 2.1.
4.2 Benzodiazepine Overdose and Fatality Benzodiazepines are widely prescribed worldwide. Therefore, hospital admission due to benzodiazepine overdose is common. There is a positive association between benzodiazepine use and driver-responsible fatalities from motor vehicle accidents.
5
Cannabinoids
19
In England, benzodiazepine overdose caused 3.8% of all death caused by a single drug overdose [18]. Carlsten et al. reported that in Sweden, benzodiazepines were implicated in 216 out of 548 of the drug related suicides among the elderly (over 65 years) between 1992 and 1996. Death reports revealed that flunitrazepam and nitrazepam were implicated in 90% of the single benzodiazepine related suicides. The authors concluded that benzodiazepines, especially flunitrazepam and nitrazepam, are commonly encountered in suicide by the elderly and should be prescribed with caution in this age group of patients [19]. Martello et al. described the fatality of a 68-year-old woman due to ingestion of flurazepam. The postmortem heart blood flurazepam concentration was 2.8 μg/mL, while the urine concentration was 172 μg/mL in a 68-year-old woman [20].
5 Cannabinoids Psychoactive products obtained from the plant Cannabis sativa (marijuana) have been used for euphoric effect for over 4,000 years, and are currently the most widely used illicit drugs in the U.S. Cannabinoids refers to over 100 related compounds found in the extract of cannabis plant which are lipid soluble and the most psychoactive compound is 9 -tetrahydrocannabinol (THC). Marijuana cigarettes are made from the leaves and flowering tops of the plant, while hashish and hash oil are prepared from a concentrated resin and a lipid-soluble extract and THC is the most psychoactive component of marijuana. The most potent form of marijuana, known as sinsemilla, is prepared from dried parts of mostly indoor-grown female plants. When smoked, THC is quickly absorbed from the lungs into the bloodstream, from which it rapidly distributes into tissue. THC exerts its effect by binding to specific cannabinoid receptors in the brain. Interestingly, both THC and opioids produce an analgesic effect through G-protein coupled mechanisms that block propagation of neurotransmitters causing pain in the brain and spinal cord. It is assumed that the analgesic effect of THC may also be due to interaction of THC with delta and kappa opioid receptors [21].
5.1 Metabolism of THC Pulmonary assimilation of inhaled THC produces maximum plasma concentrations within minutes and psychotropic effects reach a maximum after 15–30 min and may last for 2–3 h. THC is rapidly metabolized by cytochrome P 450 enzymes (mostly CYP3A4, CYP2C9 and CYP2C11) to 11-hydroxy-9 tetrahydrocannabinol (11-OH−THC), an equipotent psychoactive metabolite and also to 11-nor-9-carboxy-9 -tetrahydrocannabinol (THC−COOH), an inactive metabolite. Smaller quantities of other metabolites have also been isolated. Usually THC−COOH is found in the urine in conjugated form. Chemical structures of THC and its major metabolite are given in Fig. 2.4.
20
2 Pharmacology of Commonly Abused Drugs CH3
Fig. 2.4 Chemical structure of THC (tetrahydrocannabinol) and its metabolite THC−COOH
OH
H3C H3C
O
CH3 THC
COOH OH
H3C H3C
O
CH3 THC-COOH
5.2 THC Overdose THC impairs cognition, psychomotor skill and driving performance in a dose related manner. Research has established that the presence of THC in blood, especially in higher amounts, are three to seven times more likely to be responsible for their crash as compared to drivers who had not used drugs or alcohol. Epidemiological studies established that combined use of THC and alcohol produces sever impairment of cognitive, psychomotor, and actual driving performance, sharply increasing the crash risk [22]. THC has been detected in the blood of drivers after fatal crashes. MacInnes et al. reported fatal coronary artery thrombosis associated with cannabis smoking [23].
6 Cocaine Cocaine is an alkaloid found in the leaves of Erythroxylon coca, a shrub indigenous to many parts of South America but primarily Bolivia and Peru. Indigent people of South America chewed coca leaf for recreational purpose for many centuries. Cocaine was first isolated from the coca leaf in 1855. Sigmund Freud famously proposed its use to treat depression and alcohol dependence, but the realities of cocaine addiction quickly brought this idea to an end. Currently, there is no prescription medication that contains cocaine. Cocaine is only used as a topical anesthetic in ear nose and throat surgery, in ophthalmologic procedure or in skin suturing.
6
Cocaine
21
Cocaine exerts its pharmacological effects by blocking reuptake of the neurotransmitters dopamine and norepinephrine, which raises blood pressure, heart rate, and body temperature. Cocaine is a Schedule II drug due to its high abuse potential. Cocaine is abused as the hydrochloride salt which can be snorted. Crack cocaine is a form of cocaine which has not been neutralized by acid to produce the hydrochloride salt. Crack cocaine comes as rock crystal which can be heated and smoke can be inhaled for euphoria. The term “crack cocaine” comes from the cracking sound which crack cocaine produces during heating. Repeated abuse of cocaine may alter brain chemistry including dopamine, gamma-aminobutyric acid (GABA) and glutamate regulation of pyramidal cell activity [24].
6.1 Pharmacology of Cocaine Cocaine has a short half-life (0.5–1.5 h) and is rapidly deactivated by plasma butyrylcholinesterase into ecgonine methyl ester. Another major metabolite of cocaine, benzoylecgonine, probably arise spontaneously in plasma by hydrolysis of cocaine in vivo. Benzoylecgonine along with ecgonine methyl ester represents major urinary excretion of cocaine. A small amount of unchanged cocaine can also be recovered in urine. A small amount is cocaine is also metabolized by liver enzymes into nor-cocaine. Other minor metabolites of cocaine include p-hydroxy-cocaine, m-hydroxy-cocaine, p-hydroxy-benzoylecgonine and m-hydroxy-benzoylecgonine [25]. Major metabolites of cocaine are listed in Table 2.1. Chemical structure of cocaine and its major metabolite benzoylecgonine are given in Fig. 2.5.
N
CH3 O C
OCH3 O
O
Cocaine N
CH3 COOH O
Fig. 2.5 Chemical structures of cocaine and benzoylecgonine
O Cocaethylene
22
2 Pharmacology of Commonly Abused Drugs
6.2 Abuse of Cocaine and Alcohol Simultaneous abuse of cocaine and alcohol (ethanol) causes more toxicity compared to abuse of cocaine or alcohol alone and such combined use abuse results in significant increases in morbidity and mortality. The combined effect of cocaine and alcohol in humans is related to the formation of cocaethylene, which is formed by transesterification of benzoylecgonine by ethanol in the presence of liver carboxylesterase. Chemical structures of cocaine, benzoylecgonine and cocaethylene are given in Fig. 2.5.
6.3 Fatality from Cocaine and Cocaethylene Cocaine is frequently encountered in fatal drug overdose. In a case report of a 26-year-old woman who died from recreational use of cocaine, the postmortem blood cocaine level was 330 μg/mL. This is an extremely high blood cocaine level. Blood levels of benzoylecgonine and ecgonine methyl esters were 50 and 18 μg/mL respectively [26]. Body stuffers, also referred to as “body packers” are drug smugglers, who swallow packets containing illegal drugs to escape detection by the authorities during border crossing or going thorough customs in an international airport. Sometimes these containers may break inside the body, causing a massive overdose which may often be fatal. This is referred to as “body stuffer’s syndrome” and cocaine is the most commonly encountered drug. There are several fatal cases of cocaine overdose in body packers reported in the literature [27]. Mixing cocaine and alcohol is a deadly combination. Cocaethylene is found in plasma only after simultaneous abuse of cocaine and alcohol. Cocaethylene is psychoactive and has a plasma half-life three to five times longer than cocaine and, due to intense and prolonged euphoria, abusers prefer to mix cocaine with alcohol. However, cocaethylene may cause seizure, liver damage and affect the immune system. It also carries an 18- to 25-fold increase over cocaine alone in the risk of immediate death [28]. Cocaethylene is often found in high amounts in fatal overdoses of abusers.
7 Opiates Opiates consist of naturally-occurring or semi-synthetic alkaloids derived from opium, which is found in the latex (a milky fluid) collected from immature seed capsules of poppy plants (Papaver somniferum) 1−3 weeks after flowering by incision of green seed pods. More than 20 alkaloids have been isolated from Papaver somniferum out of which three alkaloids − morphine, codeine and noscapine (antitussive) − are used in therapy. Morphine, the principal natural opiate, is the structural building block for many of the semi-synthetic opioids including heroin, oxycodone, oxymorphone, hydrocodone, hydromorphone, and levorphanol. Opioids
7
Opiates
23
interact with the family of opioid receptors (mu, delta, and kappa). Opioid receptor agonists typically produce analgesia, while antagonists block this response. In addition to potent analgesic properties, opiates can also cause sedation, euphoria, and respiratory depression. which gives opiates a high abuse potential. Long-term use can lead to tolerance and both physical and psychological dependence. Morphine is available for administration in oral form but its effect is usually diminished when given orally. Usually morphine is administered as an intravenous injection. However, codeine, hydromorphone and oxycodone can be administered orally. The major analgesic effect of codeine is due to its active metabolite morphine. Heroin has little oral bioavailability because it is subjected to complete first pass metabolism. The heroin abuser takes this drug by injection. Chemical structures of codeine and morphine are given in Fig. 2.6. Fig. 2.6 Chemical structure of morphine, codeine, and methadone
HO
O N
CH3 CH3
HO H3C
H3C
N CH3
Morphine
O
H3CO Methadone O N
CH3
HO Codeine
7.1 Pharmacology of Opiates Morphine is conjugated and excreted in the urine as morphine-3-glucuronide. Heroin is metabolized to 6-acetylmorphine and then to morphine by hydrolysis of ester linkage by pseudocholinesterase in serum and also in liver by human carboxylesterase-1 and carboxylesterase-2. A small part of morphine (less than 5%) is nor-morphine but the majority of morphine is excreted in urine as morphine-3glucuronide. This metabolite is form by conjugation in the liver by the action of liver enzyme uridine diphosphate glucuronosyltransferase. Codeine is metabolized
24
2 Pharmacology of Commonly Abused Drugs
to morphine in the liver mostly by CYP2D6 [29]. Hydromorphone is also excreted in urine mostly in the conjugated form but a small part of free hydromorphone can also be recovered in urine. Oxycodone is metabolized to oxymorphone which is then conjugated in the liver. Another metabolite of oxycodone is nor-oxycodone which is relatively inactive. Major metabolites of opiates are listed in Table 2.1.
8 Methadone Methadone, a synthetic opioid, is structurally unrelated to the natural opiates but is capable of binding to opioid receptors. These receptor interactions create many of the same effects as seen with natural opiates, including analgesia and sedation. However, methadone does not produce feelings of euphoria and has substantially fewer withdrawal symptoms than opiates such as heroin. Methadone is used clinically to relieve pain, to treat opioid abstinence syndrome, and to treat heroin addiction in the attempt to wean patients from illicit drug use. Methadone is available as a racemic mixture but most of activity is due to the R isomer. In addition, methadone also acts as agonist of N-methyl-D-aspartate receptors which may increase effectiveness of methadone in treating neuropathic pain. See Fig. 2.6 for chemical structure of methadone.
8.1 Pharmacology of Methadone Oral bioavailability of methadone is 60–70%. Methadone is strongly bound to serum proteins, mostly α1 -acid glycoprotein. For treatment of heroin and opiate dependency, methadone can be administered orally once a day but for pain management more frequent dosing is needed. The elimination half-life of methadone is 15–55 h but the effect of analgesia lasts only for 4–6 h. Methadone is mostly metabolized in the liver by cytochrome P 450 enzymes, especially by CYP3A4 but also to a lesser extent by CYP2D6. Moreover, methadone is also metabolized in the intestines. The methadone half-life may be prolonged in approximately 10% of the Caucasian population who are poor metabolizers and who have low activity of CYP2D6 [30]. Patients taking methadone excrete both the parent drug and the major metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in urine. Clinically, it is important to measure both compounds, as methadone excretion varies widely with dose, metabolism, and urine pH.
9 Phencyclidine Phencyclidine (PCP) was developed in the 1950s as a human anesthetic but was discontinued soon thereafter due to serious psychological side effects. In contrast to amphetamine induced psychosis, PCP induced psychosis incorporates both positive
10
Propoxyphene
25
(hallucination, paranoia) and negative (emotional withdrawal, motor retardation) effects. PCP undergoes extensive metabolism by liver cytochrome P 450 enzymes (especially CYP3A4) into several hydroxy metabolites including cis-1-(1phenyl-4-hydroxycyclohexyl)piperidine, trans-1-(1-phenyl-4-hydroxycyclohexyl) piperidine, 1-(1-phenylcyclohexyl)-4-hydroxypiperidine and 5-(1-phenylcycloh exylamino)pentanoic acid. The elimination half-life of PCP varies significantly in humans (7–57 h; average 17 h) [31]. Chemical structure of PCP is given in Fig. 2.7. Fig. 2.7 Chemical structures of PCP and propoxyphene N
Phencyclidine (PCP)
O CH3
H3C O
N CH3
CH3
Propoxyphene
10 Propoxyphene Propoxyphene which is structurally similar to methadone and binds to opiate receptors is administered orally for treating mild to moderate pain and was approved by the FDA in 1957. Propoxyphene exists as an optical isomer where D-propoxyphene has analgesic activity and is used in pain management while the L isomer is devoid of analgesic activity and is used medically as an antitussive agent. Propoxyphene is used alone or in combination with acetaminophen for pain control. Propoxyphene has approximately 33–50% of the potency of codeine. After oral administration, peak plasma concentrations of propoxyphene can be observed after 2 h and the average plasma half-life is 15 h. Propoxyphene is metabolized by the liver enzyme mainly by CYP2D6 to nor-propoxyphene. Propoxyphene is both a substrate and an inhibitor of CYP2D6 and has pharmacokinetically important drug interactions
26
2 Pharmacology of Commonly Abused Drugs
with drugs that are metabolized via CYP2D6. Nor-propoxyphene has a substantially longer half-life than propoxyphene and this metabolite tends to accumulate in plasma of patients with renal impairment. Nor-propoxyphene is an active metabolite and has more cardiac toxicity than propoxyphene and can initiate pulmonary edema, apnea, cardiac arrest and death. Propoxyphene should not be prescribed to patients who are suicidal or prone to addiction. Moreover, this drug should be prescribed with extreme caution to patients taking antidepressants or tranquilizers or who are abusing alcohol. Prolonged use of this drug may cause dependence. Unfortunately, due to the euphoric effect of propoxyphene, this drug is also abused [32]. See Fig. 2.7 for structure.
11 Methaqualone Methaqualone is considered as a sedative hypnotic drug with pharmacological effects similar to barbiturates. This drug was originally synthesized as an antimalarial agent. Methaqualone was introduced in 1954 in the United States but due to its high abuse potential this drug was discontinued in 1984 and was classified as a Schedule I drug with no known medical use. In the 1960 s and 1970 s methaqualone was a popular street drug in the United States [33]. Methaqualone is known as Mandrax in South Africa. Although oral abuse of methaqualone is decreasing in Western countries, the practice of smoking methaqualone is a serious public health issue in South Africa, other parts of Africa and India [34].
12 Glutethimide Glutethimide was introduced in the United States in 1954 as a safe alternative to barbiturates. However, this drug also has a high abuse potential and was widely abused in the United States. In 1991, glutethimide was transferred to a Schedule II drug which now has little medical use. Abuse of oral combination of glutethimide and codeine commonly referred to as “sets” was on the rise in the 1970s and 1980s in the United States. The glutethimide/codeine combination produces euphoric effect comparable to heroin but is longer in duration. This effect may be related to induction of liver enzyme, most likely CYP2D6, which is responsible for the metabolization of codeine to its more active metabolite morphine. Moreover, glutethimide may also inhibit conjugation of morphine to form the inactive metabolite morphine-3-glucuronide.
13 Conclusions Amphetamines, cocaine, marijuana, opiates and to a lesser extent PCP are widely abused and are in the list for federal workplace drug testing. In addition, benzodiazepines and barbiturates are also abused. Methaqualone and gluthemide,
References
27
although widely abused in the past, are currently less abused. Knowledge of the pharmacology of these abused drugs is critical in understanding workplace drug testing.
References 1. de la Torre R, Farre M, Navarro M, Pacifici R et al. Clinical pharmacokinetics of amphetamine and related substances: monitoring in conventional and non conventional matrices. Clin Pharmacokinetic 2004; 43:157–185 2. Green CE, LaValley SE, Tyson CA. Comparison of amphetamine metabolism using isolated hepatocytes from five species including human. J Pharamacol Exp Ther 1986; 237: 931–936. 3. Maresove V, Hampl J, Chundela Z, Zrcek F et al. The identification of a chlorinated MDMA. J Anal Toxicol 2005; 29: 353–358. 4. Bossong MG, Van Dijk JP, Niesink RJ. Methylone and mCPP, two new drugs of abuse. Addict Biol 2005; 10: 321–323. 5. Theobald DS, Fehn S, Maurer HH. New designer drug 2,5-dimethoxy-4propylthio-βphenylethylamine (2C-T-7): studies on its metabolism and toxicological determination in rat urine using gas chromatography/mass spectrometry. J Mass Spectrom 2005; 40: 105–116. 6. de la Torre R, Farre M, Roset PN, Pizarro N et al. Human pharmacology f MDMA: pharmacokinetics, metabolism and disposition. Ther Drug Monit 2004; 26: 137–144. 7. Carmo H, Brulport M, Hermes M, Oesch F et al. CYP2D6 increases toxicity of designer drug 4-methylthioamphetamine (4-MTA). Toxicology 2007; 229: 236–244. 8. Tominaga GT, Garcia G, Dzierba A, Wong J. Toll of methamphetamine on the trauma system. Arch Surg 2004; 139: 844–847. 9. Kojima T, Une I, Yashiki M, Noda J et al. A fatal methamphetamine poisoning associated with hyperpyrexia. Forensic Sci Int 1984; 24: 87–93. 10. Byard RW, Gilbert J, James R, Lokan RJ. Amphetamine derivative fatalities in South Australia-is “Ecstasy” the culprit? Am J Forensic Med Pathol 1998; 19: 261–265. 11. Nemeroff CB. The role of GABA in the pathophysiology and treatment of anxiety disorders. Psychopharmacol Bull 2003; 37: 133–146. 12. Freudenthal RI, Carroll FI. Metabolism of certain commonly used barbiturates. Drug Metab Rev 1973; 2: 265–278. 13. Romain N, Giroud C, Michaud K, Mangin P. Suicide by injection of a veterinarian barbiturate euthanasia agent: report of a case report and toxicological analysis. Forensic Sci Int 2003; 131: 103–107. 14. Brandt-Casadevall C, Krompecher T, Giroud C, Mangin P. A case of suicide disguised as natural death. Sci Justice 2003; 43: 41–143. 15. Tracqui A, Kintz P, Mangin P, Lugnier AA et al. A fatality involving secobarbital, nitrazepam and codeine. Am J Forensic Med Pathol 1989; 10: 130–133. 16. Wang JS, Devane CL. Pharmacokinetics and drug interactions of the sedative hypnotics. Psychopharmacol Bull 2003; 37: 10–29. 17. Greenblatt DJ, von Moltke LL, Harmatz JS, Ciraulo DA. Alprazolam pharmacokinetics: metabolism and plasma levels: clinical implications. J Clin Psychiatry 1993; 54(Suppl): 4–11. 18. Charlson F, Degenhardt L, McLaren J, Hall W et al. A systematic review of research examining benzodiazepine-related mortality. Pharmacoepidemiol Drug Saf 2009; 18: 93–103. 19. Carlsten A, Waern M, Holmgren P, Allebeck P. The role of benzodiazepines in elderly suicide. Scand J Public Health 2003; 31: 224–228. 20. Martello S, Oliva A, De Giorgio F, Chiarotti M. Acute flurazepam intoxication: a case report. Am J Forensic Med Pathol 2006; 27: 55–57. 21. Cichewicz DL. Synergistic interactions between cannabinoid and opioid analgesics. Life Sci 2004; 74: 1317–1324.
28
2 Pharmacology of Commonly Abused Drugs
22. Ramaekers JG, Berghaus G, van Laar M, Drummer OH. Dose related risk of motor vehicle crashes after cannabis use. Drug Alcohol Depend 2004; 73: 109–119. 23. MacInnes DC, Miller KM. Fatal coronary artery thrombosis associated with cannabis smoking. J R Coll Gen Pract 1984; 34(267): 575–576. 24. Steketee JD. Cortical mechanism of cocaine sensitization. Crit Rev Neurobiol 2005; 17: 69–86. 25. Kolbrich EA, Barnes AJ, Gorelick DA, Boyd SJ. Major and minor metabolites of cocaine in human plasma following controlled subcutaneous cocaine administration 26. Peretti FJ, Isenschmid DS, Levine B, Caplan YH. Cocaine fatality: an unexplained blood concentration in a fatal overdose. Forensic Sci Int 1990; 48: 135–138. 27. Fineschi V, Centini F, Monciotti F, Turillazzi E. The cocaine “body staffer” syndrome: a fatal case. Forensic Sci Int 2002; 126: 7–10. 28. Andrews P. Cocaethylene toxicity. J Addict Dis 1997; 16: 75–84. 29. Kreek MJ, Bart G, Lilly C, LaForge KS et al. Pharmacogenetics and human molecular genetics of opiate and cocaine addictions and their treatments. Pharmacol Rev 2005; 57: 1–26. 30. Brown P, Kraus C, Fleming M, Reddy S. Methadone: applied pharmacology and use as adjunctive treatment in chronic pain. Postgrad Med J 2004; 80: 654–659. 31. Laurenzana LM, Owens SM. Metabolism of phencyclidine by human liver microsomes. Drug Metab Dispos 1997; 25: 557–563. 32. Barkin EL, Barkin SJ, Barkin DS. Propoxyphene (dextropropoxyphene): a critical review of a weak analgesic that should remain in antiquity. Am J Ther 2006; 13: 534–542. 33. Ionescu-Pioggia M, Bird M, Orzack MH, Benes F et al. Methaqualone. Int Clin Psychopharmacol 1988; 3: 97–109. 34. McCarthy G, Myers B, Siegfried N. Treatment of methaqualone dependance in adults. Cochrane Database Syst Rev 2005; 18: CD004146.
Chapter 3
Workplace Drug Testing: SAMHSA and Non-SAMHSA Drugs
Abstract SAMHSA (Substance Abuse and Mental Health Services Administration), a federal agency, regulates federal workplace drug testing and requires testing for amphetamines, cocaine, cannabinoid (marijuana), opiates and phencyclidine (PCP). In addition to these abused drugs, many private employers also test for benzodiazepines, barbiturates, methadone and propoxyphene. Some employers also test for methaqualone and glutethimide. Usually immunoassays are used for screening the presence of these drugs in the urine. If any test is positive, then the presumptive positive drug is confirmed by a second analytical technique preferably by gas chromatography/mass spectrometry (GC/MS). Immunoassays suffer from cross-reactivity of other drugs or related substances and may show positive results. GC/MS is a more sophisticated analytical method and is considered as the gold standard for drug confirmation. Keywords Gas Chromatography/Mass Spectrometry · Phencyclidine · SAMHSA
1 Introduction As many as 15−20% of fatal work-related accidents can be connected to the use of alcohol, narcotics and psychotropic drugs [1]. Drug abuse is an important problem in the workplace because 70% of current illicit drug abusers are employed and approximately 7% of Americans employed in full-time jobs report heavy drinking. Employees who abuse drugs are twice as likely to request time off, and 3.6 times more likely to be involved in a workplace accident. Individuals who use alcohol and/or drugs in the workplace annually cost American business 81 billion dollars in lost productivity [2]. Workplace drug testings deter employees from drug abuse thus reducing job related accidents. A drug testing program is geared towards identifying employees who are using common illicit drugs such as marijuana, cocaine, amphetamines and opiates on a regular basis. Past history of drug abuse is not a concern for most employers and cannot be detected by urine drug testing protocols. A. Dasgupta, Beating Drug Tests and Defending Positive Results, C Springer Science+Business Media, LLC 2010 DOI 10.1007/978-1-60761-527-9_3,
29
30
3 Workplace Drug Testing
2 SAMHSA Mandated Drugs The United States Department of Health and Human Services (DHHS) drug testing standards were published in 1998 and then revised in 1994, 1998, and 2004. In 2004, significant revisions defining standardizing, and specimen validity tests were also included in the report. In addition, in a separate notice, the DHHS proposed to permit laboratory tests of hair, oral fluid, and sweat for the presence of drugs of abuse [3]. SAMHSA (Substance Abuse and Mental Health Services Administration), an agency under the DHHS, mandates guidelines for drugs testing for federal employees as well as certain agencies that receive federal grants. The requirement of federally mandated drug testing is to test for the presence of five drugs/metabolites in the urine including amphetamine, cocaine, opiates, marijuana and phencyclidine. These drugs were known as the five SAMHSA drugs for a long time. The mandatory guideline also dictates the cut-off concentrations of various drugs and metabolites both at the screening and confirmation steps. If the concentration of a particular drug or metabolite is below the cut-off, the drug testing should be reported as negative. Later, SAMHSA published a final notice to the revision of the Mandatory Guidelines for the federal Workplace drug testing programs in the November 25th issue of the federal register (Volume 73) with a proposed implementation date in 2010. In this revision, designer drugs such as 3,4-methylenedioxymethamphetamine (MDMA, ecstasy), 3,4methylenedioxyamphetamine (MDA) and 3,4-methylenedioxyethylamphetamine (MDEA) should also be tested along with amphetamine and methamphetamine. The cut-off concentrations of certain drugs/metabolites were also lowered in this revised guideline. The initial immunoassay screen should be performed using FDA approved commercially available immunoassay kits and the proper instrumentation following manufacturer’s recommendations. If the immunoassay screen is negative, no further testing is required but every positive screening result must be confirmed by a rigorous second analytic technique preferably gas chromatography/mass spectrometry (GC/MS). No additional drug should be tested unless authorized by the law [3]. In Tables 3.1 and 3.2 current cut-off screening and confirmation of various Table 3.1 The screening cut-off concentrations of SAMHSA drugs Drug or drug class Amphetamine/ Methamphetamine MDMA Cannabinoids Cocaine metabolites Opiates 6-Acetylmorphineb Phencyclidine a To
Present cut-off concentration
New cut-off concentrationsa
1000 ng/mL
500 ng/mL
No Guideline 50 ng/mL 300 ng/mL 2,000 ng/mL No guideline 25 ng/mL
500 ng/mL 50 ng/mL 150 ng/mL 2,000 ng/mL 10 ng/mL 25 ng/mL
be implemented in 2010 of heroin, a marker for heroin abuse
b Metabolite
3
Testing of Various SAMHSA Mandated Drugs
31
Table 3.2 The confirmation cut-off concentrations of SAMHSA drugs Drug or drug class
Present concentration
New concentration
Amphetamines Methamphetamine MDMA MDA MDEA Cannabinoids Benzoylecgonine Codeine Morphine 6-Acetylmorphine Phencyclidine
500 ng/ml 500 ng/mL No guideline No guideline No guideline 15 ng/mL 150 ng/mL 2,000 ng/mL 2,000 ng/mL 10 ng/mL 25 ng/mL
250 ng/mL 250 ng/mL 250 ng/mL 250 ng/mL 250 ng/mL 15 ng/mL 100 ng/mL 2,000 ng/mL 2,000 ng/mL 10 ng/mL 25 ng/mL
MDMA: 3,4-metheylenedioxymethamphetamone MDA: 3,4-methylenedioxyamphetamine MDEA: 3,4-methylenedioxyethylamphetamine
drugs of abuse are given along with proposed changes in cut-off concentration to be implemented in 2010.
3 Testing of Various SAMHSA Mandated Drugs Currently, approximately 90% of workplace drug testing is performed using the urine specimen. Drugs are metabolized to various metabolites and, although some metabolites are devoid of any pharmacological properties, the presence of these metabolites in the urine specimen validate abuse of the parent drug by the individual undergoing workplace drug testing. Urine specimens are favored in workplace drug testing because collection of such specimens is non-invasive and the detection windows for the drug or its metabolite is substantially longer in urine compared to blood. However, there are limitations of drugs of abuse testing using urine specimens. In urine, most drugs or metabolites can be detected up to 2–3 days after last use. Drugs can be detected for a longer time in hair specimens but, due to inherent complexity of determining drug concentration in a hair specimen, this alternative matrix for drug of abuse testing is less favored that urine drug testing. Usually a drug or its metabolites can only be detected in urine for a limited time after last abuse. Usually certain abused drugs, for example cocaine, can only be detected 2–3 days after use but for propoxyphene, the drug can be detected for up to 30 days. Usually, after last abuse, most of the PCP is excreted within the first 9 days and then the urinary excretion of PCP and its metabolites are reduced significantly. The mean detection window of PCP in urine is 14 days after last use [4]. Marijuana metabolites can only be detected for 2–3 days after a single use but the metabolite may accumulate in a chronic abuser and the test can be positive for up to 30 days in chronic abusers of marijuana [5]. After a single administration benzoylecgonine may be detected for up to 2 days in urine but after repeated use may be present for
32
3 Workplace Drug Testing
up to 4 days [6]. Usually amphetamine and methamphetamine can be detected in urine for up to 2 days after last use [7]. In the military and a few other circumstances when urine specimen collection is supervised, the chance of adulterating a specimen is slim. In contrast, in most workplace drug testing situations, the person undergoing drug testing is given privacy to collect his or her specimen in the bathroom. Because it is not humanly possible to search each individual thoroughly, it is possible that certain individuals may conceal an adulterant with intention to invalidate drug testing. This book is devoted to discussing various ways people try to beat drug testing and what laboratory professionals and medical review officer can do to catch these cheats.
3.1 Testing of Amphetamines After abuse of amphetamine, the drug is excreted unchanged in the urine along with other metabolites. Methamphetamine after abuse is converted into amphetamine and a significant amount of methamphetamine is also excreted in the urine unchanged. The current screening cut-off of amphetamines is 1,000 ng/mL but in 2010 the cutoff value would be lowered to 500 ng/mL in 2010. The antibodies used in immunoassays for the screening of amphetamines may target methamphetamine or amphetamine. Both amphetamine and methamphetamine exist as optical isomers and only the D isomer is abused. Because of this, all immunoassays use antibody specific for the D isomer. The crossreactivity of MDMA and related drugs may vary between different immunoassays. Several manufacturers also have specific immunoassay for screening of MDMA (ecstasy) and such assays also show high cross-reactivities with related designer drugs. For example, cloned enzyme donor immunoassays (CEDIA) for amphetamine/ecstasy has 67.2% cross-reactivity with amphetamine, 58.4% with methamphetamine, 113% with 3,4-methylenedioxy-amphetamine (MDA), 199% with 3,4-methylenedioxymethamphetamine (MDMA), and 207% cross-reactivity with 3,4-methylenedioxyethylamphetamine [8]. Various other designer drugs with amphetamine like structures also show substantial cross-reactivities with the assay antibody. In another article, the authors demonstrated that Roche Abuscreen ONLINE amphetamine immunoassay (Roche Diagnostics, Indianapolis, IN) has high cross-reactivity with MDA but has low cross-reactivity with MDMA, MDEA as well as with methamphetamine and ethylamphetamine [9]. Another limitation of amphetamine/methamphetamine immunoassays is the significant cross-reactivity with various structurally similar compounds, many of which are available over-the counter. See Chap. 10 for more detail. Urine specimens tested positive for amphetamine/methamphetamine should be further tested for the confirmation of such drugs using gas chromatography/mass spectrometry (GC/MS). The guideline requires that if methamphetamine is confirmed by GC/MS, then amphetamine must be present in the specimen at a concentration of 200 ng/mL or higher in order to report the urine specimen tested for methamphetamine. From a physiological point of view, after methamphetamine
3
Testing of Various SAMHSA Mandated Drugs
33
use, both amphetamine and methamphetamine must be present in the urine. In addition, in the 1990s it was reported that at a high injector port temperature (during GC/MS confirmation step), pseudoephedrine, a common active ingredient of many over the counter cold medications, can be thermally degraded to methamphetamine and may cause methamphetamine positive confirmatory results as an artifact. However, no amphetamine can be generated in this process. Therefore, detection of amphetamine in urine specimens ensures that methamphetamine indeed is the source of amphetamine. The new guideline for confirmation of amphetamine and related compound using GC/MS is 250 ng/mL (Table 3.2). For GC/MS confirmation of various amphetamines, both solid phase and liquidliquid extraction can be used for extracting these compounds from the urine specimen. For liquid-liquid extraction, the pH of the urine is made basic and then a variety of solvents such as 1-chlorobutane can be used for extraction. Amphetamines and related compounds, due to their polarity, can be analyzed directly by GC/MS. Amphetamines and related compounds are optical isomers and can be derivatized using either non-chiral or chiral derivatization agents. Common non-chiral derivatization agents are trichloroacetic anhydride, pentafluoropropionic anhydride, heptafluorobutyric anhydride (HFB) and 4-carboethoxyhexafluorobutyryl chloride (4-CB). Derivatized products are formed from direct interaction of derivatizing agents with the amine functional group of amphetamine compounds. None of the derivatized compounds produce molecular ions. In all cases the masses of the derivatizing agents are more than that of the compound. Therefore, it is important that the fragments chosen represent all parts of the compound. Major ions of 4-CB and HFB derivatives for both amphetamine and methamphetamine are from the benzyl group (m/z 91), m/z 119 (C6 H5 CH2 CH+ CH3 ), m/z 118 (C6 H5 CH=CHCH3 ), and M+ – 91. While ion M+ – 119 is one of the major ions in 4-CB derivatives, it is
122
55 68 60
80
166
226
272
331
100 120 140 160 180 200 220 240 260 280 300 320
Fig. 3.2 Total scan mass spectrum of benzoylecgonine propyl ester. Figure courtesy of Dr. Buddha D. Paul, Office of the Armed Forces Medical Examiner (OAFME), Forensic Toxicology Division of the Armed Forces Institute of Pathology, Rockville, MD
3.4 Testing of Opiates The original cut-off of concentration for opiates for the screening was 300 ng/mL but it was increased to 2,000 ng/mL after reports were published indicating that, after consumption of poppy seed containing foods, urinary opiate level of 300 ng/mL can be easily reached. However, some private employer may still use the 300 ng/mL cut-off in the respective workplace drug testing. Most immunoassays for opiates utilize antibody that recognize morphine-3-glucuronide, the major metabolite after use of codeine, morphine and heroin. Heroin is metabolized to 6-acetylmorphine (also called 6-monoacetylmorphine) which is then metabolized further to morphine and is excreted in urine as a glucuronide conjugate. The presence of 6-acetylmorphine can only be detected for up to 24 h after heroin abuse but morphine is present in urine for up to 2–3 days. The mandatory guideline requires testing for 6-acetylmorphine by GC/MS in urine using a cut-off concentration of 10 ng/mL.
3
Testing of Various SAMHSA Mandated Drugs
37
Morphine-3-glucuronide (conjugated form of morphine, the major metabolite in urine), codeine and 6-acetylmorphine have high cross-reactivity with morphine antibody and all if present in urine produces positive opiate screening results. Most opiate immunoassays have poor cross-reactivity with oxycodone and relatively low cross-reactivity with hydromorphone and hydrocodone. If these compounds are present in high amounts in urine, the specimen may test positive for opiates. There are specific immunoassays for detecting the presence of oxycodone in urine because pain medicine oxycodone is also widely abused. There are several synthetic opioids which are not metabolized to morphine and codeine. These drugs include buprenorphine, fentanyl and its derivatives, meperidine (Demerol), methadone and oxymorphone. Therefore abuse of these drugs cannot be detected by opiate screening assays. Because morphine is present mostly in conjugated form, acid hydrolysis or enzymatic hydrolysis is carried our prior to extraction of this metabolite and related compounds from urine specimens. The codeine and the pool of free morphine are then derivatized for a better chromatographic separation. Acetylation, propionylation, and pentafluoropropionylation at the 6-hydroxy group of codeine are common derivatives used for GC/MS confirmation of these drugs. Fragmentations are similar for all three compounds. Heroin after ingestion metabolizes to 6-acetylmorphine and morphine. Morphine is also a urinary product of morphine or codeine ingestion. Therefore, 6-acetylmorphine is unique to heroin metabolism. Propionylation to 3-propionyl-6-acetylmorphine and pentafluoropropionylation to 3-pentafluoropropionyl-6-acetylmorphine are the most common derivatization procedures. Oxycodone after ingestion is metabolized to oxymorphone and its conjugates. The conjugates are hydrolyzed by acid to increase the amount of free hydromorphone. The derivatization is a two step process. Initially, the 6-ketones of the keto-opiates are transformed to methoxime by heating the urine solution with methoxylamine (>C=O to >C=N−OCH3 ). After extraction through solid phase and evaporation, the oxycodone and oxymorphone are again derivatized by acetic anhydride to oxycodone-6-methoxime-9-acetyl and oxymorphone-6-methoxime3,9-diacetyl- derivatives, respectively. The oxycodone derivative shows a strong molecular ion (M+ 386) with fragment ions m/z 343 (M+ – COCH3 ), 327 (M+ – OCOCH3 ), and 295 (M+ –CH3 COOH – OCH3 ). In the oxymorphone derivative, the predominant ion is m/z 372 (M+ – 42, M+ –CH2 −CO). Other ions are the molecular ion (M+ 414), and fragment ions m/z 371 (M+ – COCH3 ), 329 (M+ – 42 – COCH3 ), 355 (M+ −OCOCH3 ), and 281 (M+ − 42 – CH3 COOH – OCH3 ).
3.5 Testing of Phencyclidine Phencyclidine (PCP) is abused by snorting, smoking, intravenous injection and also by being taken orally. PCP is absorbed into the circulation after intake by any one of these routes. PCP is metabolized by the liver to various hydroxylated metabolites but a portion of PCP is also excreted unchanged in the urine. PCP tests targets
38
3 Workplace Drug Testing
the unchanged drug for detection both in immunoassay screens as well as in GC/MS confirmatory tests. For GC/MS analysis, deuterated PCP is usually used as the internal standard and a molecular ion is observed at m/z 243. The cut-off concentration for both screening and confirmation is 25 ng/mL.
4 Testing of Non-SAMHSA Drugs Most common non-SAMHSA drugs tested by private employers are barbiturates and benzodiazepines. In addition, testing of methadone and propoxyphene are also common. Less commonly monitored drugs are methaqualone and glutethimide. The window of detection of short acting barbiturates such as pentobarbital in urine is 1 day while a long acting barbiturate such as phenobarbital has a detection window of 1 month. Similarly, a long active benzodiazepine such as diazepam can be detected in the urine for up to 30 days (Table 3.3).
4.1 Testing of Barbiturates Barbiturates are central nervous system depressants which were the first class of drugs available as sedative/hypnotic agents. Barbiturate use for this purpose has Table 3.3 Window of detection of various drugs of abuse in the urine specimen Drug
Detection window in urine
Amphetamine Methamphetamine
2 days 2 days
Barbiturates Short acting (for example, pentobarbital) Long acting (for example, phenobarbital)
1 day 21 days
Benzodiazepines Short cting (for example, Alprazolam, Lorazepam) Long acting (for example, diazepam, etc.) Marijuana (As 11-nor-9 -tetrahydrocannabinol- 9-carboxylic acid) Cocaine (as benzoylecgonine) Opiates Morphine Codeine Heroin (as morphine) Methadone Oxycodone Phencyclidine Methaqualone Propoxyphene
3 days 30 days 2–3 days after single use 30 days in chronic abuser 2 days after single use 4 days after repeated use 2–3 days 2 days 2 days 3 days 2–4 days 14 days 3 days 6 h–2 days
4
Testing of Non-SAMHSA Drugs
39
been largely replaced by benzodiazepines, a class of drugs with a higher therapeutic index and lesser side effects. Barbiturates are still used to treat seizures, migraine headaches, and to induce anesthesia in surgical procedures. Typical barbiturates that are used are pentobarbital, amobarbital, secobarbital and phenobarbital. The Department of Defense discontinued testing for barbiturates in 2005 for the military drug testing program because prevalence of use was low. Barbiturates are classified as ultra-short acting, short-acting and intermediate-acting. Barbiturates are administered both orally and intravenously with high bioavailability. Barbiturates are metabolized via oxidation followed by conjugation and primary excretion in urine [17]. Initial screening for the presence of barbiturates in urine specimens is carried out using various immunoassays and is very reliable for this purpose. These immunoassays are usually calibrated with secobarbital but demonstrate significant cross-reactivities with other barbiturates. Confirmation testing for barbiturates is most commonly performed using GC–MS analysis following either liquid/liquid or solid phase extraction. Liquid/liquid extraction is performed at an acidic/neutral pH with small volumes of specimens. Solid phase extraction can be performed using silica based and copolymer based columns. Alkylation is the most common derivatization technique used for barbiturates to allow for improved chromatography and deuterated barbiturates are used as internal standards. Methylation of barbiturates can be easily carried out using iodomethane/tetramethylammonium hydroxide in dimethylsulfoxide. The deuterated pentobarbital (pentobarbital-d5 ) can be used as the internal standard [18]. In Fig. 3.3 the total ion chromatogram for methylated barbiturates is given to show resolution of various barbiturates by capillary column.
Abundance 95000 90000 85000 80000 75000 70000 65000 60000 55000 50000 45000 40000 35000 30000 25000 20000 15000 10000 5000 Time-->
pentobarbital
amobarbital
secobarbital
butalbital phenobarbital
cyclopal
5.00
6.00
7.00
methylphenytoin
phenytoin
8.00
9.00
10.00
11.00
12.00
Fig. 3.3 GC–MS total ion chromatogram for methylated barbiturates at 2 mg/L in blood. Figure courtesy of Dr. Buddha D. Paul, Office of the Armed Forces Medical Examiner (OAFME), Forensic Toxicology Division of the Armed Forces Institute of Pathology, Rockville, MD
40
3 Workplace Drug Testing
4.2 Testing of Benzodiazepines For commercially available immunoassays the target analyte is typically oxazepam or nordiazepam. The disadvantage of most benzodiazepine immunoassays is that they are designed to cross react with unconjugated drugs. The addition of β-glucuronidase to the screening reagent will allow for enzymatic hydrolysis prior to analytical measurement by cleaving the glucuronide conjugated metabolites, thus R ) is a benzodiazepine which improving sensitivity [19]. Flunitrazepam (Rohypnol is not legally available in the United States. However, this drug is found on the clandestine market and is widely abused in the United States and is also associated with date rape situations. One of the major metabolite of flunitrazepam is 7-aminoflunitrazepam which cross-reacts with antibodies used in the benzodiazepine screening assays. For example, cross-reactivity of 7-aminoflunitrazepam with EMIT Plus assay is 67.8%, and the corresponding cross-reactivity with CEDIA assay is 99%. Unfortunately, due to low concentrations of flunitrazepam and its major metabolite 7-aminoflunitrazepam, an immunoassay for benzodiazepine may fail to detect the presence of flunitrazepam in urine. There are commercially available immunoassays on the market, for example, a specific enzyme-linked immunosorbent assay marketed by Cozart Bioscience Ltd (Oxfordshire, UK) for the screening of flunitrazepam in urine [20]. For GC/MS confirmation, benzodiazepines can be extracted from biological specimens by either liquid/liquid or solid-phase extraction. Prior to extraction of urine specimens, a hydrolysis step must be completed to cleave the glucuronide conjugation. Most procedures use an enzymatic hydrolysis because it is a weaker reaction than acid hydrolysis which can convert some benzodiazepines to benzophenones. Adjustment of pH following hydrolysis is necessary for both extraction techniques. Derivatization is not required for some benzodiazepines such as diazepam and midazolam but it is necessary for others, including 7-aminoclonazepam and α-hydroxyalprazolam. Popular derivative choices are alkyl, acyl, and silyl derivatives.
4.3 Testing of Methadone Methadone is metabolized to two pharmacologically inactive urinary metabolites, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl3,3-diphenylpyrrolidine (EMDP). Usually both methadone and EDDP are found in urine in significant amounts while the concentration of EDMP is relatively low. Cheng et al. reported that urinary methadone concentration varied from 78 to 9,547 ng/mL (median: 1,031 ng/mL) and EDDP concentration varied from 77 to 9,547 ng/mL (median: 6,734 ng/mL) in 21 urine specimens collected from patients undergoing methadone maintenance therapy. The concentrations of EMDP were below the detection limit of the GC/MS assay [21]. Commercially available immunoassays for screening of methadone in urine have antibodies either directed
4
Testing of Non-SAMHSA Drugs
41
towards methadone or EDDP. However, an immunoassay designed for detecting the presence of methadone in urine may have a low cross-reactivity with EDDP.
4.4 Testing of Propoxyphene Propoxyphene is used for treating mild to moderate pain but this drug is also abused. Both propoxyphene and its metabolite nor-propoxyphene can be observed in urine and in most immunoassays the target analyte is propoxyphene. The cross-reactivity of the antibody with nor-propoxyphene may vary widely between different immunoassays. McNally et al. concluded that the ONLINE propoxyphene assay (Roche Diagnostics, Indianapolis, IN) has better sensitivity that the EMIT propoxyphene assay for detecting the presence of propoxyphene in urine because the antibody used in the ONLINE assay has 77% cross-reactivity with nor-propoxyphene while the EMIT assay has only 7% cross-reactivity R ) interferes with the with nor-propoxyphene [22]. Diphenhydramine (Benadryl EMIT propoxyphene immunoassay [23]. The confirmation of the presence of propoxyphene in urine should be carried out by GC/MS and the assay should be able to determine the concentration of both propoxyphene and its major metabolite nor-propoxyphene.
4.5 Testing of Methaqualone and Glutethimide Methaqualone is metabolized to 2 -hydroxy and 3 -hydroxy metabolites which are then conjugated and excreted in urine as glucuronide. Brenner et al. reported that both Roche ONLINE methaqualone immunoassay and EMIT II methaqualone immunoassay have high cross reactivity toward both 2- and 3-hydroxy metabolites of methaqualone as well as their conjugated form and are useful for screening of methaqualone in urine specimens. When volunteers received 200 mg of methaqualone, both immunoassays showed greater than 600 ng/mL of drug after the second void and all urine specimens tested highly positive (at a 300 ng/mL cut-off) for 72 h. When the specimens were analyzed by GC/MS without hydrolysis of glucuronide conjugates, low levels of methaqualone and metabolites were detected. However, when urine specimens were hydrolyzed with beta-glucuronidase and then analyzed again by GC/MS, high concentrations of metabolites were found. Therefore authors recommend hydrolysis of the urine specimen prior to GC/MS analysis [24]. Glutethimide, a sedative, is also abused. It undergoes complex metabolism into several metabolites and some metabolites such as 4-hydroxygluthemide and 2-phenylglutarimide have significant pharmacological activities. Immunoassays can be used for screening for the presence of glutethimide in urine. GC/MS confirmation is also capable of confirming the presence of metabolites along with the parent drug in urine. However, only less than 2% of glutethimide is excreted unchanged in urine.
42
3 Workplace Drug Testing
5 Miscellaneous Issues in Workplace Drug Testing Immunoassay positive test results are considered as presumptive positive and such results must be confirmed by GC/MS in workplace drug testing. The major limitation of immunoassays is the cross-reactivity from structurally related compounds while GC/MS confirmation is free from such limitations (except that optical isomers can be resolved). However, using special derivatization method using chiral derivatization agents, even optical isomers can be analyzed by GC/MS. There are many examples of limitations of immunoassays. For example, amphetamine immunoassays are mostly affected because a number of structurally similar compounds such as buflomedil, brompheniramine, chlorpromazine, ephedrine, fenfluramine, isometheptene, mexiletine, N-acetyl procainamide (metabolite of procainamide), perazine, phenmetrazine, phentermine, phenylpropanolamine, promethazine, pseudoephedrine, quinacrine, ranitidine, tolmetin and tyramine are known to cross-react with various amphetamine assays causing false positive results [25–27]. Dietzen et al. demonstrated that urine specimens containing ranitidine greater than 43 μg/mL interferes with Beckman Synchron amphetamine, but other Beckman assays such as opiate, barbiturates, cocaine metabolite, propoxyphene and methadone have good specificity while the cannabinoid assay has 100% predictive value based on GC/MS confirmation [28]. Tolmetin, a non-steroidal antiinflammatory drug, can interfere with EMIT assays for urine drug screening if the drug is present in a significant amount (1,800 mg/L). Tolmetin has characteristic high molar absorbance at 340 nm which is the wavelength for detection of signal in EMIT assays. A specimen collected from an arthritic patient receiving 100–400 mg tolmetin showed decreased signal when mixed with abused drugs and analyzed by EMIT assays. Similar interference of tolmetin in FPIA assays for drugs of abuse was not observed because a different wavelength (525 nm) is used for detecting signals. However, potential false positive test results using FPIA benzodiazepine assay were observed when urine specimens contained high concentrations of fenoprofen, flurbiprofen, indomethacin, ketoprofen and also tolmetin [29]. If a specimen is tested positive by the immunoassay and tested negative by GC/MS, the specimen is reported as “negative.” If a urine specimen is tested positive, the MRO (medical review officer) must determine that the person is abusing drugs and there is no alternate explanation of analytical positive specimen. There are multiple mechanisms such as chain of custody, review by MRO, etc. which are implemented in workplace drug testing to ensure that an innocent person is not falsely penalized.
6 Conclusions In workplace drug testing, measures are taken to ensure accuracy of the result and, for this purpose, specimen collection process, transportation of specimens to the laboratory, analysis of specimens and reporting of results are all important. The goal
References
43
is to identify employees who are abusing drugs on a regular basis. Immunoassays are used as the initial screening tool but positive results must be confirmed by GC/MS or another acceptable robust analytical technique.
References 1. Ricordel I, Wenzek M. Cannabis and safety work: evolution of its detection within the controls of narcotics since 2004 to the SNCF. Ann Pharm Fr 2008; 66: 255–260. 2. Roberts S, Fallon LF Jr. Administrative issues related to addiction in the workplace. Occup Med 2001; 16: 509–515. 3. Bush DM. The US mandatory guidelines for federal workplace drug testing programs: current status and future considerations. Forensic Sci Int 2008; 174: 111–119. 4. Dackis CA, Pottash AJC, Annitto W, Gold MS. Persistence of marijuana level after supervised abstinence. Am J Psychiatry 1982; 139: 1196–1198. 5. Huestis MA, Mitchell JM, Cone EJ. Detection time of marijuana metabolite in urine by immunoassays and GC–MS. J Anal Toxicol 1995; 19: 443–449. 6. Huestis MA, Darwin WD, Shimoura E, Lalani SA et al. Cocaine and metabolites urinary excretion after controlled smoke administration. J Anal Toxicol 2007; 31: 462–468. 7. Moeller KE, Lee KC, Kissack JC. Urine drug screen: practical guides for clinicians. Mayo Clin Proc 2008; 83: 66–76. 8. Loor R, Lingerfelter C, Wason PP, Tank K et al. Multiplex assay of amphetamine, methamphetamine, and ecstasy drug using CEDIA technology. J Anal Toxicol 2002; 26: 267–273. 9. Lekskulchai V, Mokkhavesa C. Evaluation of Roche Abuscreen ONLINE amphetamine immunoassay for screening of new amphetamine analogs. J Anal Toxicol 2001; 25: 471–475. 10. McGilveray IJ. Pharmacokinetics of cannabinoids. Pain Res Manag 2005; 10(A): 15A–22A. 11. Fraser AD, Worth D. Urinary excretion of 11-nor-9-carboxy-delta9-tetrahydrocannaninol and 11-hydroxy-delta9-THC: cannabinoid metabolites to creatinine ratio stuffy IV. Forensic Sci Int 2004; 143: 147–152. 12. Goodwin RS, Darwin WD, Chiang CN, Shih M et al. Urinary elimination of 11-nor9-cerboxy-delta 9-tetrahydrocannabinol in cannabis users during continuously monitored abstinence. J Anal Toxicol 2008; 32: 562–569. 13. Joern WA. Detection of past and recurrent marijuana use by a modified GC/MS procedure. J Anal Toxicol 1987; 11: 49–52. 14. Cone EJ, Tsadik A, Oyler J, Darwin WD. Cocaine metabolism and urinary excretion after different routes of administration. Ther Drug Monit 1998; 20: 556–560. 15. Wu AH, Ostheimer D, Cremese M, Forte E et al. Characterization of drug interference caused by coelution of substances in gas chromatography/mass spectrometry confirmation of targeted drugs in full scan and selected ion monitoring modes. Clin Chem 1994; 40: 216–220. 16. Dasgupta A, Mahle C, McLemore J. Elimination of fluconazole interference in gas chromatography/mass spectrometric confirmation of benzoylecgonine, the major metabolite of cocaine using pentafluropropionyl derivative. J Foresnsic Sci 1996; 41: 511–513. 17. Jenkins AJ, Cone EJ. Pharmacokinetics: Drug absorption, distribution, and elimination. In: SB Karch ed. Drug Abuse Handbook. CRC Press, Washington, D.C., 1998, pp. 151–201. 18. Liu RH, McKeehan AM, Edwards C, Foster G et al. Improved gas chromatography/mass spectrometric analysis of barbiturates in urine using centrifuge-based solid phase extraction, methylation with d-5 pentobarbital as internal standard. J Forensic Sci 1994; 39: 1504–1514. R KIMS immunoassay with 19. Klette KL. Urine benzodiazepine screening using Roche Online β-glucuronidase hydrolysis and confirmation by gas chromatography – mass spectrometry. J Anal Toxicol 2005; 29: 193–200.
44
3 Workplace Drug Testing
20. Wang PH, Liu C, Tsay WI et al.. Improved screen and confirmation test of 7-aminoflunitrazepam in urine specimens for monitoring flunitrazepam (Rohypnol) in urine. J Anal Toxicol 2002; 26: 411–418. 21. Cheng PS, Lee CH, Liu C, Chen CS. Simultaneous determination of Ketamine, Tramadol, Methadone and their metabolites in urine by gas chromatography-mass spectrometry. J Anal Toxicol 2008; 32: 253–259. 22. McNally AJ, Pilcher I, Wu R, Salamone SJ et al. Evaluation of the online immunoassay for propoxyphene: comparison to EMIT II and GC–MS. J Anal Toxicol 1996; 20: 537–540. 23. Schneider S, Wennig R. Interference of diphenhydramine with the EMIT II immunoassay for propoxyphene. J Anal Toxicol 1999; 23: 637–638. 24. Brenner C, Hui R, Passarelli J, Wu R et al. Comparison of methaqualone excretion patterns using Abuscreen ONLINE and EMIT II immunoassay and GC/MS. Forensic Sci Int 1996; 79: 31–41. 25. Moore KA. Amphetamines/sympathomimetic amines. In: Levine B ed. Principles of Forensic Toxicology. AACC Press, Washington, D.C, 2003, pp. 341–348. 26. Grinstead GF. Ranitidine and high concentration phenylpropanolamine cross react in the EMIT monoclonal amphetamine/methamphetamine assay. Clin Chem 1989; 35: 1998–1999. 27. Joseph R, Dickerson S, Wills R, Frankenfield D et al. Interference by non-steroidal antiinflammatory drugs in EMIT and TDX assays for drugs of abuse. J Anal Toxicol 1995; 19: 13–17. 28. Dietzen DJ, Ecos K, Friedman D, Beason S. Positive predictive values of abused drug immunoassay on the Beckman Synchron in a veteran population. J Anal Toxicol 2001; 25: 174–178. 29. Joseph R, Dickerson S, Willis R, Frankenfield D et al. Interference by nonsteroidal antiinflammatory drugs in EMIT and TDx assays for drugs of abuse. J Anal Toxicol 1995; 19: 13–17.
Chapter 4
Synthetic Urine, Flushing, Detoxifying, and Related Agents for Beating Urine Drug Tests: Are They Effective?
Abstract Searching the Internet with key words Beat + Drug Test produced over 140,000 results, indicating that many commercial products are readily available through the Internet for the purpose of invalidating urine drug testing. Fortunately, most of the products have no documented ability to invalidate drug tests and may be considered mostly as an advertising gimmick. although synthetic urine has characteristic properties of normal urine, a simple temperature check at the point of collection may provide a clue to identify such specimens. In addition, diuretics such as hydrochlorothiazide as well as various detoxifying agents may produce dilute urine where the creatinine concentration may be below an acceptable limit. Contrary to the claims of the manufacturers, these detoxifying agents and herbal pills are mostly ineffective in invalidating a urine drugs test result. Keywords Detoxifying agents · Flushing agents · Synthetic urine
1 Introduction Commercially available products to beat drug tests can be divided into two major categories: (1) products that are often taken orally to flush out unwanted drugs and toxins from the body, and (2) adulterants which are added to urine specimen after collection in order to invalidate drug testing. In addition, synthetic urine specimens are also available from various Internet sites. Synthetic urine has all normal characteristics of normal human urine and persons undergoing workplace drug testing attempt to substitute this synthetic urine as their specimen. In addition, a person may ingest diuretic medication with a hope of producing dilute urine where concentrations of abused drug or metabolite may be below the cut-off concentration of the screening assay. For example, the cut-off concentration of benzoylecgonine (metabolite of cocaine) in the immunoassay screening step is 300 ng/mL. Therefore, if the concentration of benzoylecgonine is below 300 ng/mL the specimen is considered negative. If a person has abused cocaine a few days prior to drug testing and may have a concentration just over the cut-off, and the individual drinks plenty of A. Dasgupta, Beating Drug Tests and Defending Positive Results, C Springer Science+Business Media, LLC 2010 DOI 10.1007/978-1-60761-527-9_4,
45
46
4
Synthetic Urine, Flushing, Detoxifying, and Related Agents
water and a diuretic medication or a detoxifying agents which usually contains caffeine, a diuretic, the urine specimen will be diluted, thus pushing the concentration below the screening cut-off of 300 ng/mL. If a specimen is tested negative by the immunoassays, it usually does not undergo further analysis by a more sophisticated and specific confirmation technique such as gas chromatography/mass spectrometry, and thus the individual may pass the drug test. In reality, these approaches are not very effective in beating a workplace urine drug test.
2 Synthetic Urine In general, many Internet sites appear to sell the same synthetic urine product and it costs between $31 to over $100. Quick Fix synthetic urine is available from an Internet site (http://www.ddetox.com/products_1939html) for $31.99. Another Internet site (http://detoxland.com) also sells this product for $31.99 and yet another (http://www.boxdetox.com) for $31.99. The Quick Fix container can be microwaved for 10 s for initial heating with the cap open to achieve a temperature between 94 and 100◦ F, which is the expected temperature range of normal urine after collection. A heater pad is also provided with the Quick Fix synthetic urine which should also be heated with the urine and then should be taped to the urine specimen with the cap closed. The manufacturer claims that synthetic urine can maintain the desired temperature if taped with the heating pad for up to 6 h in an inside pocket of clothing being worn. Ultra pure premixed synthetic urine is available from Detox.com (http://www.detoxshops.com) for $31.99. A 4-oz size of ultra pure synthetic urine costs $41.99, while this site also sells Quick Fix synthetic urine for $31.99. A 4-oz size of ultra pure synthetic urine is also sold for $41.99 from another Internet site which sells various products to cheat on a drug test (http://www.boxdetox.com). Tinkle brand synthetic urine is sold by the Internet site http://www.syntheticurine.com, and is a pre-mixed liquid packaged in a 2-oz plastic container along with a heat temperature strip and a hand warmer. The Internet site says that this product cannot be shipped in seven states (AK, IL, KY, OK, NJ, NC and SC). The Internet site http://www.cleartest.com/products/synthetic-urine also sells synthetic urine for $35.99. This synthetic urine is available in concentrated form and should be mixed with warm water at body temperature to produce a urine specimen that should be submitted for drug testing in order to pass a drug test. The kit comes with two vials containing synthetic urine (enough for two tests), a plastic 4-oz bottle, two hand warmers and a temperature strip. The synthetic urine should be prepared by mixing concentrated urine with warm water (including tap water) and then the temperature strip should be used to check the temperature of the specimen to ensure that it is within the acceptable limit. The manufacturer recommends that body temperature of the specimen is maintained by putting it under armpits or alternatively in pants. In addition, the manufacturer also sells a device called “Urinator” which is a small electronic device that maintains temperature of the synthetic urine specimen at body temperature for up to 4 h. This device is battery operated (two 9-V batteries) and is sold for $149.95.
4
Specimen Integrity Testing
47
Human urine specimens not containing any drugs (frozen urine or dehydrated urine) are also available for substitution purposes in order to beat a drug test. Fortunately, in many States like South Carolina, North Carolina, Nebraska, New Jersey, etc. it is illegal to sell or give away urine for the purpose of defrauding a drug test. In South Carolina one person was selling his urine for $69 per sample in order to pass the drug test. The person was arrested and found guilty by the Supreme Court of South Carolina. Unfortunately, if substituted urine specimen cannot be identified by temperature index at the collection site, there is no way to identify substituted urine by any laboratory test.
3 Composition of Synthetic Urine The composition of normal human urine varies widely from one individual to another because of the difference in fluid intake, diet, presence of any disease such as diabetes and various other factors. In general, normal human urine is composed of both organic compounds and inorganic salt. Usually urea and creatinine are the major organic compounds in urine along with uric acid. In addition, very small amounts of protein, fatty acid, hormones and a variety of other organic products are found in urine. Inorganic cations found in urine include sodium, potassium, chloride, magnesium, and calcium while inorganic anions are ammonium, sulphate and various phosphates. The pH of normal human urine may vary widely between acidic and basic. The pH of normal urine varies within the same day but should be within 4.5–8.0. The specific gravity should be between 1.005 and 1.030. The creatinine concentration of normal urine varies between 20 and 400 mg/dL. Synthetic urine mimics these values. However, certain trace macromolecules which are normally found in urine specimens may not be present in synthetic urine. There are various formulas for preparing synthetic urine for research. Mayrovitz and Sims dissolved 25 g of urea, 2 g of creatinine, 9 g of sodium chloride, 2.5 g of disodium hydrogen orthophosphate anhydrous, 3 g of ammonium chloride, and 3 g of sodium sulphite hydrated in 1 L of water to prepared synthetic urine for their study. The pH of the synthetic urine was adjusted to 7.8 [1]. In general, synthetic urine has the same specific gravity, pH and creatinine content as expected in a normal urine specimen. The color of normal urine is due to pigments known as urochromes. Artificial color can be added to synthetic urine to mimic the color of normal urine. Synthetic urine cannot be distinguished from normal urine by specimen integrity testing except for careful visual inspection.
4 Specimen Integrity Testing Both the collection site and the laboratory have a number of mechanisms to detect adulterated specimens. The temperature of urine specimen should be checked within 4 min of collection and the temperature should be between 32 and 38◦ C (90–100.4◦ F) but urine specimens may remain warmer than 33◦ C for up to 15 min.
48
4
Synthetic Urine, Flushing, Detoxifying, and Related Agents
The pH of normal urine varies within the same day but should be within 4.5–8.0. The specific gravity should be between 1.005 and 1.030. The creatinine concentration of normal urine varies between 20 and 400 mg/dL. A specimen is considered as diluted if the creatinine is
