Clinician's Handbook of Prescription Drugs

CLINICIAN’S HANDBOOK OF PRESCRIPTION DRUGS

Seymour Ehrenpreis, PhD Former Chairman and Professor Emeritus of Pharmacology Chicago Medical School Chicago, IL

Eli D. Ehrenpreis, MD Department of Gastroenterology University of Chicago Chicago, IL

McGRAW-HILL Medical Publishing Division New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto

Notice Medicine is an ever-changing science. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required. The authors and the publisher of this work have checked with sources believed to be reliable in their efforts to provide information that is complete and generally in accord with the standards accepted at the time of publication. However, in view of the possibility of human error or changes in medical sciences, neither the authors nor the publisher nor any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete, and they disclaim all responsibility for any errors or omissions or for the results obtained from use of the information contained in this work. Readers are encouraged to confirm the information contained herein with other sources. For example and in particular, readers are advised to check the product information sheet included in the package of each drug they plan to administer to be certain that the information contained in this work is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. This recommendation is of particular importance in connection with new or infrequently used drugs.

McGraw-Hill A Division of The McGraw-Hill Companies Clinician’s Handbook of Prescription Drugs Copyright © 2001 by The McGraw-Hill Companies, Inc. All rights reserved. Printed in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of the publisher. 1 2 3 4 5 6 7 8 9 0

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ISBN 0-07-134385-7

This book was set in QuarkXPress by Software Services. The editors were Andrea Seils and Barbara Holton. The production manager was Clare Stanley. The cover designer was Elizabeth Schmitz. R. R. Donnelley & Sons was printer and binder. This book is printed on acid-free paper. Library of Congress Cataloging-in-Publication Data

Ehrenpreis, Seymour. Clinician’s handbook of prescription drugs/Seymour Ehrenpreis, Eli Ehrenpreis. p.; cm. Includes bibliographical references and index. ISBN 0-07-134385-7 1. Drugs—Handbooks, manuals, etc. I. Ehrenpreis, Eli. II. Title. [DNLM: 1. Pharmaceutical Preparations—Handbooks. QV 39 E33c 2001] RM301.12.E37 2001 615’.1—dc21 2001030501

ADVISORY BOARD Richard Albach, Ph.D. Professor, Department of Microbiology and Immunology, Chicago Medical School, North Chicago, Illinois Jean-Lue Benoit, M.D. Assistant Professor of Medicine, Infectious Disease Division, University of Chicago, Chicago, Illinois. Martin Burke, M.D. Assistant Professor of Clinical Medicine, Cardiology Division, University of Chicago, Chicago, Illinois Dennis Citrin, M.D. Associate Professor, Department of Medicine, Northwestern University Medical School, Chicago, Illinois Mark D. Ehrenpreis, M.D. Associate Professor, Department of Urology, New York Medical College, Valhalla, New York Thomas Faust, M.D. Assistant Professor of Clinical Medicine, Hepatology Division, University of Chicago, Chicago, Illinois Daniel Fintel, M.D. Associate Professor, Department of Medicine, Director, Critical Care, Northwestern University School of Medicine, Chicago, Illinois Eric Gall, M.D. Professor and Chairman, Department of Medicine, Chicago Medical School, North Chicago, Illinois Phillip C. Hoffman, M.D. Professor of Clinical Medicine, Hematology/Oncology Division, University of Chicago, Chicago, Illinois Nelson Kanter, M.D. Associate Professor of Clinical Medicine, Pulmonary/Critical Care Division, University of Chicago, Chicago, Illiniois

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ADVISORY BOARD

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Robert S. Lauren, DDS DDS Associates Limited, Skokie, Illinois Gerald B. Leiken, M.D. Director, Medical Emergency Services, Rush Medical Center, Chicago, Illinois Michael Marshall, M.S. Physician’s Assistant, United States Army, Seattle, Washington Lawrence Perlmuter, Ph.D. Professor, Department of Clinical Psychology, Chicago Medical School, North Chicago, Illinois Raymond Quock, Ph.D. Professor and Chairman, Department of Pharmaceutical Sciences, Washington State University, Pullman, Washington Sant Singh, M.D. Professor, Department of Medicine, Chief, Endocrinology, Chicago Medical School, North Chicago, Illinois Daniel Zaitman, M.D. Chicago Medical School, North Chicago, Illinois

PREFACE A recent article published in the New York Times quoted the astounding statistic that as many as 7,000–10,000 deaths in the United States can be attributed on an annual basis to prescription errors. Countless hospital days, loss of productivity, and an atmosphere of distrust of modern medicine all result from such errors. Many causes can be found for these mistakes; drugs with completely different properties, uses, and toxicity profiles may have similar names. Polypharmacy, a common phenomenon in the elderly, places patients at risk for complex drug–drug interactions. Difficulty with high-volume record keeping and the loss of personal interaction with the “family pharmacist” certainly result in more patients receiving the wrong medication or dosage when a prescription is filled. Finally, the rapid pace of modern medical practices coupled with the ever–bewildering numbers of medications on the market result in a situation in which the busy practitioner may have difficulty keeping abreast of important aspects of the drugs they are prescribing. It was with these concerns in mind that we undertook the task of writing a manual of drug prescription for the practicing clinician. No one can be expected to commit to memory everything important about all the drugs available on the market. It can be quite time consuming and frustrating to search for important information on individual entries in a large comprehensive volume such as the Physician’s Desk Reference. Thus, our main objective in creating this book was to provide the most essential information on all commonly prescribed drugs in a concise, accurate and easy-to-read manner. In producing this book, it is our hope that we can help clinicians give the best care possible to patients taking prescription drugs. We believe this book will benefit you in looking up drugs that are not frequently prescribed. In addition, you will have an opportunity to reacquaint yourself with details about familiar drugs when using this book “at the bedside.”

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PREFACE

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The book does not have complete entries for all prescription drugs. Some have been left out simply because of lack of sufficient available information or because of very limited use. In addition, we have not included many drug combinations because of space considerations. Furthermore, we have restricted our discussion in the case of drugs that are members of the same drug class. Most if not all of the drugs in a particular pharmacologic class have similar if not identical characteristics, for example, side effects, drug–drug interactions, contraindications. Accordingly, we have selected one or more drugs to serve as prototypes and these have been given a complete entry (as described below). For other members of the particular class, we have presented only essential information, referring the reader in each case to the prototype for additional details. On the other hand, we have discussed in full a number of widely used drugs that for one reason or another are not listed in the Physician’s Drug Reference 2000 or for which only the drug name is stated without any details. In other instances, we provide even more complete information than offered by the manufacturer. For example, no drug–drug interactions are listed by the manufacturers for benzodiazepines in the Physician’s Desk Reference, whereas we list a number of these interactions that are clinically important. The reader should note that some information provided may differ from that contained in the manufacturer’s package insert. The decision to include or exclude information is based on our best judgment or on the advice of our Advisory Board after reviewing all available data. A handbook such as this, with its emphasis on conciseness, can present only a relatively small fraction of the total knowledge available about any particular drug. Thus, it is our considered opinion that the clinician attempt to review available product information sheets as approved by the Food and Drug Administration should the need arise to expand on the information presented herein. We strongly believe that accessing the information provided with the easy-to-follow format we have created for this manual will make this book an important reference for clinicians in a wide variety of settings. If, overall, we are able to assist the

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health care provider to administer medications to their patients safely and effectively and thereby to treat their ailments as well as prevent complications of drug therapy, we will have achieved our desired goals. The following format is used for all drugs: Brand name: For drugs that have multiple brand names, we have listed those drugs that are widely prescribed. Mechanism of action: This is stated succinctly, using at most one or two lines. Indications/dosage/route: All approved indications are listed; occasionally, widely used unapproved indications are mentioned. For the most part, dosages recommended by the manufacturer are listed. Dosages are mainly the usual adult dose (persons 1 h

Food: Given before meals and just before bedtime for asthma. Pregnancy: Category B. Lactation: No data available. Best to avoid.

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ACETYLCYSTEINE

Contraindications: As mucolytic agent: hypersensitivity to acetylcysteine. Warnings/precautions • As antidote for acetaminophen poisoning: Administer as quickly as possible. Most useful if given within 12 hours of ingestion of acetaminophen. • As inhaled drug: may induce bronchospasm. If this occurs, administer bronchodilator; suction bronchial secretions if they develop after inhalation. • Elderly: May have reduced cough reflex and therefore reduced ability to clear airway of liquefied mucus. May need concomitant suction. • For patient with asthma or hyperactive airway disease, a bronchodilator should be administered before acetylcysteine. Advice to patient: Rinse mouth out and wash face after treatment to remove adhering drug. Adverse reactions • Common: vomiting, olfactory disturbance. • Serious: bronchospasm (especially in asthmatics), hypotension. Clinically important drug interactions: None. Parameters to monitor • As antidote for acetaminophen poisoning: Monitor acetaminophen plasma levels, liver enzymes, bilirubin. Monitor for nausea, vomiting, skin rash. Acetaminophen levels: Determine at least 4 hours after acetaminophen ingestion. Administer acetylcysteine if acetaminophen level is >150 mg/mL 12 hours after ingestion. Hepatotoxicity occurs if peak level is >200 mg/mL. Monitor cardiac function, renal function, prothrombin time. Administer fresh-frozen plasma or vitamin K if prothrombin time >3 seconds compared with control. • As mucolytic agent: Monitor respiratory function for respiratory fluid increases, amount and consistency of secretions before and after treatment. Apply suction or endotrachial aspiration if necessary. Signs and symptoms of bronchospasm: if this occurs, administer bronchodilator or discontinue if necessary.

ACYCLOVIR 7

Acyclovir Brand name: Zovirax. Class of drug: Antiviral agent. Mechanism of action: Nucleotide analog; inhibits viral replication by termination of viral DNA chain and inhibition and inactivation of viral DNA polymerase. Indications/dosage/route: Oral, IV. • Herpes simplex (HSV-1 and HSV-2) infections (immunocompromised host) – Adults, children >12 years: IV 5 mg/kg (infuse at constant rate over 1 hour), q8h for 7 days. – Children 12 years: PO 200 mg q4h, five doses/day; 10 days for initial therapy. Dose for 5 days for intermittent recurrent disease. Administer up to 12 months for chronic disease (suppressive therapy). – Children 12 years: IV 10 mg/kg (infuse at constant rate over 1 hour), q8h for 10 days. – Children, 6 months to 12 years: IV 500 mg/m2 (infuse at constant rate over 1 hour), q8h for 10 days. • Herpes zoster – Adults, children >12 years: PO 80 mg, q4h, five doses/day, 7–10 days. – Children 40 kg: PO 800 mg, q.i.d. 5 days. – Children >2 years: PO 20 mg/kg q.i.d. (maximum 800 mg), 5 days.

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ACYCLOVIR

Adjustment of dosage • Kidney disease: Creatinine clearance 25–50 mL/min: dose q12h; creatinine clearance 10–25 mL/min: dose q24h; creatinine clearance 12 years: 200 µg q4–6h. • Prophylaxis of exercise-induced bronchospasm – Adults, children >12 years: 200 µg 15 minutes before exercise. • Bronchodilation: syrup – Adults, children >14 years: 2–4 mg t.i.d. to q.i.d. – Children 2–6 years: Initial: 2–4 mg, Maximum: 8 mg t.i.d. to q.i.d. – Children 6–12 years: 4 mg q12h. Maximum: 12 mg q12h. – Elderly: Initial: 2 mg t.i.d. to q.i.d. Increase dose if needed to maximum of 8 mg t.i.d. to q.i.d. • Bronchodilation: extended-release tablets

ALBUTEROL

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– Adults, children >12 years: 4–8 mg q12h. Maximum: 32 mg/d. Adjustment of dosage • Kidney disease: None. • Liver disease: None. • Elderly: See above. • Pediatric: See above. Onset of Action 13 years: 125 or 250 mg q12h for 7–10 days. – Children 13 years: 1000 mg as a single dose. • Early Lyme disease (alternative treatment, doxycycline is first line) – 500 mg/d for 20 days. Cefuroxime suspension

• Pharyngitis, tonsillitis – Children 3 months–12 years: 20 mg/kg/d in 2 divided doses. Maximum: 500-mg total dose/d, for 10 days. • Acute otitis media, impetigo – Children 3 months–12 years: 30 mg/kg/d in 2 divided doses. Maximum: 1000-mg total dose/d, for 10 days. Cefuroxime sodium

• UTI, uncomplicated pneumonia, disseminated gonococcal, skin and skin structure infections – Adults: IV, IM 750 mg q8h. – Children >3 months: IV, IM 50–100 mg/kg/d in divided doses q6–8h (not to exceed adult dose of severe infections).

184 CEFUROXIME

• Severe complicated infections, bone and joint infections – Adults: IV, IM 1.5 g q8h. – Children >3 months: IV 150 mg/kg/d in divided doses q8h (not to exceed adult dose). • Life-threatening infections – Adults: IV, IM 1.5 g q6h. • Bacterial meningitis – Adults: IV, IM 1–3 g q8h. – Children >3 months: Initial: IV 200–240 mg/kg in divided doses q6–8h, then 100 mg/kg/d. • Gonorrhea (uncomplicated) – Adults: IM 1.5 g, single dose, two different sites along with 1 g probenecid PO. • Prophylaxis in surgery – Adults: IV 1.5 g 30–60 min before surgery. • Open heart surgery, prophylaxis – Adults: IV 1.5 g at initiation of anesthesia, then 1.5 g q12h. Total: 6 g. Adjustment of dosage • Kidney disease: Creatinine clearance l0 mL/min: 750 mg q24h. • Liver disease: None. • Elderly: None. • Pediatric: See above. Food: Take with yogurt or buttermilk (4 oz/d) to maintain bacterial flora and reduce the possibility of severe GI effects. Pregnancy: Category B. Lactation: Appears in breast milk. American Academy of Pediatrics considers cephalosporins to be compatible with breastfeeding. Contraindications: Hypersensitivity to other cephalosporins or related antibiotics, eg, penicillin. Warnings/precautions • Use with caution in patients with the following condition: kidney disease.

CEFUROXIME 185

• It is recommended to continue therapy for at least 2–3 days after symptoms are no longer present. For group A beta-hemolytic streptococcal infections, therapy should be continued for 10 days. • Before use, determine if patient had previous hypersensitivity reaction to cephalosporins or penicillins. Incidence of crosssensitivity to penicillins is 1–16%. A negative response to penicillin does not preclude allergic reaction to a cephalosporin. Advice to patient: Allow at least 1 hour between taking this medication and a bacteriostatic antibiotic, eg, tetracycline or amphenicol. Adverse reactions • Common: None. • Serious: hepatotoxicity, nephrotoxicity, pseudomembranous colitis, hypersensitivity reactions, bone marrow suppression. Clinically important drug interactions • Drug that increases effects/toxicity of cefuroxime: probenecid. • Cefuroxime increase effects/toxicity of following drugs: aminoglycosides, loop diuretics. Parameters to monitor • CBC with differential and platelets, serum BUN and creatinine, liver enzymes. • Temperature for sign of drug-induced persistent fever. • Signs and symptoms of antibiotic-induced bacterial or fungal superinfection. • Signs and symptoms of renal toxicity. • Signs and symptoms of fluid retention, particularly in patients receiving sodium salts of cephalosporins. Editorial comments • Cefuroxime axetil is the best oral second-generation cephalosporin for treatment of otitis media, sinusitis, COPD exacerbation, and streptococcal pharyngitis. • The oral second-generation cephalosporins are also effective in skin, soft tissue, and urinary tract infections, but other antibiotics are more cost effective.

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• IV cefuroxime is effective in meningitis caused by Hemophilus influenzae and Neisseria meningitidis. In children, however, ceftriaxone is superior to cefuroxime in the treatment of H. influenzae meningitis.

Celecoxib Brand name: Celebrex. Class of drug: Antiinflammatory, analgesic, COX-2 inhibitor. Mechanism of action: Selective inhibitor of COX-2, the enzyme required for synthesis of prostaglandins and other products of the arachidonic acid cascade. Indications/dosage/route: Oral only. • Osteoarthritis – Adults: 100 mg b.i.d. or 200 mg as single dose. • Rheumatoid arthritis – Adults: 100–200 mg b.i.d. Adjustment of dosage • Kidney disease: None. Potentially toxic to kidney. • Liver disease: Reduce dosage. Monitor carefully. • Elderly: Use lowest recommended dose. • Pediatric: Safety and efficacy have not been determined in children 15 years – Adults: 500 mg q12h. • Streptococcal pharyngitis, skin and skin structure infections – Children >1 year: Divide total daily dose and give q12h. Adjustment of dosage • Kidney disease: Creatinine clearance 50–80 mL/min: 2 g q6h; creatinine clearance 25–50 mL/min: 1.5 g q6h; creatinine clearance l0–25 mL/min: 1 g q6h; creatinine clearance 2–10 mL/min: 0.5 g q6h; creatinine clearance >2 mL/min: 0.5 g q8h. • Liver disease: None. • Elderly: None. • Pediatric: See above. Food: Take on empty stomach unless drug causes gastric distress. Consume yogurt or buttermilk (4 oz/d) to maintain bacterial flora and reduce the possibility of severe GI effects. Pregnancy: Category B.

CEPHALEXIN 189

Lactation: Appears in breast milk. American Academy of Pediatrics considers cephalosporins to be compatible with breastfeeding. Contraindications: Hypersensitivity to other cephalosporins or related antibiotics, eg, penicillin. Warnings/precautions • Use with caution in patients with the following condition: kidney disease. • It is recommended to continue therapy for at least 2–3 days after symptoms are no longer present. For group A beta-hemolytic streptococcal infections, therapy should be continued for 10 days. • Before use, determine if patient had previous hypersensitivity reaction to cephalosporins or penicillins. Incidence of crosssensitivity to penicillins is 1–16%. A negative response to penicillin does not preclude allergic reaction to a cephalosporin. Advice to patient: Allow at least 1 hour between taking this medication and a bacteriostatic antibiotic, eg, tetracycline or amphenicol. Adverse reactions • Common: None. • Serious: pseudomembranous colitis, hypersensitivity reactions, bone marrow suppression, hepatitis. Clinically important drug interactions: Probenecid increases effects/toxicity of cephalexin. Parameters to monitor • CBC with differential and platelets, liver enzymes. • Temperature for sign of drug-induced persistent fever. • Signs and symptoms of antibiotic-induced bacterial or fungal superinfection. • Signs and symptoms of renal toxicity. • Signs and symptoms of fluid retention, particularly in patients receiving sodium salts of cephalosporins. Editorial comments • Oral cephalosporins are used for Staphylococcus aureus and streptococcal infection, when penicillins are to be avoided. Common uses are cellulitis, other infections of the skin,

190 CEPHALOTHIN

osteomyelitis, streptococcal pharyngitis. They should not be used for sinusitis, otitis media, or lower respiratory infections because of poor coverage of Streptococcus pneumoniae, Moraxella catarrhalis, and Hemophilus influenzae. They are not suitable coverage for bite wounds as they do not cover Pasteurella multocida. • Cephalexin uses are similar to those of cefadroxil.

Cephalothin Brand name: Keflin. Class of drug: Cephalosporin, first generation, parenteral. Mechanism of action: Binds to penicillin-binding proteins and disrupts or inhibits bacterial cell wall synthesis. Susceptible organisms in vivo • Very effective against staphylococci and streptococci, potentially active against Streptococcus pneumoniae, active against enterococci. Not effective against MRSA. • Gram-negative spectrum is limited to community-acquired Escherichia coli, Moraxella catarrhalis, indole-negative Proteus mirabilis, and some Klebsiella pneumoniae. Not useful for nosocomial gram-negative oral anaerobes. Indications/dosage/route: IV, IM. • Serious respiratory, GU, GI, skin and soft tissue, bone, and joint infections, septicemia, endocarditis – Adults: IV, IM 500 mg–1 g q4–6h. Life-threatening infections: ≤2 g q4h. Adjustment of dosage • Kidney disease: Creatinine clearance less than 80 mL/min: usual adult dose; creatinine clearance 50–80 mL/min: ≤2 g q6h; creatinine clearance 25–50 mL/min: up to 1.5 g q6h; creatinine clearance 10–25 mL/min: up to 1 g q6h; creatinine clearance 2–10 mL/min: ≤ 500 mg q6h; creatinine clearance 6 years: 5–10 mg/d. – Children 2–5 years: 2.5 mg/d. Maximum: 5 mg/d. Adjustment of dosage • Kidney disease: Creatinine clearance