Handbook of antimicrobial therapy

331 Pages·2005·1 MB·English

by  Mark Abramowicz

Handbook of
Antimicrobial
Therapy
Selected Articles fromTreatment Guidelines
with updates fromThe Medical Letter®
Published by
The Medical Letter, Inc.
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New Rochelle, New York 10801-7537
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17th Edition
Copyright 2005
(ISSN 0190-3454)
(ISBN 0-9719093-3-4)
The Medical Letter Inc.
1000 Main Street
New Rochelle, New York 10801-7537
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Contents
Summary................................................................................................ 7
Pathogens in Specific Organs and Tissues.......................................... 32
Bacterial Infections
Choice of Antibacterial Drugs ............................................................. 43
Pneumonia ........................................................................................ 64
Gemifloxacin (Factive) .................................................................. 75
Telithromycin (Ketek) .................................................................... 79
Tuberculosis ..................................................................................... 85
Antimicrobial Prophylaxis for Surgery.......................................... 98
Antibacterial Prophylaxis for Dental, GI and GU Procedures .......... 109
Lyme Disease..................................................................................... 112
Fungal Infections .................................................................................. 117
Micafungin (Mycamine) for Fungal Infections ................................. 133
HIV Infection......................................................................................... 138
Two Once-Daily Fixed-Dose NRTI Combinations......................... 155
Viral Infections (Non-HIV) ................................................................. 157
Entecavir (Baraclude) for Chronic Hepatitis B Infection.............. 177
Parasitic Infections ............................................................................... 179
Sexually Transmitted Infections ......................................................... 194
Advice for Travelers ............................................................................. 209
Menactra: A Meningococcal Conjugate Vaccine .............................. 227
Rifaximin (Xifaxan) for Travelers’ Diarrhea ..................................... 232
Picaridin: A New Insect Repellent ................................................... 235
Adverse Effects of Antimicrobial Drugs............................................... 238
Dosage of Antimicrobial Drugs ............................................................. 253
Pregnancy, Safety ................................................................................. 278
Trade Names ......................................................................................... 284
Index ...................................................................................................... 304
Table Index ........................................................................................ 331
EDITOR
Mark Abramowicz, M.D.
DEPUTY EDITOR
Gianna Zuccotti, M.D., M.P.H., Weill Medical College of Cornell University
DIRECTOR OF DRUG INFORMATION
Jean-Marie Pflomm, Pharm.D.
SENIOR ASSOCIATE EDITORS
Donna Goodstein
Amy Faucard
ASSISTANT EDITOR
Cynthia Macapagal Covey
MANAGINGEDITOR
Susie Wong
PRODUCTION DESIGNER
Cheryl Brown
ADVISORY BOARD
Jules Hirsch, M.D., Rockefeller University
James D. Kenney, M.D.,Yale University School of Medicine
Richard B. Kim, M.D., Vanderbilt School of Medicine
Gerald L. Mandell, M.D., University of Virginia School of Medicine
Hans Meinertz, M.D., University Hospital, Copenhagen
Dan M. Roden, M.D., Vanderbilt School of Medicine
F. Estelle R. Simons, M.D.,University of Manitoba
Neal H. Steigbigel, M.D.,New York University School of Medicine
VP FINANCE & OPERATIONS
Yosef Wissner-Levy
Introduction
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ANTIBACTERIAL DRUGS:
A BRIEF SUMMARY FOR QUICK REFERENCE
AMINOGLYCOSIDES — Aminoglycosides are effective against
many gram-negative bacteria, but not gram-positives or anaerobes. They
are often used together with a ß-lactam antibiotic such as ampicillin,
ticarcillin, piperacillin, a cephalosporin, imipenem or aztreonam. They
may be ototoxic and nephrotoxic, especially in patients with diminished
renal function.
Amikacin (Amikin) —Amikacin is often effective for treatment of
infections caused by gram-negative strains resistant to gentamicin and
tobramycin, including some strains of Pseudomonas aeruginosa and
Acinetobacter. It is generally reserved for treatment of serious infections
caused by amikacin-susceptible gram-negative bacteria known or sus-
pected to be resistant to the other aminoglycosides. Like other amino-
glycosides, its distribution to the lungs is limited and when used to treat
gram-negative bacilli that cause pneumonia it should be combined with
another agent to which the organism is susceptible, such as a ß-lactam.
It has also been used concurrently with other drugs for treatment of
some mycobacterial infections.
Gentamicin (Garamycin, and others) — Useful for treatment of
many hospital-acquired infections caused by gram-negative bacteria.
Strains of gram-negative bacilli resistant to gentamicin are often sus-
ceptible to amikacin or to one of the third-generation cephalosporins,
cefepime, or imipenem or meropenem. Gentamicin is also used with
penicillin G, ampicillin or vancomycin for treatment of endocarditis
caused by susceptible enterococci.
Kanamycin (Kantrex, and others) — Active against some gram-
negative bacilli (except Pseudomonas or anaerobes), but most centers
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now use gentamicin, tobramycin or amikacin instead. Kanamycin can be
useful concurrently with other drugs for treatment of tuberculosis.
Neomycin— A drug that can cause severe damage to hearing and
renal function and has the same antibacterial spectrum as kanamycin.
Parenteral formulations have no rational use because of their toxicity.
Deafness has also followed topical use over large areas of skin, injection
into cavities such as joints, and oral administration, especially in patients
with renal insufficiency.
Streptomycin — Streptomycin has been displaced by gentamicin
for treatment of gram-negative infections, but it is still sometimes used
concurrently with other drugs for treatment of tuberculosis and is occa-
sionally used with penicillin, ampicillin or vancomycin to treat entero-
coccal endocarditis.
Tobramycin (Nebcin, and others) — Similar to gentamicin but
with greater activity in vitro against Pseudomonas aeruginosa and less
activity against Serratia. In clinical use, it is not certain that it is signif-
icantly less nephrotoxic than gentamicin.
AMINOSALICYLIC ACID (PAS) — Used in antituberculosis regi-
mens for many years, its distressing gastrointestinal effects caused many
patients to stop taking it prematurely. An enteric-coated oral formulation
(Paser) is more tolerable, and is used occasionally in combination with
other drugs in treating tuberculosis due to organisms resistant to first-
line drugs.
AMOXICILLIN(Amoxil, and others) — See Penicillins
AMOXICILLIN/CLAVULANIC ACID(Augmentin) — See
Penicillins
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AMPICILLIN(Principen, and others) — See Penicillins
AMPICILLIN /SULBACTAM(Unasyn) — See Penicillins
AZITHROMYCIN (Zithromax) — See Macrolides
AZTREONAM (Azactam) — A parenteral monobactam (ß-lactam)
antibiotic active against most aerobic gram-negative bacilli, including
Pseudomonas aeruginosa, but not against gram-positive organisms or
anaerobes. Aztreonam has little cross-allergenicity with penicillins and
cephalosporins.
BACITRACIN — A nephrotoxic drug used in the past to treat severe
systemic infections caused by staphylococci resistant to penicillin G. Its
use is now restricted mainly to topical application.
CAPREOMYCIN (Capastat) — A second-line antituberculosis drug.
CARBAPENEMS
Ertapenem (Invanz) — A parenteral carbapenem with a longer
half-life but narrower antibacterial spectrum than imipenem and
meropenem. It is more active against some extended-spectrum ß-lacta-
mase-producing gram-negative bacilli, but less active against gram-pos-
itive cocci, Pseudomonas aeruginosa and Acinetobacter spp. For empir-
ic treatment of intra-abdominal, pelvic and urinary tract infections and
community-acquired pneumonia, it offers no clear advantage over older
drugs.
Imipenem/Cilastatin (Primaxin) — A parenteral carbapenem ß-
lactam with an especially broad antibacterial spectrum. Cilastatin sodi-
um inhibits renal tubular metabolism of imipenem. This combination
may be especially useful for treatment of serious infections in which aer-
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obic gram-negative bacilli, anaerobes, and Staphylococcus aureus (but
not oxacillin-resistant strains)might all be involved. It is active against
many gram-negative bacilli that are resistant to third- and fourth-gener-
ation cephalosporins, aztreonam and aminoglycosides. Resistance to
imipenem in Pseudomonas aeruginosa occasionally develops during
therapy.
Meropenem (Merrem) —A carbapenem for parenteral use similar
to imipenem/cilastatin. It may have less potential than imipenem for
causing seizures.
CARBENICILLIN — See Penicillins
CEPHALOSPORINS — All cephalosporins except ceftazidime have
good activity against most gram-positive cocci, and all cephalosporins
are active against many strains of gram-negative bacilli. All
cephalosporins are inactive against enterococci and oxacillin-resistant
staphylococci. These drugs are often prescribed for patients allergic to
penicillin, but such patients may also have allergic reactions to
cephalosporins. Rare, potentially fatal immune-mediated hemolysis has
been reported, particularly with ceftriaxone and cefotetan.
The cephalosporins can be classified into four ‘‘generations’’based on
their activity against gram-negative organisms. All first-generation drugs
have a similar spectrum, including many gram-positive cocci (but not
enterococci or oxacillin-resistant Staphylococcus aureus), Escherichia
coli, Klebsiella pneumoniae, and Proteus mirabilis. Among the first-
generation parenteral cephalosporins, cefazolin (Ancef, and others) is
less painful on intramuscular injection than cephapirin (Cefadyl, and
others). The first-generation parenteral cephalosporins are usually given
intravenously, and cefazolin is most frequently used because of its
longer half-life.
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