A Medical Letter reader has asked us to review the safety of the fluoroquinolone antibiotic levofloxacin (Levaquin – Ortho-McNeil-Janssen), which has just been approved for generic use by the FDA and has been at the center of some recent lawsuits regarding the adequacy of its safety warnings.

Piperacillin/tazobactam (Zosyn - Lederle), an antibiotic combination product, has been approved by the US Food and Drug Administration for intravenous treatment of intra-abdominal, pelvic, skin, and skin-structure infections and for community-acquired pneumonia of moderate severity.

A topical formulation of 0.75% metronidazole gel (MetroGel - Curatek), an antibacterial, antiparasitic agent, was recently approved by the US Food and Drug Administration for treatment of rosacea.

Telithromycin (Ketek - Aventis) has been approved by the FDA for oral treatment of mild to moderate community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute bacterial sinusitis in patients age 18 and older. The drug is the first in a new class of antibiotics, the ketolides, derived from the macrolide erythromycin. Telithromycin has been marketed in Europe since 2001.

Doripenem (Doribax - Ortho-McNeil Janssen), an intravenous (IV) carbapenem antibiotic with a spectrum of activity similar to that of imipenem and meropenem, has been approved by the FDA for treatment of complicated intra-abdominal and urinary tract infections. Use of doripenem for treatment of nosocomial pneumonia, including ventilator-associated pneumonia, is still under FDA review.

Ertapenem (er ta pen' em; Invanz - Merck), a carbapenem antibacterial with a narrower spectrum of activity than imipenem (Primaxin) or meropenem (Merrem), has been approved by the FDA for once-daily IV treatment of complicated intra-abdominal, urinary tract and skin and skin structure infections, acute pelvic infections, and community-acquired pneumonia.

Azelaic acid, a naturally occurring heptanedicarboxylic acid, has been marketed in the USA as a 20% cream (Azelex - Allergan) for treatment of acne. The drug has been available in Europe for several years.

Tigecycline (Tygacil - Wyeth), a derivative of minocycline, is a new intravenous (IV) antibiotic approved for treatment of complicated intra-abdominal and skin and skin-structure infections.

The FDA has announced that it is requiring changes in the labeling of the macrolide antibiotic azithromycin (Zithromax, Zmax) to warn about the risk of QT prolongation and cardiac arrhythmias.1 The new warnings are based on a retrospective study in The New England Journal of Medicine (reviewed previously in The Medical Letter2), which found that among patients who received 347,795 prescriptions for azithromycin, there were 29 cardiovascular deaths, a significantly higher rate than the 42 that occurred among patients who received 1,348,672 prescriptions for amoxicillin (which does not prolong...

The gram-positive bacillus Clostridium difficile is the most common identifiable cause of antibiotic-associated diarrhea and pseudomembranous colitis (R Fekety in GL Mandell et al, eds, Principles and Practice of Infectious Diseases, 3rd ed, New York:Churchill Livingstone, 1990, page 863). C. difficile colitis usually develops during or soon after antibiotic treatment. Virtually any antimicrobial agent can cause the disorder, but clindamycin, ampicillin and the cephalosporins have been implicated most frequently. Pseudomembranous colitis was recently reported in five patients who had ...