The FDA has required the manufacturer of the secondgeneration antipsychotic quetiapine (Seroquel) to add a warning to the labeling saying that use of the drug should be avoided in combination with other drugs that prolong the electrocardiographic QTc interval (Table 1). The warning is based only on postmarketing reports of QT-interval prolongation in patients who overdosed on the drug, had concomitant illness, or were taking other drugs known to cause electrolyte imbalances or increase the QT interval. QT prolongation can lead to torsades de pointes, a potentially fatal cardiac...

Dirithromycin (Dynabac - manufactured by Lilly, distributed by Bock), an oral macrolide antibiotic chemically similar to erythromycin, clarithromycin (Biaxin) and azithromycin (Zithromax), has been approved for marketing by the US Food and Drug Administration (FDA).

Grepafloxacin (Raxar - Glaxo Wellcome), a once-daily oral fluoroquinolone, is now being marketed for treatment of community-acquired pneumonia, acute bacterial exacerbations of chronic bronchitis, uncomplicated gonorrhea, and nongonococcal urethritis and cervicitis.

Augmentin XR (GlaxoSmithKline), an oral extended-release combination of amoxicillin and the beta-lactamase inhibitor clavulanic acid, is now being promoted for treatment of acute bacterial sinusitis and community-acquired pneumonia. Augmentin XR contains a higher dose of amoxicillin than Augmentin.

The FDA has announced changes in the labeling of simvastatin to reduce the risk of myopathy. These changes include limiting the use of the 80-mg maximum dose to patients who have been taking it for 12 months or more without evidence of myopathy and new recommendations for use of simvastatin with other drugs. Simvastatin is available alone (Zocor, and others) and in combination with ezetimibe (Vytorin) and with niacin (Simcor).

Loracarbef (Lorabid - Lilly), a new beta-lactam antibiotic with antimicrobial activity similar to the second-generation cephalosporins, has been approved by the US Food and Drug Administration for treatment of respiratory, skin, and urinary tract infection caused by susceptible organisms in both adults and children. It will probably compete with drugs such as trimethoprim-sulfamethoxazole (Bactrim, Septra, and others), amoxicillin-clavulanic acid (Augmentin), cefaclor (Ceclor), cefuroxime axetil (Ceftin), and cefprozil (Cefzil - Medical Letter, 34:63,...

Clarithromycin (Biaxin - Abbott) and azithromycin (Zithromax - Pfizer), two macrolide antibiotics chemically related to erythromycin, have been approved by the US Food and Drug Administration for treatment of respiratory, skin, and skin structure infections. Azithromycin has also been approved for treatment of nongonococcal urethritis and cervicitis caused by Chlamydia trachomatis.

Sparfloxacin (Zagam - Rh ne-Poulenc Rorer) and levofloxacin (Levaquin - Ortho-McNeil) are the newest fluoroquinolone antimicrobials to be approved by the US Food and Drug Administration. Sparfloxacin in a once-daily oral preparation is being marketed for treatment of community-acquired pneumonia and acute bacterial exacerbations of chronic bronchitis. Levofloxacin, which is the active stereoisomer of ofloxacin (Floxin), is available for either oral or parenteral use; it is approved for oncedaily treatment of community-acquired pneumonia, acute exacerbations of chronic bronchitis,...

Cefdinir (Omnicef - Parke-Davis), a third-generation oral cephalosporin, has been approved by the FDA for treatment of acute sinusitis, otitis media, acute exacerbations of chronic bronchitis, pharyngitis, community-acquired pneumonia and skin infections. Other drugs available for these indications are reviewed in The Medical Letter Handbook of Antimicrobial Therapy, 1998.

Gatifloxacin and moxifloxacin are now available for once-daily treatment of patients with community-acquired pneumonia, acute bacterial exacerbations of chronic bronchitis, or acute sinusitis.