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,...

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

View the Expanded Table: Statins

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.

Fexofenadine (fex oh fen' a deen) hydrochloride (Allegra - Hoechst Marion Roussel) has been approved by the US Food and Drug Administration for treatment of seasonal allergic rhinitis. An active metabolite of terfenadine, fexofenadine is being heavily advertised as "nonsedating...without 'black box' warnings."

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.

Sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra, Staxyn) have become the standard treatment for erectile dysfunction. Head-to-head comparisons of these agents are still lacking, but some differences between them and new recommendations for their dosing (see Table 2) are worth noting.

The FDA has announced that it is requiring changes in the labeling of systemic fluoroquinolones to warn that the risk of serious adverse effects, including tendinitis, peripheral neuropathy and CNS effects, generally outweighs their benefit for the treatment of acute sinusitis, acute exacerbations of chronic bronchitis, and uncomplicated urinary tract infections. For these infections, the new labels will recommend reserving fluoroquinolones for patients with no other treatment options.

The potassium-competitive acid blocker vonoprazan (Voquezna – Phathom), which was approved earlier for treatment of erosive esophagitis, has now been approved by the FDA for relief of heartburn associated with nonerosive gastroesophageal reflux disease (GERD) in adults. Vonoprazan is also available copackaged with amoxicillin (Voquezna Dual Pak) and with amoxicillin and clarithromycin (Voquezna Triple Pak) for treatment of Helicobacter pylori infection.

Dronedarone (Multaq - Sanofi-Aventis) has been approved by the FDA for oral treatment of atrial fibrillation and flutter. Amiodarone (Cordarone, and others) is the most effective drug for this indication, but has considerable toxicity.