Medication safety labeling updates and new warnings, August 2008

FDA has issued an alert to healthcare professionals detailing the potential for serious and sometimes fatal hypersensitivity reactions in abacavir-treated patients who are positive for the human leukocyte antigene allele HLA-B*5701. This hypersensitivity reaction can include fever, rash, gastrointestinal symptoms, respiratory symptoms, and constitutional symptoms. All patients should be screened for the presence of this allele before initiation of treatment with abacavir (Ziagen, GlaxoSmithKline) or abacavir-containing agents (Epzicom, GlaxoSmithKline; Trizivir; GlaxoSmithKline). In patients with this allele, treatment with abacavir or abacavir-containing agents should be used only when the potential benefit clearly outweighs the risk.

FDA has requested that a boxed warning regarding an increased risk of tendinitis and tendon rupture be added to the product labeling for all fluoroquinolone antimicrobial drugs for systemic use. Affected products include ciprofloxacin (Cipro, Bayer; generic ciprofloxacin), ciprofloxacin extended-release (Cipro XR, Bayer; Proquin XR, Depomed), gemifloxacin (Factive, Oscient), levofloxacin (Levaquin, Ortho-McNeil), moxifloxacin (Avelox, Bayer), norfloxacin (Noroxin, Merck), and ofloxacin (Floxin, Ortho-McNeil; generic ofloxacin).