FDA issues warning on antifungal safety

Johnson & Johnson's antifungal drug Sporanox (itraconazole) isassociated with a small but real risk of developing congestive heart failure, according to the US Food and Drug Administration, which has issued an advisory warning that the drug has been linked to 58 reported cases of CHF and 13 deaths, although it added that the relationship was unclear. For example, 10 of the 13 patients who died had serious underlying conditions.

"Results of recent studies of Sporanox revealed a potential for the drug to weaken the force of the heart muscle's contractions," said the agency. J&J has issued letters to physicians warning of the risk and the labeling of the product will also be modified to include the potential link. The warning now states that Sporanox should not be administered for the treatment of fungal nail infections in patients with evidence of cardiac dysfunction, such as CHF, or a history of CHF.

Sporanox is one of J&J's biggest-selling drugs, with revenues of $640 million in 2000. The product's main rival is Novartis' Lamisil (terbinafine), but the agency commented that "there is insufficient data to allow the FDA to make any kind of statement about the comparative safety" of the two drugs. In fact, the agency took the opportunity presented by the CHF warning to reiterate the risks of rare liver toxicity seen with both products, which is already included on their labeling, because some cases have involved patients who had neither pre-existing liver disease nor a serious underlying medical condition.