Expanded Warnings For J&J's Hismanal

Johnson & Johnson is expanding the warning label on its antihistamineHismanal (astemizole) to extend the list of medicines with which it should not be taken, and give more information about cardiovascular adverse events and rare reports of anaphylaxis.

"Hismanal is associated with risks of death due to irregular heart rhythms when taken with certain other drugs and when used at higher than the recommended labeled dose," according to the Food and Drug Administration.

The new warning follows the removal from the market of another antihistamine, Hoechst Marion Roussel's Seldane (terfenadine) last year. HMR has since replaced Seldane with a newer drug, Allegra (fexofenadine), but J&J's follow-up norastemizole (licensed on February 4 from Sepracor, which also developed fexofenadine) is still years off the US market. J&J notes that the FDA has not raised the issue of withdrawing the drug, and believes it is safe and effective for some patients. Hismanal is thought to account for only 3% of the prescription antihistamine market.