The popular antihistamine Seldane is unsafe and should be taken off the market, the Food and Drug Administration announced Monday.
Since its introduction in 1985, the drug has been blamed for perhaps hundreds of deaths from unstable heart rhythms when taken with the common antibiotic erythromycin or with the antifungal drug ketoconozole, the FDA said. Patients with liver disease have also reported abnormal heart rhythms when taking Seldane alone.
The agency suggested that users talk with their doctors about switching from Seldane, also known as terfenadine, to another prescription antihistamine approved in July 1996, Allegra (fexofenadine). Allegra has the same beneficial effects as Seldane without any of the harmful side effects, said Robert J. Temple, director of the FDA’s Office of Drug Evaluation. Both drugs are manufactured by Hoechst Marion Roussel.
Pharmacists wrote 6.5 million prescriptions for Seldane products between January and November of last year, according to Hoechst. FDA officials said they hoped to withdraw the approval for Seldane immediately after the 30-day comment period after Monday’s announcement. The move would apply to Seldane, Seldane-D (which includes the drug psuedoephedrine) and generic versions of the drug - one of which was only approved for sale by the agency this month.
Any such action could be delayed if Hoescht fights the withdrawal, however, and company officials indicated they would do so.
“We fully intend to fight any challenge to remove Seldane and Seldane-D from the market,” said company spokesman Charles F. Rouse III. “Seldane is a safe and effective product when taken in accordance with product labeling.” At the same time, the company has kicked off a new initiative to encourage consumers switch to Allegra.
Seldane was the first anti-allergy drug approved that doesn’t make most users drowsy.
Because Seldane’s potentially dangerous interactions with other drugs have long been known, regulators and Hoechst have repeatedly issued warnings to doctors, pharmacists and patients to avoid taking the antihistamine with those other drugs.
Such warnings have caused the number of Seldane-related incidents to drop sharply over time.
But recent surveys have shown that some doctors and pharmacists have not gotten the message and continue to prescribe the potentially fatal combinations.
Also, Temple said, even if pharmacists and doctors prescribe the drug properly, consumers keep the bottle in the medicine chest and might use it whenever they feel an allergy attack coming on without regard to other drugs they might be taking at the time.
“They get some antihistamine and keep it around until they need it,” Temple said.
A consumer health advocate Monday said that the FDA and Hoechst had not acted quickly enough to take Seldane off the market.
“A responsible company would have recalled all supplies of Seldane,” said Sidney M. Wolfe, executive director of Public Citizen’s Health Research Group.
Wolfe suggested the drug should be recalled, a more drastic step that requires removing the product from stores. “The drug shouldn’t be around at all, period.”
Drug industry analyst Hemant K. Shah agreed that the timing of the FDA’s action was “very interesting. If this is a bad drug today, it was a bad drug a year ago or two years ago.”
Shah estimated Seldane sales at about $150 million a year, down sharply from a peak of some $500 million.