Regulators said roughly a dozen manufacturers and distributors have until May 9 to cease sales of rectal suppositories containing the drug. The move does not affect several trimethobenzamide-containing oral drugs and injection drugs also used for nausea and vomiting.
About 2 million suppositories containing trimethobenzamide were sold last year, according to FDA.
The ban affects widely distributed brands including Tigan, Tegamide, Trimethobenz, and Trimazide.
Patients taking any of those brands should talk with their doctors, says Jason Woo, MD, associate director of scientific and medical affairs in the FDA’s Office of Compliance. Officials said they had no safety concerns but that manufacturers had not shown substantial evidence that trimethobenzamide is effective in suppository form.
“[Patients] should discuss the alternatives. There are approved suppository products that are on the market,” he says.
Trimethobenzamide is one of hundreds of drugs circulating in the U.S. despite never gaining FDA approval. A 1962 law forcing companies to prove a drug’s effectiveness before selling it exempted products on the market before that year.
The FDA first determined in 1979 that companies never proved trimethobenzamide suppositories are effective. But in June 2006, the agency began a crackdown on unapproved drugs.
Deborah M. Autor, director of the FDA’s Office of Compliance, acknowledged that trimethobenzamide has remained unhindered for a long time.
“I think there are probably several hundred unapproved prescription drugs out there,” Autor says. “We think it’s important to get the word out to the industry.”
Any company wishing to continue selling trimethobenzamide suppository after May 9 must go through the FDA’s full approval process, says Michael Levy, director of the agency’s New Drugs and Labeling Compliance division.
Those that don’t “will then be subject to immediate enforcement action such as seizure and injunction,” he says.