March 30, 2007
FDA Should Not Have Approved Tegaserod (Zelnorm); Public Citizen Warned of Dangers When Drug Was Considered in 2001
Statement of Sidney Wolfe, MD, director of Public Citizen’s Health Research Group
In March 2001, we urged the Food and Drug Administration (FDA) not to approve tegaserod (Zelnorm) because it was only marginally effective in treating constipation-predominant diarrhea in patients with irritable bowel syndrome and because of serious safety concerns. These included an increased incidence of ovarian cysts and a five-fold increase in fainting compared to placebo in patients in clinical trials completed before its approval. (Visit Public Citizen’s 2001 petition to the FDA by clicking here.)
We noted in the petition that receptors with which this drug interacts exist not only in the intestinal tract – related to its anti-constipation effects – but also in the heart. We pointed out that cisapride, a gastrointestinal drug which also caused fainting and was taken off the market because of cardiac arrhythmias, also affected this same receptor in the heart.
In 2004, we warned readers of our Worst Pills, Best Pills newsletter not to take Zelnorm because of the dangers involved. There were 2.13 million prescriptions issued for Zelnorm in 2005 alone, making it one of the top 200 drugs in the country.
Despite our warnings, the FDA approved a drug with marginal effectiveness in the face of serious questions about its safety – putting at risk the millions of people who have already used it. Today the FDA has asked the company to withdraw the drug from the market only after even clearer evidence of harm. This again raises questions about both the adequacy of the FDA’s pre-approval review and post-marketing surveillance.