Public Citizen Warned of Zelnorm Dangers in 2001

Source | Public Citizen

In March 2001, Public Citizen urged the U.S. 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.

Researchers at Public Citizen had also noted in the petition that receptors with which Zelnorm interacts exist not only in the intestinal tract - related to its anti-constipation effects - but also in the heart. They 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.