July 23, 2001Group calls for more safety studies of Zelnorm
A consumer advocacy group says that a constipation drug currently under review by the Food and Drug Administration should not be approved until lingering concerns about its safety are answered. In a letter to the agency, Public Citizen said that further studies are needed about the link between the irritable bowel syndrome drug Zelnorm and an increased risk of ovarian cysts.According to a study presented at a meeting of the FDA’s Zelnorm advisory committee, eight women taking part in clinical trials for Zelnorm developed ovarian cysts, five of whom required hospitalization and surgery. Officials with the FDA estimated that the risk of ovarian cysts among Zelnorm users was approximately three times that of women who were given a placebo.
In its letter to the FDA, Public Citizen accused the manufacturer of Zelnorm, Novartis Pharmaceuticals, of not adequately monitoring patients in its clinical trials for ovarian cysts. The group says that even though this would provide reviewers with a better understanding of the link between Zelnorm and ovarian cysts, Novartis is hesitant to use ultrasound monitoring because it could derail its efforts to have Zelnorm approved by the FDA.
“[Novartis] knows that if they have to use the ultrasound to monitor women, evidence might accumulate that [Zelnorm] does indeed induce ovarian cysts, and this they do not want to happen as it might doom their drug,” Public Citizen says. “Ultrasound monitoring in a properly designed clinical setting, however, is the only way to settle this important issue. [Zelnorm] is a drug that is, at best, minimally effective and that may be causing substantial harm.”