The drug, tegaserod (called Zelmac by its maker, Novartis Pharmaceuticals) is designed to treat constipation-predominant Irritable Bowel Syndrome (IBS). However, the drug was associated with a three- fold increase in the rate of ovarian cysts in women in clinical trials compared to a placebo. Studies in rats also showed that the drug unequivocally causes ovarian cysts.

A copy of the petition is available at

http://www.citizen.org/hrg/publications/1561.htm

Further, it is unclear if the drug is effective, the petition notes. None of the three pivotal trials demonstrated efficacy according to the original protocol. Even after Novartis altered the parameters of the trial, lowering the threshold for efficacy, just one of the two remaining trials showed some efficacy, and that was modest.

And while tegaserod is to be marketed for constipation-predominant IBS, many of the patients in the trials were not constipated, the petition says.

Added Dr. Elizabeth Barbehenn, research analyst with Public Citizen,

"If the FDA approves this drug, it may well have to be withdrawn because of the high probability of seeing more cases of ovarian cysts once the drug reaches the less-carefully monitored and less healthy population at large."

The petition reminds the FDA of Lotronex, a drug that also was designed to treat IBS (diarrhea- predominant type) but had to be pulled from the market shortly after being approved because of serious adverse effects also known prior to approval.