March 30, 2007Novartis withdraws Zelnorm at FDA’s request
At the request of the Food and Drug Administration, Novartis Pharmaceuticals has withdrawn its irritable bowel syndrome (IBS) drug Zelnorm in the United States. The decision to stop sales or marketing of the drug was made after studies linked Zelnorm to an increased risk of heart attacks, strokes and other cardiovascular side effects.During a routine safety review of Zelnorm, Novartis examined 29 studies which indicated that patients taking the drug were almost eight times as likely to experience cardiovascular side effects as patients who were given a placebo. Because of the risk of Zelnorm side effects, the FDA is advising doctors who prescribed the drug to their patients to switch them to another medicine.
Although officials at the FDA say that the cardiovascular side effects of Zelnorm are rare, data from Novartis’ studies indicated that the drug’s risks outweighed its benefits. Zelnorm is only about 6% more effective at treating constipation caused by IBS than a placebo.
According to the FDA, Novartis is planning to issue a Zelnorm recall, although the agency may allow patients who do not respond to other drug therapies to continue taking Zelnorm. In addition to the risk of cardiovascular side effects, previous studies have linked Zelnorm to an increased risk of ovarian cysts and ischemic colitis (inflamed colon).