Zelnorm - Irritable Bowel Syndrome (IBS)

Tegaserod is a 5-HT4 agonist manufactured by Novartis and used for the management of irritable bowel syndrome and constipation. Its use was the only drug approved by the United States Food and Drug Administration to help relieve the abdominal discomfort, bloating and constipation associated with irritable bowel syndrome. Its use was also approved to treat chronic idiopathic constipation. It is currently marketed by Novartis under the trade names Zelnorm and Zelmac in the United States and abroad, respectively.

Mechanism of action

The drug functions as a motility stimulant, achieving its desired therapeutic effects through activation of the 5-HT4 receptors of the enteric nervous system in the gastrointestinal tract. It also stimulates gastrointestinal motility and the peristaltic reflex, and allegedly reduces abdominal pain. Additionally, tegaserod is a 5-HT2B receptor antagonist.

Withdrawal from market

On March 30, 2007, the U.S. Food and Drug Administration requested that Novartis withdraw Zelnorm from shelves. The FDA alleges a relationship between prescriptions of the drug and increased risks of heart attack or stroke. An analysis of data collected on over 18,000 patients demonstrated adverse cardiovascular events in 13 of 11,614 patients treated with Zelnorm (a rate of 0.11%) as compared with 1 of 7,031 patients treated with placebo (a rate of 0.01%). Novartis states all of the affected patients had preexisting cardiovascular disease or risk factors for such, and further states that no causal relationship between tegaserod use and cardiovascular events has been demonstrated. On the same day as the FDA announcement, Novartis Pharmaceuticals Canada announced that it was suspending marketing and sales of the drug in Canada in response to a request from Health Canada. Some manufacturers in India, such as Cipla, seem to still have generic Tegaserod available in their listings and some onlinemerchants may be selling it.

Data

Systematic (IUPAC) name: 2-((5-Methoxy-1H-indol-3-yl)methylene)-N-pentylhydrazinecarboximidamide