IBS Drug Zelnorm Taken Off U.S. Market

March 30, 2007 -- A popular drug for irritable bowel syndrome and constipation was pulled from the U.S. market Friday amid new evidence that it raises the risk of heart attacks and strokes.

Novartis, the manufacturer of Zelnorm, confirmed that Food and Drug Administration officials asked for the drug’s withdrawal.

Agency officials said they based their decision on a Swiss government analysis of 29 Zelnorm studies that showed a higher chance of cardiovascular events, such as heart attack, stroke, or severe heart-related chest pain in patients treated with Zelnorm compared with those given a placebo.

The analysis turned up 13 cases of heart attack, stroke, or angina (chest pain related to heart disease) in about 11,600 patients who took the drug. One of the 13 died, the agency said. This was compared with just one nonfatal event in more than 7,000 patients who took the placebo.

John Jenkins, MD, head of the FDA’s Office of New Drugs, described the overall number of dangerous events as “quite small.” But he said the rate of cardiovascular events -- about 10 times higher in patients taking Zelnorm -- raised alerts about the drug.

“Based on our review of the data we believed that the risk vs. benefit profile for Zelnorm was no longer favorable,” Jenkins told reporters on a conference call.

He said patients taking Zelnorm should speak immediately to their doctors.

Special Access to Zelnorm

Though the drug will no longer be widely available, patients who have no other treatment options could still get access to the drug. The FDA said it is likely to allow Novartis to continue selling Zelnorm to patients if their doctors say they have disease that does not respond to any other treatment and if the benefits of treatment with Zelnorm outweigh the risks of serious side effects. Drug access would be done through a special program.

The FDA says it has told Novartis that it's willing to consider limited reintroduction of Zelnorm at a later date if a population of patients can be identified in whom the benefits of the drug outweigh the risks. 

However, before the FDA makes a decision about limited reintroduction, any proposed plan would be discussed at a public advisory committee meeting. 

In a statement, Novartis maintained that no evidence proves that Zelnorm caused heart attack or strokes and that event rates were not significantly different from those in the general population. But the company confirmed it would pull Zelnorm from the market.

“Novartis has suspended the marketing, sales, and distribution of Zelnorm in response to the FDA's request,” the statement read.

Novartis is a WebMD sponsor.

Zelnorm was approved for short-term treatment of women with irritable bowel syndrome (IBS) with constipation and for patients younger than 65 years with chronic constipation.

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