Zelnorm Side Effects
Researchers in 2006 thoroughly analyzed the clinical trials Novartis conducted on its irritable bowel syndrome (IBS) drug Zelnorm. What they found was troubling—a heightened risk of serious cardiovascular events as a result of Zelnorm side effects.
The scientists found 13 cases of Zelnorm heart attacks, strokes or other cardiovascular side effects among patients who took the drug. When adjusted for the size of each group, this means that the risk of Zelnorm side effects from cardiovascular problems is eight times that of a placebo.
Heart problems
The increased rate of cardiovascular Zelnorm side effects in patients has puzzled doctors. Dr. John Jenkins of the FDA’s Office of New Drugs says that Zelnorm appears to work by the creation of wavelike movements in the stomach and intestines. These, he theorizes, soothe the symptoms of constipation and IBS but may also produce a similar reaction in the arteries leading up to the heart. This interaction may be the cause of the high rate of Zelnorm side effects.
When the FDA learned about the drug trials and patients’ risk of Zelnorm heart attacks and other cardiovascular problems, it asked Novartis to issue a Zelnorm withdrawal and stop marketing and selling the drug in the United States. The company reluctantly agreed to do so.
According to the FDA, Novartis is now planning to issue a full Zelnorm recall in order to sweep the drug from pharmacy shelves. No date has been set on that action, however.
Intestinal ischemia and related problems
Zelnorm was initially rejected by the FDA over concerns that it posed too great a risk of causing abdominal problems in patients. Studies conducted by Novartis showed that patients taking Zelnorm needed surgery five times as often as those taking a placebo to correct gall bladder or other abdominal problems.
In 2004, two years after Zelnorm was finally approved, the agency decided to update its labeling to warn of the drug’s stomach and digestive side effects. Many people who used Zelnorm have developed intestinal ischemia—decreased blood flow to the intestines.
The symptoms of intestinal ischemia include abdominal pain, fever, nausea, frequent bowel movements and vomiting. Death is sometimes the unfortunate result.
