April, 28 2004 -- The FDA today issued a warning associated with the irritable bowel syndrome (IBS) drug Zelnorm.
The FDA says Zelnorm has been associated with serious cases of diarrhea as well as instances of ischemic colitis -- a medical condition where blood flow is reduced to the intestines.
Zelnorm is a prescription medication for the short-term treatment of women with IBS whose primary bowel symptom is constipation. The FDA says it's adding this new drug information to ensure doctors and patients have the most current and complete information available when prescribing and taking Zelnorm.
The specific revisions include:
A new warning about the serious consequences of diarrhea associated with the medication
A new precaution about ischemic colitis and other forms of reduced blood flow to the intestines
Changes to side effects information section describing information gathered since the drug was approved in July 2002
The New Warning
In the new warning, the FDA states that serious consequences of diarrhea, including significant loss of fluid, low blood pressure, and episodes of passing out, have been reported in the clinical studies and during marketed use of Zelnorm. In some cases, these complications have required hospitalization for rehydration.
The FDA recommends that Zelnorm be discontinued immediately in patients who develop low blood pressure or passing out spells. Zelnorm should not be used in patients who are currently experiencing or frequently experience diarrhea.
The New Precaution
The FDA has also issued a precaution regarding the risk of reduced blood flow to the intestines, which may lead to inflammation of the intestines, called ischemic colitis.
In the new precaution, the FDA states that ischemic colitis and other, similar conditions have been reported in patients taking Zelnorm. Although this association has been observed, the FDA says that Zelnorm has not been proven to cause this effect. The FDA adds that clinical trials comparing Zelnorm to placebo in 7,000 patients for three months showed no cases of these events. This suggests the rate of such events is low, according to the FDA.