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More Upsetting News About Irritable Bowel Treatment

By Ori Twersky
WebMD Health News

Oct. 31, 2000 (Washington) -- Following 49 reports of a serious bowel condition called ischemic colitis and five reported deaths among people taking Lotronex, a drug for irritable bowel syndrome (IBS), U.S. health officials are re-evaluating the risks and benefits of the drug. Though the FDA has yet to review the reports, and though a link with Lotronex has not been established, enough concern has been raised to warrant further investigation.


FDA officials confirmed Monday that they are re-evaluating Lotronex after the prominent consumer watchdog group Public Citizen released a letter urging FDA Commissioner Jane Henney, MD, to withdraw the IBS drug from the U.S. market. In the letter, the group said that the drug was linked to 54 cases of ischemic colitis, making it "irresponsible for Glaxo Wellcome and for the FDA to allow this doomed drug to stay on the market any longer."


IBS is a disorder of the large intestine that is characterized by abdominal pain and either constipation or diarrhea. It affects mostly women and occurs in about 15% of Americans, or five out of every 1,000 people. Ischemic colitis is a potentially life-threatening inflammation of the large intestine that is caused when blood flow to that area of the gastrointestinal tract is blocked.


Lotronex, made by the U.K.'s Glaxo Wellcome, blocks certain receptors for serotonin, a chemical that relays sensations from the body to the brain. The blocked receptors, which are found throughout the gastrointestinal tract, are thought to play a large role in relaying the sensation of pain from the intestines to the brain. The receptors also are believed to help regulate certain bowel functions.


This is not the first time the FDA has investigated a link between Lotronex and ischemic colitis, or that Public Citizen has called for the drug to be withdrawn. In late June, an expert panel of the FDA reviewed the link and concluded that a stricter warning label might be warranted -- even though the rate or cause of ischemic colitis was not fully understood. Then in August, Public Citizen called for the drug's withdrawal, citing the FDA's own publicly declared concerns as the basis of its complaint.


Following the expert panel review, the FDA did require that an easy-to-read pamphlet explaining the risk of ischemic colitis, as well as the risk of severe constipation, be distributed to all patients taking the drug. The unprecedented move was ordered in August, when the FDA was aware of about 33 severe cases of both ischemic colitis and severe constipation. The FDA now has received 21 reports of severe constipation.


While it is fair to say the additional reports have prompted the FDA to re-evaluate the drug's benefits and risks, it is still too early to say that Lotronex is responsible for the reported side effects or deaths or that the new reports really reflect any increased risk to patients, an agency spokesperson concedes. Speaking on condition of anonymity, he tells WebMD that the federal agency expected to receive additional reports of ischemic colitis after ordering the consumer pamphlet be distributed because of all the media hype surrounding the issue.

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