More Upsetting News About Irritable Bowel Treatment
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
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
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the drug to be withdrawn.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.