IBS Drug Withdrawn After Less Than a Year on the Market
Nov. 28, 2000 (Washington) -- The first of a new class of drugs being developed to treat irritable bowel syndrome (IBS) has been withdrawn from the U.S. market less than a year since its approval.
Glaxo Wellcome, the U.K.-based drug manufacturer, said Tuesday that it would immediately withdraw its highly controversial IBS drug Lotronex at the request of the FDA. The company also said that it would abandon its plans to sell Lotronex in other countries.
Since Lotronex has become available in March, more than 450,000 prescriptions for the drug have been distributed. At the latest count, according to the FDA, there were 49 reported cases of ischemic colitis, a potentially life-threatening inflammation of the large intestine, and five deaths.
In February, the FDA approved Lotronex for treating women with IBS who suffer from diarrhea as the predominant symptom of their condition. It was the first medicine approved in years for the treatment of IBS, a recurring condition characterized by abdominal pain and irregular bowel function. The condition affects about 15% of all Americans, most of whom are women.
Glaxo Wellcome said it decided to withdraw the drug after in-depth discussions with the FDA, in which agency officials expressed their concern about the company's ability to limit the drug's side effects. The drug has been associated with the rare condition ischemic colitis, and it has been linked to a severe form of constipation, which at times may require surgery. The FDA began re-evaluating the drug's risks and benefits in October.
But in withdrawing the drug, Glaxo Wellcome noted that it disagreed with the FDA's final assessment that withdrawing the drug represented the best solution. "We greatly regret this outcome and believe that Lotronex is effective, that its side effects are manageable, and the benefits of the product when treating IBS outweigh the risks," said James Palmer, MD, the company's senior vice president for regulatory strategy, in a prepared statement.
The connection between Lotronex and ischemic colitis has not been firmly established, and therefore, the risk still appears minimal, explains Richard Kent, MD, the company's chief medical officer in the U.S. The reports also might just reflect the true incidence, or the actual number of cases, of ischemic colitis in the U.S., he tells WebMD. Currently, the estimated incidence is about three cases for every 10,000 people. But the relatively mild form of ischemic colitis associated with Lotronex "probably occurs more frequently than is recognized," he says.
As for the constipation that sometimes develops while patients take the drug, "We feel that it is totally manageable," Kent says. Physicians are perfectly familiar with that condition, and there were only a few cases in which patients required surgery, he tells WebMD.