IBS Drug Withdrawn After Less Than a Year on the Market
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.
The FDA has maintained that while Lotronex's relationship to ischemic colitis may not be understood, there is ample evidence to show that the drug is at least being improperly used to treat patients who do not stand to benefit from the medication. In effect, according to the FDA, that means a number of patients are being exposed to unnecessary risk of both ischemic colitis and constipation. Clinical trials have shown that while Lotronex may greatly benefit women with diarrhea-predominant IBS, but the drug also has been shown to have little to no benefit for men, as well as for women whose predominant symptom is constipation, the agency explains.
There also are strong signals for a possible risk, some consumer groups say. According to Public Citizen, a prominent consumer watchdog group, the drug has been linked to at least 54 cases of ischemic colitis as of October, making it "irresponsible for Glaxo Wellcome and for the FDA to allow this doomed drug to stay on the market any longer." Public Citizen, among other consumer groups, has called for the drug's withdrawal since August.
But while Lotronex's association with ischemic colitis might now never be fully understood, the withdrawal is sure to once again raise the issue of whether U.S. health authorities are moving too quickly in approving new drugs. In the span of just two years, the agency has called for the withdrawal of about six drugs, raising questions about the merits of the system that brought these drugs to the public in the first place.
Critics say the withdrawals prove that the agency has lowered its safety standards in approving drugs. But agency supporters say these actions are inevitable because some adverse events, such as ischemic colitis, are rarely caught during the clinical trials conducted to support a drug's approval.