FDA approves new irritable bowel treatment
By Steve Mitchell
UPI Medical Correspondent
Science & Technology
Published 7/24/2002 3:30 PM
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WASHINGTON, July 24 (UPI) -- The Food and Drug Administration Wednesday approved the first and only drug for treating constipation in women due to irritable bowel syndrome, a condition that causes abdominal pain, discomfort and bloating in millions of women.
The medication, called Zelnorm and is manufactured by the Swiss company Novartis, helps speed the movement of waste through the bowels. It will help "a substantial number of people" because currently available treatments are not very effective for this disease, Walter Peterson, a gastroenterologist at the University of Texas-Southwestern School of Medicine in Houston, told United Press International.
"These people are often miserable but the things we have today do not treat all their symptoms," Peterson added. Typical treatments for irritable bowel syndrome or IBS consist of bulking agents such as Metamucil, low-doses of anti-depressant medications and drugs that relax the muscles in the bowels, but the effectiveness of any of these agents is debatable, he said.
Peterson said he thinks Zelnorm has the potential to treat the pain, discomfort, bloating and constipation associated with IBS. In addition, this disease often causes people to miss work and Zelnorm could help reduce the number of days of absenteeism, he said.
Novartis said in a statement IBS is "second only to the common cold as a leading cause of workplace absenteeism in the U.S." and the condition "costs the U.S. healthcare system up to an estimated $30 billion annually in direct and indirect costs."
Zelnorm "is a much needed drug," Jeffrey Roberts, president and founder of the IBS Self Help Group, told UPI. He noted women involved in the clinical trials have already told him the medication has helped. "Women are suffering without this drug," he said, adding that anywhere between 15 million to 30 million women have the constipation form of IBS.
Zelnorm will have to overcome the stigma of Lotronex, the only other drug ever approved for the treatment of IBS. Lotronex was pulled off the market by its manufacturer, the British company GlaxoSmithKline, in 2000 after it was associated with five deaths and several cases of bowel damage so severe they required surgery. Just last month the FDA allowed the drug back on the market but only under very restricted conditions.
Where Zelnorm is indicated for constipation, Lotronex was approved for the treatment of diarrhea due to irritable bowel syndrome and it works by a completely different mechanism.
"These are absolutely totally different drugs," Peterson said. They act on different receptors and have different effects in the body, he said. In addition, no indication of ischemic colitis -- a dangerous bowel condition that was associated with Lotronex -- has been seen in studies of Zelnorm, he said.
Roberts, who has followed both Zelnorm and Lotronex closely, agreed, saying, "The side effects are very different" and there does not seem to be any concern about the safety of Zelnorm.
However, Zelnorm was only approved for short-term use and the FDA noted in a written statement it delayed approving the drug until Novartis resolved concerns about "conflicting results in the efficacy studies and outstanding safety questions."
The FDA based its decision to approve Zelnorm on three clinical trials of the drug involving more than 2,400 women with IBS. Patients receiving the drug reported an improvement in pain, bloating and constipation but this improvement declined after three months, which suggests "efficacy may decrease over time," the FDA said.
The main side effects consisted of diarrhea, most cases of which disappeared after the first week of taking the drug. There also was an increase in abdominal surgeries in patients taking Zelnorm compared to those receiving an inactive placebo and most of these were due to gall bladder removal surgery. However, the FDA noted the surgeries did not seem to be required due to Zelnorm.
Roberts predicted although Zelnorm has been approved for women, physicians will prescribe it for men suffering from IBS as well. But Peterson said he hopes that will not happen, primarily because not enough men were included in studies of the drug so it could produce side effects in them that were not seen in women.
In addition, in light of the problems with Lotronex, physicians are apt to be cautious with Zelnorm and probably will use it only exactly as it is indicated, Peterson said.
As the FDA noted in its statement, "The safety and effectiveness of Zelnorm in men have not been established."
Novartis spokeswoman Laura Hortas told UPI the company has no immediate plans to study the drug in men. She said Zelnorm should be available in the United States in the next three weeks to four weeks.
Copyright © 2002 United Press International
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