WASHINGTON -- Women who suffer constipation-causing irritable bowel syndrome won their first government-approved treatment yesterday.
But while its maker predicts Zelnorm will prove a blockbuster, a critic contends health authorities should not have let it be sold.
Zelnorm's approval comes just weeks after the Food and Drug Administration let another controversial bowel drug, Lotronex, back on the market, two years after serious side effects halted its sales.
The two drugs are for different types of irritable bowel syndrome, a mysterious disorder that gives millions of Americans, mostly women, abdominal pain and either severe diarrhea or constipation or both. Lotronex is for the diarrhea type, while Zelnorm yesterday became the only FDA-approved therapy for women with constipation-predominant IBS.
Until now, these women could try laxatives, but they did not relieve the cause of IBS. Zelnorm appears to go a step further, acting on nerve cells to speed the colon's movement of stools.
It is far from a cure. In studies, patients fared only a little better -- 5 percent to 11 percent better -- when taking Zelnorm than when taking dummy pills.
It has not been studied in men, and seems to work best the first month before its effects wane after three months of treatment, the FDA concluded.
Still, the government was on track to approve Zelnorm a year ago when instead it abruptly halted, citing concern about an increase in gall bladder and other abdominal operations among patients testing the drug. European regulators raised similar concerns.
Yesterday, the FDA reversed course and approved Zelnorm's sale, saying the extra surgeries so far appear to be coincidence.
To be sure, the FDA ordered Zelnorm maker Novartis to study how patients fare as sales begin, and pledged to closely monitor any reports of side effects.
"We're all very interested in looking at this to make sure it doesn't turn out to be something unwanted," said Dr. Joyce Korvick, FDA's deputy director of gastrointestinal drugs.
A consumer advocacy group attacked the FDA's decision, saying officials were ignoring early signals of Zelnorm risks just as the agency two years ago downplayed a few bowel inflammations and other complaints that eventually derailed Lotronex.
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