Women who suffer constipation-causing irritable bowel syndrome won their first government-approved treatment Wednesday. 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 on Wednesday 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 with 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 said.
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.
On Wednesday, 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.
A consumer advocacy group attacked the FDA's decision, saying officials were ignoring early signals of risks.
Novartis said sales should begin in early fall. It declined to release the price but suggested the tablets will be in the range of $3 to $4 each.