FDA Rejects New Drug for Irritable Bowel Syndrome
Dominique Walton, MD
Editor's Note: In March 2007 the FDA asked Novartis -- the maker of
Zelnorm -- to pull the drug from the market because of evidence that it raises
the risk of heart attacks and stroke. But in July 2007 the FDA ruled that
Zelnorm may be used by some patients in critical need of the drug who do not
have heart problems.
June 20, 2001 (Washington) -- The FDA decided not to approve
the drug for irritable bowel syndrome, or IBS, called Zelnorm, despite an
approval recommendation from the regulators' own advisory committee.
In a letter to Novartis, the manufacturer of Zelnorm, the FDA
said it rejected the drug because of concerns that it may necessitate surgery
to remove the gall bladder in some people, company spokeswoman Jill Pozarek
tells WebMD. The FDA said that more data on the association between the drug
and gall bladder removal would be required before it could be approved.
"There is no evidence that the drug would result in [gall
bladder] surgery," Pozarek says. She notes that only six people out of the
more than 4,500 enrolled in clinical trials of Zelnorm had to have their gall
bladder removed. And one of the six was in the placebo group and did not take
IBS patients often have to undergo this type of surgery, she
says, so it's difficult to attribute all the surgery cases to the drug.
However, Steven Itzkowitz, MD, chief of gastroenterology at the
Mount Sinai School of Medicine, tells WebMD that although IBS patients may
often have symptoms that resemble gall bladder problems, he's not aware of them
undergoing gall bladder removal surgery more often than the general
Symptoms of IBS include abdominal pain, constipation, and/or
diarrhea. The IBS Self Help Group, a patient advocacy organization, estimates
that as many as 4.7 million Americans suffer from the condition and about 70%
are women. IBS has no known cause, and there is no drug specifically indicated
for the condition.
IBS can be so disruptive to a person's daily life that many
sufferers have said they would be willing to accept the risk of gall bladder
removal for a chance at relief, says Jeffrey Roberts, president and founder of
the IBS Self Help Group and an IBS patient himself.
Last November, the FDA forced the IBS drug Lotronex to be taken
off the market. Lotronex, which was made by Glaxo Wellcome, appeared to be a
promising treatment for IBS when it was approved in February, 2000, but the FDA
decided to remove it from the market after receiving complaints of serious
gastrointestinal problems, including five deaths, possibly associated with the
Novartis feels that the FDA may be taking a cautious approach
to Zelnorm because of Lotronex, Pozarek says. Public Citizen's Health Research
Group, a consumer advocacy organization, could be another factor. In March, the
watchdog group filed a petition with the FDA claiming that Zelnorm increases a
woman's risk for developing ovarian cysts. The drugmaker disagrees and says
Public Citizen's concerns were based on incomplete information.