Zelnorm Deemed Safe for IBS Constipation
Watchdog Group Still Worried, but GI Docs Happy
Private practice gastroenterologist and Johns Hopkins clinical
instructor James Novick, MD, headed a major clinical trial of Zelnorm. He says
ovarian cysts simply aren't a real problem for people taking Zelnorm.
"As far as I understand, the ovarian cyst concern holds no
water whatsoever," Novick tells WebMD. "The most common side effect was
headache -- 3% more in [Zelnorm] patients than in placebo patients. Then 5% of
patients get what they consider to be diarrhea, mostly in the first couple of
weeks of treatment. Best of all, there is no interaction with other drugs, not
even SSRI antidepressants. That doesn't seem to happen, which is a real
Novick notes that the only other concern with Zelnorm was that
several patients taking the drug needed gallbladder surgery.
Initially there was a scare the drug might be causing
gallstones symptoms -- that was the data that led the FDA to slow approval, he
says. "That was far more troubling than the ovarian cyst worry. But now it
appears the drug has no effect on the gallbladder. The FDA had a look at the
data before approving the drug, and they were happy enough."
Doctors who treat IBS patients are optimistic but cautious
about using Zelnorm, says gastroenterologist Eri Ehrenpreis, MD, director of
the gastroenterology fellowship training program at the University of
"For the GI doc on the street, the impression has been
positive," Ehrenpreis tells WebMD. "Everybody is a bit gun-shy about
using serotonin-manipulating drugs. Remember, with Lotronex we learned of the
danger only six months after approval. But I think this is a safe drug. If you
look at these studies on IBS patients, these are really very intensively
conducted trials. There are hundreds and hundreds and hundreds of patients who
Ehrenpreis says he thinks Public Citizen doesn't understand
that IBS patients with constipation can't get relief from normal laxatives.
"These organizations that want to put brakes on finding new
treatments -- I'm not sure they appreciate the cost," he says. "We
could keep on having no treatments if we keep raising and raising the bar for
saying when the safety data looks good enough."
Novick says he thinks IBS constipation is only the tip of the
iceberg for Zelnorm. He says he thinks the drug will be an extremely useful
drug for other kinds of constipation -- and for other digestive system