Orlistat's Side Effects

OB/GYN News, Dec 1, 1999 by Mike Bykowski

The gastrointestinal side effects at the weight-loss drug orlistat disappear after the first year of use, according to Dr. Samuel Klein, professor of gastroenterology at Washington University, St. Louis.

Results of three large, randomized trials in Europe and the United States show that the unpleasant effects of the drug--including flatulence, oily stools, and fecal incontinence--occur only during the first few months of treatment in most people. These "socially debilitating" side effects "don't constitute a major health threat," Dr. Klein said at the annual meeting of the American College of Surgeons in San Francisco.

It is not known why the side effects disappear, he added. When taken with meals, orlistat, which binds to lipase in the intestines, inhibits absorption of about 30% of the total intake of fat.

The daily recommended dose of 120 mg appears to block the maximum amount of fat absorption.

In clinical trials, 40% of patients lost 10% or more of their body weight within a year, twice the weight loss seen with placebo.

"As marketing focuses more and more on drug therapy for obesity, you'll be approached by increasing numbers of patients [asking for these drugs]," Dr. Klein predicted.

But he stressed that patients treated with any weight-loss drug also should be enrolled in a weight-management program. Otherwise, "you'll expose patients to all the risks of drug therapy without the full benefits."