Obesity Drugs Moderate Weight Loss

Obesity Drugs Linked to 'Modest' Weight Loss

Physician's First Watch for November 16, 2007

The principal antiobesity drugs have a "modest" effect on weight loss, and their effect on cardiovascular health "remains unknown," according to a BMJ meta-analysis.

Researchers examined 30 double-blind placebo-controlled studies involving orlistat, sibutramine, or rimonabant (a cannabinoid type-1 receptor antagonist not available in the U.S.). The studies all had high attrition rates, averaging over 30%.

The drugs' effects:

• Orlistat reduced weight more than placebo by 2.9 kg, but produced gastrointestinal side effects, such as oily spotting and fecal urgency;
• Sibutramine provided a 4.2-kg reduction, but raised blood pressure and pulse rate; and
• Rimonabant produced a 4.7-kg weight loss, but had a "worrying" incidence of psychiatric disorders.

Commenting on the lack of mortality data offered in the studies, the authors remind us that "drugs that improve surrogate end points, such as weight loss, may not ultimately improve more clinically relevant outcomes."

BMJ article (Free)