A committee of experts voted 20 to 2 Wednesday that the Food and Drug Administration should approve the weight loss drug Qnexa despite concerns about its safety. We think that even if the FDA ultimately approves the drug, you should probably skip it.

Two years ago, the FDA had rejected the drug—a combination of the stimulant phentermine (Adipex-P, Atti Plex P, and generic) and the anticonvulsant medication topiramate (Topamax and generic)—because of concerns about possible birth defects, heart attacks, and strokes.

The advisory committee said that after the drug is approved, its manufacturer—Vivus—should conduct a study to monitor for possible heart problems, and also come up with a plan to reduce the risk of serious adverse events that might be associated with it.

Marvin Lipman, M.D. chief medical advisor for Consumer Reports, says that such post-market studies often aren't adequate:

Post-approval surveillance is not a very safe quid pro quo since this drug will be used by millions—perhaps with dire consequences. The components of Qnexa are known entities with impressive side effects.

The individual components of Qnexa have been linked to several serious potential risks. Phentermine carries a warning about the possibility of heart-valve problems. Topiramate carries warnings about glaucoma, depression and mood problems, and the FDA cautioned last year that it should not be taken by pregnant women or those trying to become pregnant because it increases the risk of their children being born with a cleft lip or palate.

Bottom Line: We recommend generally avoiding all weight-loss drugs and supplements. Their benefits are usually marginal and even if they do help you lose weight, the side effects can be troublesome and even dangerous.

If you need to lose weight, increasing exercise and limiting portion size when it comes to food are better options. Read more about weight loss pills and safe, effective ways to control your weight.

Sources
Diet drug gets thumbs-up from FDA panel [NPR]
FDA Advisory Committee Recommends Approval of Qnexa [Vivus]