FDA Panel Rejects Diet Drug Over Safety Worries : Shots - Health News Worries about birth defects and other side effects led to a 10 to 6 vote against a new diet drug by an FDA panel.

Diet Drug Qnexa Gets Thumbs-Down In Avandia's Wake

The menu may not have a new diet medicine anytime soon. iStockphoto.com hide caption

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We're not going to say we saw this coming exactly.

But, in hindsight, it's not altogether surprising that an expert panel came out against a diet drug called Qnexa Thursday, the day after a lot of the same folks voted to keep the diabetes pill Avandia on the market despite heart risks.

The vote -- 10 to 6 against Food and Drug Administration approval -- dealt a blow to Vivus, maker of the medicine, and many overweight people looking for a new tool to help them shed pounds. It's also a ominous sign for two other weight-loss pills that are expected to be vetted later this year.

What was the problem with Qnexa? Risks ranging from birth defects for babies conceived when women were taking the drug to an increased heart rate common among people taking Qnexa.

Even though people taking the highest doses of Qnexa had lost more than 10 percent of their weight a year after starting the medicine, the risks were too high, the federal panel concluded.

After essentially supporting continued sales of problem-plagued Avandia, though with restrictions, the panel members may have felt it was time to get tough on a drug with baggage. Past problems when millions of people took diet drugs that harmed them -- notably the drug cocktail known as fen-phen -- also hung over the deliberations.

Qnexa is a combination of two old drugs: the epilepsy medicine topiramate and phentermine, the half of the fen-phen cocktail that didn't cause heart problems.

The FDA is expected to make a decision on Qnexa by the end of October. The agency usually follows the advice of advisory panels, but not always.

For its part, Vivus said it will work with the FDA to address the questions raised during the hearing. In the next few months, the company expects to have additional safety data from longer-term study of the medicine. It's unclear if that information will be enough to support approval of Qnexa.