Advisers to FDA approve diet pill

A panel of medical experts voted overwhelmingly Wednesday to endorse the controversial weight-loss drug Qnexa, clearing the way for the Food and Drug Administration to approve a new prescription obesity medication for the first time since 1999.

The FDA will issue a final ruling later this year, but the agency typically follows the recommendations of its advisory committees.

The 20-2 vote in favor of Qnexa was a surprising reversal from 2010, when the same advisory committee decided that the drug’s risks of heart problems and birth defects outweighed its weight-loss benefits.

In a clinical trial involving 4,323 people, Qnexa – a combination of the anti-convulsant drug topiramate and the appetite suppressant phentermine – led to an average loss of about 10 percent of total body weight in the first year of use. Many users also saw improvements in blood pressure.

But the trials also found that that the drug caused a slight increase in heart rate, which can boost the odds of a heart attack or stroke. In addition, researchers detected an increased risk of birth defects – typically cleft lip – in women who became pregnant while taking the drug.

Vivus Inc., the drug’s manufacturer, addressed those concerns by proposing a tightly controlled system for prescribing Qnexa. To prevent birth defects, patients who take the drug will have to undergo monthly pregnancy testing and health care providers will get special training on the medication’s risks and benefits. Vivus will also restrict distribution of the drug to registered pharmacies, among other measures.