The Food and Drug Administration is expected to announce tomorrow if it will approve the obesity drug Qnexa. If approved, it would be the first new diet drug to hit the market in more than a decade.Research shows the drug can help people lose weight, reduce diabetes and lower blood pressure. But there are safety concerns.There’s evidence it can cause a patent’s heart rate to quicken, and may also increase the risk of cleft lip in babies when pregnant women take the drug.
If approved, Qnexa (pronounced kyoo-NEX-uh) will become the second diet drug approved this year. The FDA approved a weight-loss pill called Belviq on June 27. Patients in clinical trials experienced more dramatic weight loss with Qnexa than with Belviq. On Qnexa, patients went from an average 227 pounds to 204 pounds; on Belviq, the average weight dropped from 220 to 207.
But some consumer advocates worry that the weight loss comes with a price. Some patients in the clinical trial suffered an increased heart rate and a condition called metabolic acidosis, which can lead to hyperventilation, fatigue and anorexia. Concerns have also been raised about birth defects. One of the ingredients in Qnexa is topiramate, an anti-convulsant that has been linked to birth defects such as cleft lip and cleft palate in babies born to women who have taken it for migraines or seizures. Qnexa’s other ingredient is phentermine, an appetite suppressant.
“Our belief is that women will be invited to compelling advertising and marketing messages to experiment on themselves with a drug that has some effectiveness with healthy weight loss but possible serious risks,” said Cindy Pearson, executive director of the National Women’s Health Network. Qnexa’s manufacturer, Vivus Inc., says that the drug helped lower blood pressure and cholesterol levels in obese people and that people taking it were less likely to get Type 2 diabetes.
“Obesity is not being adequately addressed by diet and lifestyle changes or currently available therapies,” the company said in a statement. “The need for new options is urgent, particularly non-surgical options.” The FDA is expected to approve Qnexa only for obese people or for overweight people with a body mass index greater than 27 who also suffer from weight-related conditions like hypertension and diabetes.
Doctors are free to prescribe the drug to anyone, however, and there are concerns that physicians will open “pill mills” and prescribe Qnexa to people who just want to lose a few pounds. That’s what happened in the 1990s with fen-phen, another diet drug combination that includes phentermine. An FDA advisory committee voted against Qnexa’s approval in 2010. The panel recommended the drug’s approval with a 20-2 vote in February, after Vivus proposed a risk management program to limit Qnexa’s distribution and published additional results from one of its three clinical trials.