Comstock/Thinkstock(WASHINGTON) — In the search for treatments to fight obesity, regulators have turned their attention to a diet drug that has already failed to receive government approval as a weight-loss treatment.
Next week, a panel of advisers to the U.S. Food and Drug Administration will consider whether to recommend the diet drug Qnexa for approval as a weight loss drug. The move is the latest effort in the battle against obesity, which currently plagues one-third of Americans.
Qnexa was rejected by the FDA in 2010 over concerns about its potentially dangerous side effects, such as cardiovascular problems and birth defects. Now the FDA will again weigh in on whether the drug’s manufacturer, Vivus, should do a larger trial to investigate the potential for cardiovascular side effects.
But some obesity specialists are in effect already getting the drug to their patients by prescribing Qnexa’s two major ingredients, phentermine and topiramate. The practice, called off-label prescribing, is not prohibited by the FDA. Doctors who have prescribed this combination say it has helped patients shed pounds when many other paths to weight loss had failed.
Dr. Jana Klauer, a New York City doctor specializing in weight management, said her patients lose an average of 40 pounds when taking the drugs, along with improved diet and exercise.
“The drug combination gives great results, providing diet and exercise are part of the plan,” Klauer said.
Both phentermine and topiramate are FDA-approved for other uses, but come with their fair share of side effects. Topiramate can create feelings of mental fogginess, memory lapses and a lack of concentration. Phentermine, one of the drugs that made up the failed Fen-Phen, can lead to a range of cardiovascular side effects, such as high blood pressure, heart attacks and heart palpitations.
Dr. Charles Clark, a professor of pharmacology and toxicology at Indiana University, said the laundry list of potential side effects is enough to keep him from prescribing the drug to his patients, particularly in light of Fen-Phen, which was withdrawn from the market in 1997 after causing fatal blood pressure and heart valve problems in patients.
Others say worries about side effects of both drugs and their offspring Qnexa are legitimate but could be managed or avoided if doctors carefully monitor their patients while they’re taking the drug. For example, the FDA’s concerns about potential birth defects associated wtih Qnexa could be resolved by not prescribing the drug to women who could get pregnant. Many doctors say the risks of these drugs may be outweighed by the benefits for some patients with failing health brought on by obesity.
Experts often promote the simple combination of diet and exercise as the safest, most effective way to lose weight. But many also recognize that these methods are largely unsuccessful for certain patients.
“The options we have now are few and mostly ineffective,” Clark said. “As much as I hate to admit it, the only effective option for the chronically morbidly obese patient with other risk factors is bariatric surgery that is not likely to be a universally accepted solution.”
Even physicians who don’t prescribe the drugs say they hope the FDA would approve Qnexa, giving another option to desperate patients and frustrated doctors who have few tools to fight the condition.
“Considering the dismal results that many experience with attempted weight loss with diet and exercise, which is always the first choice, and the explosion in the need and use of bariatric surgery, this combination drug should be a major advance, and I hope that it gets approved this time by the FDA,” said Dr. Chip Lavie, medical director of cardiac rehab and prevention at the Ochsner Clinic Foundation in New Orleans.
Copyright 2012 ABC News Radio