Last week, a U.S. Food and Drug Administration advisory committee voted overwhelmingly to recommend approval for the weight loss drug, Qnexa.
If officially approved later this spring, it will be the first new prescription weight-loss medication to appear on the market since 1999.
In an article written for the Coshocton Tribune, a doctor discusses his opinion about Qnexa.
Marc Siegel, M.D., a professor of medicine and medical director of Doctor Radio at NYU Langone Medical Center, stated, “With one-third of Americans suffering from obesity and another one-third being overweight, a Food and Drug Administration panel’s recommendation that Qnexa be the first new obesity drug to be approved in 13 years would seem to be a no-brainer.”
“But, not so fast,” he continued. “While Qnexa has achieved impressive results in three clinical trials — subjects lost, on average, about 11 percent of body weight — it’s certainly no wonder drug. And many are still concerned over the potential side effects that kept a similar FDA panel from approving the drug in 2010.”
The drug itself is a novel combination of two older drugs: an appetite suppressant with amphetamine like properties; and an anticonvulsant shown to reduce cravings for binge-eaters. In theory, Qnexa works by both increasing the pleasure of food and also reducing the desire to keep on eating, thus making it a bit easier to stick to our diets.
It combines two drugs associated with weight loss: the appetite-suppressant phentermine and the anti-seizure drug topiramate, which appears to alter hunger hormones, decrease appetite and adjust glucose and insulin concentrations.
Though you might be familiar with phentermine from its presence in the infamous weight-loss drug Fen-Phen, phentermine is not the main problem in Qnexa. Fen-Phen was removed from the market in 1997 amid lawsuits for heart valve problems and high pressures in the lungs. But these side effects were caused by the fen (fenfluramine), not the phen.
Phentermine is an effective weight-loss drug that suppresses appetite. Though it can increase heart rate and blood pressure and cause palpitations, for many patients, it is very well tolerated. The concerns with Qnexa center on its other main ingredient — topiramate. Those concerns caused the FDA to reject Qnexa according to Siegel.
So what has changed that an advisory committee would agree for approval? Vivus addressed one major concern and said that it will restrict the drug for pregnant women and perform studies after approval to assess heart safety.
And, they effectively argued to the panel that the growing obesity epidemic is causing massive medical problems and increasing the need for effective treatments. And, if trends continue, it’s estimated that by 2030, the obesity epidemic will account for nearly 20 percent of healthcare spending — five times what’s spent on cancer!
Siegel stated, “Certainly, we need new drugs to treat obesity in patients who are unable to modify their diet or lifestyle enough to lose significant amounts of weight. Perhaps Qnexa might one day be that drug. I would like to see more studies done on Qnexa, however, because its two components (topiramate and phentermine) haven’t been used in combination before, and we need to assess their combined side effects.”
In conclusion, he added, “For the sake of my obese patients who have run out of options, my vote could one day be ‘yes’ for a drug such as Qnexa. But that day isn’t here yet. Right now, the most rational vote is for more studies.”