A group of medical experts has endorsed a new diet drug to combat obesity, recommending it to the U.S. Food and Drug Administration for approval later this year. But some say that the health risks associated with the drug, Qnexa, are greater than any weight-loss benefit it may provide.
In a clinical trial involving 4,323 people, participants lost an average of 10 percent of their total body weight in the first year of using Qnexa, and some saw improvements in blood pressure as well.
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But less than two years ago, the same panel of experts decided that Qnexa was too dangerous to put on the market, since it had a documented history of causing heart problems and birth defects.
What made them change their minds?
Turns out it was a simple promise and a plan: The drug's manufacturer, Vivus Inc., agreed to keep a close eye on patients who are prescribed Qnexa, making them take monthly pregnancy tests (to avoid the possibility of birth defects) and restricting distribution of the drug to a handful of registered pharmacies. Healthcare providers will also have to go through special training on the risks and benefits of the drug.
“We will know who the prescribers are. We will know who has been trained," Dr. Barbara Troupin, the senior director of global medical affairs at Vivus, told the FDA advisory committee. "We are confident the Qnexa risk management program balances the safeguards while allowing access for appropriate patients."
Qnexa is a combination of topiramate, an anti-convulsant, and phentermine, an appetite suppressant. If phentermine sounds familiar, it's because it's not new to the weight-loss world: It was a key ingredient in fen-phen, a combination drug (with fenfluramine) which was taken off the market by the FDA in 1997 for causing heart-valve problems in women.
As of right now, only one prescription weight-loss drug is available in the United States. Xenical works by blocking the absorption of fat; Qnexa works by suppressing the appetite and increasing feelings of fullness. It would be the first new diet drug approved by the FDA since 1999.
If approved, the drug would be marketed to people who are considered medically obese, with a Body Mass Index (BMI) of 30 or above; those with weight-related health problems like diabetes would be eligible for the medication if their BMI is 27 or above. (You can calculate your BMI here.)
"The most encouraging thing is that just about every member really heard the message about the need to treat obesity," Ted Kyle, the advocacy committee chairman of the Obesity Society, told The Los Angeles Times. "Obesity is not a trivial disease."
According to the U.S. Centers for Disease Control and Prevention, more than a third of Americans are obese, and another third are overweight. "Increased risk for developing problems such as high blood pressure, diabetes, liver disease-all the things that can happen as a result of having a high BMI," Dr. Susan J. Woolford, the medical director of the Pediatric Comprehensive Weight Management Center at the University of Michigan, told Yahoo! Shine. According to the American Cancer Society, obesity will soon top smoking as the leading cause of cancer in the United States.
Experts were skeptical about Qnexa's effectiveness. "Diet drugs simply don't work," Dr. Joe Colella, a bariatric surgeon and the author of "Skinny People Just Don't Get It," told Yahoo! Shine. "The magic pill is never coming. Our collective addiction to high-sugar diets is the real problem."
"When people use these drugs, they are minimally effective at best, and upon cessation, any weight lost is immediately regained, plus a little extra," he warned. "In addition, most of us will take license to continue our unhealthy eating habits while we are losing the insignificant pounds that will soon be regained."
The FDA panel voted 20-2 to endorse Qnexa; the FDA typically follows the recommendations of its advisers. Dr. Michael S. Lauer, director of the division of cardiovascular sciences at the National Heart, Lung and Blood Institute, voted against it, saying that the FDA should first ask Vivus to provide more detailed cardiovascular risk data.
"We have seen many cases in medicine where we thought we understood the pathology of disease … and we turned out to be wrong," he told the LA Times. "With an epidemic as serious as obesity, we need to do this right."
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