New Diet Drug Promises 10% Weight Loss-but what is the cost?
On Wednesday 02/22/2012 an FDA advisory panel voted 20-2 to recommend approval of Qnexa, the latest offering from pharmaceutical company Vivus. Qnexa is a “cocktail” (combination) drug that was rejected by the FDA in 2010 due to the high occurrence of dangerous side effects.
The FDA is likely to approve this drug on the recommendations of the panel despite the 2010 rejection. Why? The FDA isn’t locked into a set of standards that apply to all drugs of all types. It raises and lowers the bar based on what is available in the market that does the same job. The FDA is constantly considering the risks and benefits of new drugs. If the benefit is more, even slightly, than the problem it is designed to combat, and then the risk is justified by the potential benefit. Phentermine has been available for more than 40 years and Topiramate has been around for some time as well. What does mean as far as FDA approval of the Qnexa? Since both drugs are approved separately, there isn’t as much testing needed for the combination.
What is Qnexa?
Qnexa is a combination of two other previously approved FDA drugs, Phentermine-an appetite suppressant and Topiramate- an anti-convulsant used in the control of seizures. If the name phentermine sounds familiar that’s because it was the “phen” in Fen-Phen which was withdrawn from the market due to the damage it caused to heart valves.
On the plus side, the data collected from the studies (yet to be published) done by Vivus show a 10% loss of weight over a year and outperforms placebo but then so does every diet drug out there. The study states: “patients taking Qnexa have demonstrated statistically significant weight loss, glycemic control, and improvement in cardiovascular risk factors, when used in combination with a diet and lifestyle modification program” (sounds like diet and exercise doesn’t it). It should also be noted that 16-19% of the test participants dropped out of the testing due to the severity of the side effects.
What are the potential side effects?
Along with dry mouth, sleeplessness and constipation, there is the potential for heart valve damage, increased blood pressure, and possible birth defects when taken by women that are pregnant.
Let’s break it down into each component drug.
Phentermine is known to have two heart-related side effects: increased heart rate and elevated blood pressure.
The NIH’s backgrounder on phentermine states that those with even moderately elevated blood pressure, hypothyroidism and “excitability “should not use the drug. In addition, phentermine’s “anorectic” effects last for a few weeks and require higher doses to get the same effect the longer the patient uses it.
Topiramate has a rather high instance of confusion, memory loss, problems concentrating and “psychomotor slowing” causing along with other things difficulty finding the correct words.
The NIH topiramate carries warnings for depression, mood problems, fatigue, and sleeplessness. Then add to that the suicidal ideation. These side effects aren’t considered as serious as the potential heart damage they are significant and the incidence is surprisingly high. In all 42% of those that take topiramate reported one or more mental or cognitive problems. Pharmacology reports found that babies born to mothers taking topiramate had a high incidence of cleft palate.
The FDA panel is concerned enough with the potential long term side effects that it is recommending that Vivus conduct a four year study after the FDA votes whether or not to approve the drug on April 17th. This sounds like the proverbial cart before the horse scenario. So if you decide to take Qnexa you will be one of the guinea pigs watching for side effects.
In our countries desperation to find a solution to the obesity epidemic, we are willing to try anything that is quick and “easy” no matter what the risks, while ignoring the root causes to the problem. We as a country need to address the underlying causes of this epidemic and take action, not a pill.