Qsymia: Another New Obesity Drug Approved Today

Posted: Jul 17 in Weight Loss Medication by Dr. Lazarus

After a 13 year hiatus, 2012 is an exciting year for obesity treatment. Hot on the heals of approving Belviq for obesity treatment, today the FDA approved another drug, Qsymia (formerly called Qnexa). This is exciting for a lot of reasons, but what impresses me most is that we now have two new obesity treatments approved for long-term use (> 1 year), whereas up until now, our primary obesity drugs, Phentermine and Tenuate, were only approved for short-term use (up to 90 days).
Qsymia is a combination of 2 drugs: Phentermine and Topiramate. Phentermine has been used as a weight loss drug for over 50 years. Topiramate is more commonly known as a medication both to prevent seizures and to prevent migraine headaches. Weight loss has long been known to be a side effect of Topiramate. Vivus pharmaceuticals has been studying this combination for several years. By combining time-released versions of both drugs at doses intended to maximize results and minimize side effects, the drugs act synergistically to reduce weight. What does this mean in English? Simply, 2 plus 2 equals 10.

Originally Qsymia faced an uphill battle when the FDA did not approve it back in 2010 due to concerns about side effects and concerns about its safety profile. Phentermine has known stimulant properties, and can raise blood pressure and heart rate. Clearly, this component of the drug is not safe in patients with heart disease or something similar, or at high risk for vascular problems. Topiramate on the other hand also has some risks. In addition to potential for side effects of memory issues and word recall, it is not recommended to be on Topiramate if one is to become pregnant as it increase the risk of cleft lip / palate.

However, Vivus’s hope in combining the two drugs is that by using the combination, they can offer a lower dose of each drug, minimize side effects, and that the side effects might offset each other (the stimulant effects of Phentermine may offset the cognitive effects of Topiramate). In any event, in clinical trials, patients treated with Qsymia not only lost an average of 10% of their body weight, but kept it off (Obesity medicine specialists all agree that this is key – keeping it off is the hardest part).

With Belviq and now Qsymia approved, we finally have 2 new, powerful weapons to treat obesity. Further details regarding release dates and availability will follow – no information on this is available, yet.