What is Qsymia?
The combination of the drugs phentermine and topiramate extended-release (ER) (trade name Qsymia) is a medication used for weight loss. In clinical trials, phentermine/topiramate ER was associated with modest but statistically significant weight loss when compared with placebo.
Phentermine/topiramate ER was developed by Vivus, Inc., a California pharmaceutical company. Topiramate is an anticonvulsant that has weight loss side effects. The exact mechanism of action for both drugs is unknown.
In 2012 the U.S. Food and Drug Administration approved phentermine/topiramate ER as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index (BMI) of at least 30 kg/m², or at least 27 kg/m² (overweight) in the presence of at least one weight-related comorbidity such as hypertension, type 2 diabetes mellitus, or dyslipidemia. Phentermine/topiramate ER is available in certified retail pharmacies nationwide and also available through a certified mail-order pharmacy network. Approval was denied by European regulatory authorities, who cited potential risk to the heart and blood vessels, psychiatric side effects, and cognitive side effects in explaining their decision.