When are phentermine and topiramate (Qsymia) indicated in the treatment of obesity?

Updated: Jun 09, 2021
  • Author: Osama Hamdy, MD, PhD; Chief Editor: Romesh Khardori, MD, PhD, FACP  more...
  • Print

The combination of phentermine and extended-release topiramate (Qsymia) was approved by the FDA in July 2012 as an adjunct to a reduced-calorie diet and exercise for long-term weight management in individuals with an initial BMI of 30 kg/m2 or higher (obese) or 27 kg/m2 or higher (overweight) with at least one weight-related comorbid condition (eg, hypertension, dyslipidemia, type 2 diabetes mellitus). [162] Use during pregnancy is contraindicated.

Topiramate, which was first licensed as an adjunctive antiepileptic agent, has been associated with profound weight loss (an average of 5-7% of initial weight). The amount of weight loss appears to be greater with higher baseline weights. The exact mechanism of this effect is being actively investigated. Although the degree of efficacy is exciting, the propensity for adverse effects, especially CNS effects such as drowsiness, paresthesias, memory loss, and confusion, is cause for concern.

This combination drug contains an extended-release form of topiramate. In addition, the dose of topiramate in this product (46 mg, although a 92-mg dose form is available for select patients) is lower than those used for seizure management (usually 200 mg twice daily).

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!