Dr. Janet Woodcock, director of the FDA Center for Drug Evaluation and Research, said Qsymia contains phentermine and topiramate in an extended-release formula, which should be used in addition to a reduced-calorie diet and exercise.
The drug is approved for use by adults with a body mass index of 30 or greater, or obese, or adults with a BMI of 27 or greater, overweight with at least one weight-related condition such as high blood pressure, type 2 diabetes or high cholesterol, Woodcock said.
Two randomized, placebo-controlled trials involved about 3,700 obese and overweight patients with and without significant weight-related conditions, who were treated for one year. All patients received lifestyle modifications of reduced calorie diet and regular physical activity.
The recommended daily dose of Qsymia was 7.5 milligrams of phentermine and 46 mg of topiramate extended-release, but there is a higher dose too. Patients had an average weight loss of 6.7 percent with the lower dose and 8.9 percent with the higher dose, the trials found.
Qsymia must not be used at any time during pregnancy because it can cause birth defects. In addition, the drug should not be used in patients with glaucoma or hyperthyroidism.
"Qsymia can increase heart rate; this drug's effect on heart rate in patients at high risk for heart attack or stroke is not known," the FDA said. "The use of Qsymia in patients with recent or unstable heart disease or stroke is not recommended."