Qsymia

Qsymia is a prescription weight-management medication approved for chronic weight management in adults. It is a fixed-dose combination of phentermine, a central nervous system stimulant that suppresses appetite, and topiramate, an anticonvulsant with additional weight-loss effects. It is intended to be used with a reduced-calorie diet and increased physical activity.

Indications and dosing: It is indicated for adults with BMI ≥30, or ≥27 with weight-related conditions such as hypertension, dyslipidemia, or type 2 diabetes. The product is taken once daily in the morning to reduce the risk of insomnia. Dosing starts at a low dose and is titrated to a maintenance dose of one of three strengths: 7.5/46 mg, 11.25/69 mg, or 15/92 mg, depending on response and tolerance. The titration schedule generally spans several weeks.

Mechanism and effects: Phentermine suppresses appetite through central mechanisms; topiramate contributes to weight loss by appetite reduction and changes in taste, satiety, and energy balance. Together they produce modest weight loss in many patients when combined with diet and exercise. Some improvements in blood pressure, triglycerides, and glucose may accompany weight loss.

Safety and precautions: Qsymia is a Schedule IV controlled substance in the United States. It carries a boxed warning regarding fetal harm; pregnancy must be avoided, with pregnancy testing prior to and during treatment. Contraindications include hypersensitivity to phentermine or topiramate, glaucoma, pregnancy, and concomitant use with monoamine oxidase inhibitors. It can cause tachycardia, increased blood pressure, cognitive effects, paresthesias, and metabolic disturbances; discontinue if serious adverse effects occur. It should not be used in people with certain cardiovascular conditions or for those unable to adhere to contraception.