Readers know of my admiration for the expert doctors of pharmacology at Prescribers’ Letter. Here are their most recent comments on the two weight loss drugs to be available in the U.S. over the next year.
Qsymia is coming this fall…and Belviq early next year. But don’t expect either one to be a magic bullet.
Qsymia combines low doses of phentermine and extended-release topiramate. It was previously called Qnexa. Qsymia seems to work better than other weight loss drugs. Patients using Qsymia lose an average of 20 pounds in one year…compared to 5 to 10 pounds with other weight loss drugs.
But caution (patients) about impaired cognition, fatigue, dizziness, etc.
Also, Qsymia will have a Risk Evaluation and Mitigation Strategy (REMS) to inform prescribers and patients about the risk of birth defects if topiramate is taken during the first trimester. There will be prescriber training…a patient brochure…and it will initially be available only from specialty pharmacies.
If you prescribe phentermine and topiramate separately for weight loss, be sure to inform women about the risk of birth defects.
Belviq (lorcaserin) is the first serotonin 2C agonist. It targets the satiety center of the brain, helping patients feel full sooner and eat less. Tell patients it’s NOT expected to affect heart valves like fenfluramine. But Belviq is only modestly effective. Patients lose about 7 pounds more in one year with Belviq than with placebo.
Belviq will be a controlled substance…due to a small incidence of euphoria, similar to zolpidem.