Advisory panel votes against Qnexa

An FDA advisory panel recommended against approving (10-7 vote) the combination weight-loss drug Qnexa^® (phentermine/topiramate) because of concerns about safety. The drug appears to be effective at inducing weight loss, but is associated with significant side effects including depression, anxiety, sleep disorders, attention, memory, and language and other cognitive disorders, as well as metabolic acidosis, increased heart rate, and teratogenicity. Qnexa is a combination of two available drugs and both remain on the market individually. Phentermine was approved in 1959 and is currently indicated as short-term treatment for weight reduction. It was part of the infamous Fen/Phen combination along with fenfluramine (later dexfenfluramine; both fenfluramine and dexfenfluramine were eventually removed from the market when they were found to cause pulmonary hypertension and cardiac valvulopathy). Topiramate is approved for the treatment of seizures and migraine prophylaxis. The FDA generally follows the recommendations of its expert panels.