Review by U.S. Food and Drug Administration staffs documented that diet pill Qnexa is effective for weight loss and can bring improvements in weight-related co-morbidities such as hypertension, type 2 diabetes, and dyslipidemia.

Vivus’ Qnexa is a combination of FDA approved drugs phentermine and topiramate in low doses. The combination is found to produce weight loss that meets the FDA’s criteria for approval of obesity drugs.

Qnexa is one of 3 weight loss drugs submitted to FDA for approval this year. Qnexa showed the best weight loss results in clinical trials compared with Locaserin and Contrave. Safety and tolerability of the diet pills is a concern and the issue for Qnexa will be discussed during the FDA advisory panel meeting on Thursday.

Side effects of Qnexa include paresthesia, dry mouth, constipation, upper respiratory tract infection and headache. Although all three low, mid and top doses were safe and generally well tolerated by study subjects, some had to drop out of the study due to adverse side effects such as memory and concentration problems.

Over two thirds of adults in the U.S. are obese or overweight and the rate seems to be increasing. The health consequences and health care cost of obesity will likely increase as well.

If approved, Qnexa will be the first weight loss drug in a decade. As with all obesity drugs, Vivus advises that for treatment of obesity, Qnexa should be taken in conjunction with diet and exercise.