Experimental drug helps diabetes patients lose weight

"This new medication is promising because of the amount of weight loss it produces, the resultant improvement in important risk factors for diabetes, and, particularly in the lower dose studied, in its tolerability," said study lead author Donna H. Ryan, M.D., professor emeritus at Pennington Biomedical Research Center (LSU System) in Baton Rouge, LA.

Diabetes treatment involves weight management and medications to control blood-sugar levels and risk factors. If left untreated, diabetes can increase the danger of developing heart and blood-vessel diseases. Since one of the main risk factors for all of these diseases is obesity, weight loss is important to both prevention and treatment.

Focusing on type 2 diabetes, investigators found that patients who took the experimental weight-loss drug phentermine/topiramate, combined with diet and exercise modifications, were more likely to lose moderate amounts of weight than those who received a sugar-pill placebo and the diet and exercise intervention.

The percentage of study participants losing more than 10 percent of their initial weight while decreasing their blood pressure and hemoglobin A1c, was:

• 14 percent on low-dose phentermine/topiramate
• 31 percent on high-dose phentermine/topiramate
• 4 percent on placebo

Phentermine/topiramate is a combined medication that works by decreasing appetite. The main side effects associated with the drug were constipation and tingling sensations in the fingers. Patients who took phentermine/topiramate were also more likely to develop low blood sugar than those who received placebo.

This study was an analysis of diabetic patients who enrolled in weight-loss studies testing medications given with lifestyle intervention. Investigators randomly assigned 357 patients with type 2 diabetes to receive either low-dose phentermine/topiramate (7.5 milligrams), high-dose phentermine/topiramate (15 milligrams), or placebo. Neither investigators nor patients knew who was receiving the drug versus placebo in the double-blinded study. Participants' average age was 53 years, 66 percent were female, most were white, and their average weight was 222 pounds. Follow-up was one year.

Provided by The Endocrine Society