By Sean Kelley
THURSDAY, July 23, 2009 (Health.com) — An experimental drug making its way through clinical trials not only shows promise in helping obese patients lose weight, but it also may improve blood sugar in those who are obese and have type 2 diabetes.
Orexigen Therapeutics plans to seek approval from the Federal Drug Administration in the first half of 2010 for Contrave, a drug that combines naltrexone, which is used to treat alcohol and drug addictions, and bupropion, which is used to fight seasonal affective disorder and depression, and as a smoking cessation drug. According to Orexigen, the combination was chosen "in order to block compensating mechanisms that attempt to prevent long-term, sustained weight loss."
The medication comes in three different dosages, including one called Contrave32. Contrave32 has 360 milligrams of bupropion and 32 mg of naltrexone. Other versions of the drug contain the same amount of bupropion and more or less naltrexone; Contrave16 contains 16 mg of naltrexone, and Contrave48 contains 48 mg of naltrexone.
The company recently announced that in one trial of 505 obese people with type 2 diabetes, 45% of patients taking Contrave32 lost at least 5% of their body weight compared to patients in a placebo group; only 19% of the placebo group lost at least 5% of their body weight.
People with type 2 diabetes who took Contrave seemed to have an improvement in blood sugar control, compared with those who did not take the drug. Patients on Contrave saw their HbA1c, a test used to measure blood sugar, drop 0.6%. People in the placebo group with diabetes only saw a 0.1% drop in HbA1c.
Weight loss in type 2 diabetics can often improve blood sugar control. It's unclear if the drug itself, or the weight loss, resulted in lower levels of blood sugar.
The company conducted three trials—each for 56 months—with different groups, including a total of more than 4,500 patients. There were seven serious adverse outcomes attributed to the drug during the trial: cholecystitis, an inflammation of the gallbladder; seizures; heart palpitations; paresthesia, tingling or numbness of the skin; and vertigo. Other side effects experienced by a small percentage of the Contrave groups, but less than 1% of the placebo groups, included nausea, headaches, and dizziness.