Naltrexone/bupropion: an Investigational Combination for Weight Loss and Maintenance

Naltrexone/bupropion is an investigational combination for weight loss and maintenance in patients who are obese or have a BMI ≥ 27 kg/m(2) with comorbid diabetes, hypertension or hyperlipidemia. Pooled results from four phase 3 trials reveal placebo-subtracted mean weight loss of 4.7% (range 3.2-5.2%) with naltrexone/bupropion after 1 year (p < 0.001 vs. placebo in each trial). The placebo-subtracted proportion of patients achieving ≥5% weight loss with naltrexone/bupropion ranged from 26 to 33% (p < 0.001 vs. placebo in each trial). In the majority of phase 3 trials, naltrexone/bupropion significantly improved proportion of patients achieving ≥10% weight loss, waist circumference, triglycerides, high-density lipoprotein, fasting insulin, insulin resistance, and obesity-specific quality of life compared to placebo. In patients with diabetes, naltrexone/bupropion therapy decreased hemoglobin A1c (HbA1c) approximately 0.5% more than placebo (p < 0.001). Common side effects associated with naltrexone/bupropion include nausea, constipation, vomiting, dizziness, and dry mouth. Greater improvement in systolic blood pressure and pulse were seen with placebo compared to naltrexone/bupropion (p < 0.001). Further studies are necessary to determine the effect of naltrexone/bupropion on cardiovascular outcomes. The safety and efficacy of naltrexone/bupropion in weight management is reviewed in this article.