Objective: The combination of 32 mg naltrexone and 360 mg bupropion prolonged release (NB32) was recently approved by both the food and drug administration (FDA) and the European medicines agency (EMA) as an adjunct to a comprehensive lifestyle intervention to achieve weight loss.
Design: Randomized controlled trials with naltrexone/bupropion prolonged release were selected through a search based on PubMed listings using the terms "bupropion AND naltrexone".
Results: NB32 treatment resulted in 5.0-9.3% weight loss, while the placebo-subtracted weight loss was 3.2-5.2% during 56 weeks of treatment. The proportion of treated patients with ≥ 5% weight loss was 45-66%, while the placebo-subtracted proportion was 23-34%. NB32 was associated with a decrease in waist circumference, serum triglycerides and insulin resistance and an increase in high-density lipoprotein-cholesterol (HDL-C). Blood pressure mainly remained stable but there was a small increase in heart rate. The most common side effects were nausea, constipation, headache and vomiting. Serious adverse effects, which were very rare, included suicidal thoughts and seizures. In the majority of patients NB32 treatment was well tolerated.
Conclusions: Naltrexone/bupropion combination appears to be an effective adjunct to a comprehensive lifestyle intervention in order to achieve weight loss and treat obesity-related comorbidities.