Around 63% of Australian adults are overweight or obese, significantly increasing their risk of disease such as cardiovascular disease, type 2 diabetes, and some cancers. Contrave® is a new medication for weight management as an adjunct to diet and exercise. It is indicated for adults who are obese and adults who are overweight and have at least one weight-related comorbidity. Contrave® contains the opioid antagonist, naltrexone, in combination with the dopamine and noradrenaline reuptake inhibitor, bupropion.
A randomised, double-blind, placebo-controlled trial demonstrates the efficacy of this combination therapy. Weight loss of at least 5% was achieved in 31% of participants taking bupropion with naltrexone compared to 12% in the placebo group. Weight loss of at least 10% and 15% was observed in 17% and 9% of the treatment group respectively (5% and 2% for placebo). Significant improvements were also observed in waist circumference, insulin resistance, and lipid levels.
In clinical trials, twice as many people discontinued Contrave® therapy due to adverse events compared to placebo. The most commonly reported reactions leading to discontinuation were nausea, headache, dizziness, and vomiting. As bupropion is associated with a dose-related risk of seizures, Contrave® is contraindicated in patients with a history of seizures. Caution should also be exercised in patients with risk factors for seizures such as a history of head trauma, excessive alcohol use, use of medications that may induce hypoglycaemia, and concomitant use of drugs that may lower the seizure threshold.
- Contrave® (naltrexone hydrochloride and bupropion hydrochloride) Australian approved product information. Chatswood: iNova Pharmaceuticals. Approved August 2018.
- Greenway FL, Fujioka K, Plodkowski RA, Mudaliar S, Guttadauria M, Erickson J, et al. Eﬀect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.