General Information

Contrave is  combination of naltrexone, an opioid antagonist, and bupropion, an inhibitor of the neuronal reuptake of dopamine and norepinephrine. 

Contrave is specifically indicated as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index (BMI) of: 30 kg/m2 or greater (obese) or 27 kg/m2 or greater (overweight) in the presence of at least one weight-related comorbidity.

Contrave is supplied as an extended release table for oral administration. Dosing should be escalated according to the following schedule:

Week 1: Morning dose: 1 tablet Evening dose: no tablet

Week 2: Morning dose: 1 tablet Evening dose: 1 tablet

Week 3: Morning dose: 2 tablets Evening dose: 1 tablet

Week 4 - Onward: Morning dose: 2 tablets Evening dose: 2 tablets

Patients using Contrave at the maintenance dose should be evaluated after 12 weeks to determine if the treatment is working. If a patient has not lost at least 5 percent of baseline body weight, Contrave should be discontinued.

Contrave has the potential to cause suicidal thoughts and behaviors and neuropsychiatric reactions.

Mechanism of Action

Contrave is  combination of naltrexone, an opioid antagonist, and bupropion, an inhibitor of the neuronal reuptake of dopamine and norepinephrine. Nonclinical studies suggest that naltrexone and bupropion have effects on two separate areas of the brain involved in the regulation of food intake: the hypothalamus (appetite regulatory center) and the mesolimbic dopamine circuit (reward system). The exact neurochemical effects of Contrave leading to weight loss are not fully understood. 

Side Effects

Adverse effects associated with the use of Contrave may include, but are not limited to, the following:

• nausea
• constipation
• headache
• vomiting
• dizziness
• insomnia 
• dry mouth
• diarrhea

Clinical Trial Results

The FDA approval of Contrave was based on multiple clinical trials that included approximately 4,500 obese and overweight patients with and without significant weight-related conditions treated for one year. All patients received lifestyle modification that consisted of a reduced- calorie diet and regular physical activity.

Results from a clinical trial that enrolled patients without diabetes showed that patients had an average weight loss of 4.1% over treatment with placebo (inactive pill) at one year. In this trial, 42% f patients treated with Contrave lost at least 5 percent of their body weight compared with 17% of patients treated with placebo. Results from another clinical trial that enrolled patients with type 2 diabetes showed that patients had an average weight loss of 2% over treatment with placebo at one year. In this trial, 36% of patients treated with Contrave lost at least 5 percent of their body weight compared with 18% of patients treated with placebo.