[Medication of the month. Rimonabant (Acomplia): first CB1 receptor antagonist of the endocannabinoid system]

Rimonabant (Acomplia) is the first selective CB1 receptor blocker of the endocannabinoid system. Clinical trials showed that, compared to placebo, rimonabant 20 mg/ day consistently increases weight loss, reduces waist circumference, improves atherogenic dyslipidaemia (low HDL cholesterol, high triglycerides, high small dense LDL), diminishes insulin resistance, reduces HbA1c levels, and contributes to lower blood pressure and C-reactive protein levels. Almost half of the most important metabolic effects occur beyond weight loss, suggesting direct peripheral effects of rimonabant, especially in visceral adipose tissue as suggested by the increase in adiponectin levels. Rimonabant at a daily dose of 20 mg is indicated as an adjunct to diet and exercise for the treatment of obese patients, or overweight patients with associated risk factor(s) such as type 2 diabetes or dyslipidaemia. Adverse effects concern digestive tract (nausea, mostly transient) and psychological disorders (depressed mood, anxiety), in relation to the mechanism of action of the drug. Therefore, rimonabant is contra-indicated in case of depression and/or in patients receiving antidepressants.