Rimonabant: the evidence for its use in the treatment of obesity and the metabolic syndrome

INTRODUCTION: Obesity and overweight affect over 1 billion people worldwide and are leading causes of morbidity and mortality. Clinical features of obesity converge with those of the metabolic syndrome and type 2 diabetes, greatly increasing the risk of long-term adverse outcomes. AIMS: To review the evidence on rimonabant, a novel CB1 receptor antagonist, for the treatment of obese and overweight patients. EVIDENCE REVIEW: There is clear evidence that rimonabant 20 mg/day in conjunction with a hypocaloric diet causes a mean weight loss of 4.6 kg in obese and overweight patients after 1 year’s treatment, with approximately 50% of patients achieving a weight loss of ≥5%. One study demonstrated that weight loss is maintained for up to 2 years. The drug also improves lipid and glycemic cardiovascular risk factors, including high-density lipoprotein cholesterol and insulin resistance, and reduces waist circumference, thus reducing the prevalence of metabolic syndrome. Treatment of obese and overweight diabetic patients with rimonabant decreases glycosylated hemoglobin (HbA(1c)), including patients previously untreated for diabetes. The effect of rimonabant appears to be partly independent of weight loss. Rimonabant 20 mg/day is generally well tolerated, with mild to moderate transient adverse effects including nausea, diarrhea, dizziness, and anxiety. Approximately 14% of patients receiving rimonabant 20 mg/day discontinued due to adverse effects, primarily depressed mood, although overall rates of depression did not differ significantly compared with placebo. PLACE IN THERAPY: The evidence supports the use of rimonabant 20 mg/day along with dietary modification to reduce cardiovascular risk factors in obese and overweight patients, including those with diabetes. The drug is contraindicated in patients receiving antidepressants. Long-term data on cardiovascular outcomes, morbidity, and mortality are eagerly awaited.