Rimonabant: Boom to ban

Abstract

Rapidly rising prevalence of obesity and health care cost of its complications necessities need for highly efficacious and safe antiobesity drugs. As most old antiobesity drugs had moderate efficacy, severe toxicity and some of them very costly. Rimonabant, CB1 receptor antagonist was introduced with high expectations. Rimonabant has multiple beneficial effects, apart from significant weight loss it increases HDL and reduces triglycerides, Hb A 1C level, prevalence of metabolic syndrome. This wide spectrum of effects helps in comprehensive management of obesity and associated complications. Cost of rimonabant (generic Rs.5-8 per tablet) is also much lesser than the only other commonly used antiobesity drug orlistat around Rs. 40 per tablet. During trials rimonabant apart from nausea had neuropsychiatric side effects. EMEA approved rimonabant in June 2006 with concern over its psychiatric side effects. In 2007 EMEA contraindicated rimonabant in patients of depression or taking antidepressants. Further analysis in 2008 concluded that the incidence of psychiatric side effects was higher in clinical practice compared to controlled trials also few cases of suicide became a major safety concern, finally leading to suspension of its sale by EMEA in Oct 2008. USFDA never approved rimonabant over safety concerns, while India banned it shortly thereafter as precautionary measure. Present paper deals with the various events during the rapid rise and fall of rimonabant which was widely considered as blockbuster diet pill but was suspended over serious neuropsychiatric side effects.