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Generic Name: rimonabant
Company: Sanofi-Aventis

Sanofi-Aventis has withdrawn rimonabant from the market globally and it is no longer under development.1 Acomplia was officially withdrawn by the European Medicines Agency (EMEA) in January 2009 due to the risks of dangerous psychological side effects, including suicidality. Previously, the EMEA had suspended Acomplia from the UK market in 2008 because the agency felt the benefits did not outweigh the risks. In June of 2007, the FDA's Endocrine and Metabolic Drugs Advisory Committee recommended against the approval of rimonabant (known in the United States as Zimulti) due to concerns over similar serious side effects. Subsequently, the FDA did not approve rimonabant, and it has never been marketed in the United States.

What is Acomplia?

  • Acomplia (rimonabant) was the first in a new class of therapeutic agents called Cannabinoid-1 Receptor Blockers (CB1).
  • Acomplia was studied for use in the treatment of obesity and related conditions.

How does Acomplia work?

  • Acomplia acts by selectively blocking CB1 receptors found in the brain and in peripheral organs important in glucose and lipid (or fat) metabolism, including adipose tissue, the liver, gastrointestinal tract and muscle2.
  • Acomplia switches off the same brain circuits that make people hungry when they smoke cannabis.
  • CB1 receptor blockade with Acomplia acts to decrease the overactivity of the endocannabinoid system (EC system).3,4 The EC system is a recently characterised physiological system that includes receptors such as the CB1 receptor and it has been shown to play an important role in regulating body weight and in controlling energy balance, as well as glucose and lipid (or fat) metabolism.

What is Acomplia used for?

  • Acomplia was studied to be used complementary to diet and exercise to treat obese or overweight patients who suffer from type 2 diabetes and abnormal levels of fat in the blood.
  • Sanofi argued that Acomplia could also prevent the risk of cardiovascular disease.
  • Patients with large waist circumference (102 cm in men and 88 cm in women) were said to most benefit from taking the drug.

Does Acomplia also aid smoking cessation?

  • Acomplia (Zimulti in the US) was studied by Sanofi-Aventis as an aid to smoking cessation based on studies for up to one year in over 6,500 smokers motivated to quit smoking.
  • Sanofi-Aventis submitted a New Drug Application to the FDA, which in turn issued a non-approvable letter for Zimulti for use in smoking cessation. In June of 2007, the FDA's Endocrine and Metabolic Drugs Advisory Committee recommended against the approval of rimonabant due to concerns over serious side effects such as suicidality.

What were the results of Acomplia clinical trial studies?

  • In clinical studies, Acomplia was has been shown to improve a wide array of cardiometabolic risk factors as well as promoting sustained weight loss.5,6
  • Approximately half of the observed improvement in HDL-cholesterol, triglycerides and HbA1C (an indicator of blood sugar control) in patients who received Acomplia 20mg was beyond that expected from weight loss alone.7
  • Serious psychological adverse effects, such as suicidality and depression led to the eventual global withdrawal of rimonabant by Sanofi-Aventis.


  1. Personal Communication. Sanofi-Aventis Medical Information Department. Rimonabant availability. September 12, 2011
  2. Pagotto U. Pasquali R. Fighting obesity and associated risk factors by antagonising cannabinoid type 1 receptors. Lancet. 2005; 365: 1363-64.
  3. Van Gaal LF, Rissanen, AM, Scheen AJ, Ziegler O, Rössner S for the RIO-Europe Study Group. Effects of the cannabinoid-1 receptor blocker rimonabant on weight reduction and cardiovascular risk factors in overweight patients: 1-year experience from the RIO-Europe study. Lancet. 2005; 365: 1389-97.
  4. Marzo V, et al. Leptin-regulated endocannabinoids are involved in maintaining food intake. Nature. 2001;410:822-825.
  5. Déspres, J.P. et al. Effect of Rimonabant on Body Weight and the Metabolic Syndrome in Overweight Patients. New England Journal of Medicine, November, 16, 2005.
  6. Van Gaal L, et al. Effects Of The Cannabinoid-1 Receptor Blocker Rimonabant On Weight Reduction And Cardiovascular Risk Factors In Overweight Patients: 1-Year Experience From The RIO-Europe Study. The Lancet. 365;1389-1397.
  7. Acomplia Summary of Product Characteristics


Rimonabant Accepted for Filing By the FDA June 23, 2005

Sanofi-aventis Received from the FDA an Approvable Letter for Rimonabant for Weight Management and a Non Approvable Letter for Smoking Cessation February 17, 2006

Weight Loss Drug Zimulti (rimonabant) Can Cause Serious Physical and Psychological Harm and Birth Defects, Public Citizen Tells FDA June 13, 2007

Sanofi-Aventis to Discontinue Rimonabant Trials for All Indications June 11, 2008

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