Obesity is a chronic condition associated with a high cardiovascular risk. Abdominal obesity in particular increases the risk of diabetes, heart attacks and early death. This risk is greatly increased in those who smoke.
Rimonabant is a new anti-obesity drug which has been developed by Sanofi-Aventis, a large pharmaceutical company. If you are overweight this drug may help you lose weight.
Rimonabant works by blocking certain chemical pathways within the brain which make you feel hungry. The drug binds to special chemical receptors in the brain known as endocannabinoid receptors. This binding renders these receptors unresponsive to stimulation by chemicals known as ‘cannabinoids’.
Cannabinoids are known to stimulate hunger and cause craving for food. It is known that Marijuana stimulates cannabinoid receptors making users ravenously hungry.
In other words it should help suppress your appetite. The end result is you eat less and lose weight.
This is not known as yet. In clinical trials volunteers who took Rimonabant lost up to 20 pounds in weight over the course of a year. A drop in waistline measurement was also observed.
Most of the weight loss has been shown to occur during the first year of use.
There may be an added benefit in those who smoke. Rimonabant may control the urge to smoke. In one study the drug was shown to double the chances of a smoker quitting successfully, at least short term.
Rimonabant may also help reduce the level of fats in the blood.
Obesity is known to be linked to a higher cardiovascular risk. To date there are no trials which demonstrate benefits in terms of cardiovascular outcomes. In other words we do not know if taking this drug will help you live longer !
Rimonabant will be available as oral tablets and the recommended dose is 20 mg daily.
Side effects observed during the trials include nausea, dizziness, anxiety and painful joints. A full list of side effects will be available when the drug is prescribed to you. We do not know as yet if there will be any influence on the mental state as the endocannabinoid system is yet to be fully evaluated.
Data available shows that it is safe and well tolerated with up to two years use. Long term safety data is not available.
This is a decision for your doctor when the drug becomes available. It is thought that patients with abdominal obesity who have a high cardiovascular risk or type 2 diabetes would be more likely to benefit. If smoking co-exists this may be an added indication.
People with a history of psychiatric illness should use only under specialist supervision.
Rimonabant was launched in the UK in June 2006 and is now available for prescription by hospital Consultants and GPs. The drug currently awaits NICE approval the National Institute for Clinical Excellence which evaluates all drugs before they are available for prescription on the NHS.
The NHS cost of a year's supply of Rimonabant is estimated to be in the region of £700 per patient based on a prescription of a 20mg dose daily for one year.
Dr Nishan Wijenaike MD, FRCP
Consultant Physician (Diabetes and Endocrinology)
West Suffolk Hospitals NHS Trust
Bury St Edmunds
May 2006 (updated Jan. 2007)