The drug, made by Sanofi-Aventis, is approved for sale in Britain and elsewhere in the European Union but was rejected by a U.S. Food and Drug Administration panel in June 2007 because of concerns the drug increases the risk of depression and suicidal thoughts.
If coupled with exercise, the drug could help patients lose up to 10 percent of their body weight. It is already used by thousands of severely overweight Britons who cannot take other weight-loss treatments. The drug, which won a licence in Europe from the European Medicines Evaluation Agency (EMEA) in June 2006, is also said to help people stop smoking.
Rimonabant is a selective cannabinoid (CB1) receptor antagonist which works by reducing people's appetite for food. It is the first selective CB1 receptor blocker to be approved for use anywhere in the world.
The diet drug works on parts of the brain and thus appears to increase anxiety and depression in people who are prone to such conditions. It is not prescribed to people who suffer from severe depression or other mental health problems. It has been linked to the deaths of five patients, including one suicide.
According to NICE, patients must not be put on the drug if they have any history of depression or anxiety, and they must be carefully monitored. Also, they must have tried or been considered for one of the two drugs orlistat (Xenical) or silbutramine (Reductil), that are more commonly in use in the NHS.
Research suggests one out of 10 people using the drug might develop mental side-effects including low mood and depression, anxiety, irritability, nervousness and sleep disorders. As of 2008, the drug was available in 56 countries.
