Rimonabant is an anorectic antiobesity drug approved in Europe in 2006 but was withdrawn worldwide in 2008 due to serious psychiatric side effects; it was never approved in the United States. Rimonabant is an inverse agonist for the cannabinoid receptor C (CB1) and binds with high affinity to central CB1 receptors to reduce appetite and modulate reward pathways; chemically it is a lipophilic, orally active pyrazole-derived antagonist/inverse agonist that undergoes extensive hepatic metabolism with multiple oxidative metabolites, displays good oral bioavailability, and has a prolonged terminal elimination phase consistent with tissue distribution and enterohepatic recycling.
Parent: Rimonabant
Typical quality specifications for rimonabant active pharmaceutical ingredient address process-related and degradation impurities, with individual identified related substances commonly limited to not greater than 0.10 percent w/w and unspecified impurities not greater than 0.05 percent w/w, and a specification for total impurities generally not exceeding 0.5 percent w/w; residual solvents are controlled to ICH limits (for example Class 2 solvents below their ppm limits), heavy metals are controlled to low ppm levels (for example below 10 ppm), and water content is monitored (typically below 0.5 percent) while stability studies define specific degradation products and shelf-life limits.
Rimonabant was developed and used to reduce appetite and promote weight loss in obesity by blocking central CB1 receptor signaling that influences food intake and reward; clinical use was for pharmacological weight management in combination with diet and exercise prior to its market withdrawal.
Rimonabant was withdrawn from use because clinical trial and post-marketing data showed an increased incidence of psychiatric adverse events including severe depression, anxiety, and suicidal ideation, leading regulators to determine that the psychiatric risk outweighed the benefits for weight loss.
Reported side effects include psychiatric disorders such as depression, anxiety, and suicidal thoughts, as well as insomnia, nausea, dizziness, headache, and gastrointestinal complaints; the psychiatric effects were the most serious and were the primary reason for regulatory withdrawal.
No, rimonabant was never approved by the United States Food and Drug Administration and is not available as an FDA-approved medication.
