Rimonabant is a commonly prescribed CB1 cannabinoid receptor antagonist that works by reducing your appetite therefore helping you to lose weight fast and efficiently. The following medicines are never supposed to be combined with rimonabant unless your doctor is aware of that: clarithromycin, phenobarbital, itraconazole, ritonavir, carbamazeptine, ketaconazole, nefazodone, telithromycin, and phenytoin. You may need a dose adjustment or your doctor will monitor you for side effects when you are using rimonabant in combination with any of the medicines mentioned. Your doctor needs to be notified of any of the following side effects in case they last for too long or bother you too much: dry mouth, irritability, anorexia, impaired memory, nervousness, anxiety, diarrhea, nausea, sleep disorders, depressions, and sometimes vomiting. You will need to be very careful when taking this medicine and avoid using more of it than prescribed. Taking more of rimonabant is not going to make your treatment more efficient and can lead to an overdose. An overdose of rimonabant is supposed to be reported to your local emergency center, especially if you get such symptoms as fatigue, insomnia, headache, and euphoria.