Enhanced sedative effect w/ alcohol. Enhanced central depressive effect w/ CNS depressants. Enhanced euphoric effect of benzodiazepines & benzodiazepine-like agents w/ narcotic analgesics. Enhanced activity of benzodiazepines & benzodiazepine-like agents w/ CYP450 inhibitors. Increased plasma levels w/ erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir. Decreased plasma levels w/ rifampicin, carbamazepine, phenobarb, pheytoin, St. John's wort. Co-administration w/ antipsychotics (neuroleptics), hypnotics, anxiolytics/sedatives, antidepressants, narcotic analgesics, anti-epileptics, anaesth & sedative antihistamines.