Enhanced sedative effect w/ alcohol. Enhancement of central depressive effect w/ antipsychotics, hypnotics, anxiolytics/sedatives, antidepressants, narcotic analgesics, antiepileptics, anaesth & sedative antihistamines. Increased blood levels w/ fluvoxamine, ciprofloxacin. Enhanced euphoria w/ narcotic analgesics. Increased risk of sedation, resp depression, coma & death w/ opioids. Enhanced activity w/ CYP450 inhibitors. Decreased pharmacodynamic effect w/ CYP3A4 inducer eg, rifampicin & St. John's Wort. Prolonged elimination t
½, increased total AUC, & decreased apparent oral clearance w/ ketoconazole (potent CYP3A4 inhibitor).