Additive central depressant effect w/ CNS depressants eg, alcohol, benzodiazepines, barbiturates, sedative/hypnotics, anxiolytics, antidepressant agents (including TCAs, MAOIs), antipsychotics (neuroleptics), phenothiazines, skeletal muscle relaxants, antihistamines, neuroleptics, antiepileptic drugs, narcotic analgesics or anaesth; opioids. Euphoric enhancement w/ narcotic analgesics. Increased risk of somnambulism & associated behaviours w/ alcohol & other CNS depressants. Additive sedative effects w/ imipramine. Decreased alertness & psychomotor performance w/ chlorpromazine. Decreased pharmacodynamic effect w/ CYP3A4 inducers (eg, rifampicin & St. John's Wort). Enhanced sedative effects w/ ketoconazole (CYP3A4 inhibitor). Increased blood levels w/ fluvoxamine (strong CYP1A2 inhibitor & moderate to weak CYP2C9 & CYP3A4 inhibitor); ciprofloxacin (moderate CYP1A2 & CYP3A4 inhibitor).