Selective & non-selective MAOIs. Increased sedative effect w/ alcohol. Reduced efficacy w/ carbamazepine & other enzyme inducers. Decreased analgesic effect w/ opioid agonists-antagonists. SSRIs, triptans; CNS depressants eg, other opioid derivatives, barbiturates, benzodiazepines, other anxiolytics, hypnotics, sedative, antidepressant & antihistamines, neuroleptics, centrally-acting antihypertensive drugs, thalidomide, baclofen; warfarin; ketoconazole, erythromycin.