May potentially enhance or prolong effects w/ macrolide antibiotics (eg, erythromycin), azole antifungals (eg, ketoconazole, itraconazole) or certain PIs (eg, ritonavir). Increased CNS depressant effects w/ CNS depressants eg, other morphine derivatives (analgesics & antitussives), general anaesth, skeletal muscle relaxants, sedative antidepressants, sedative H1
antihistamines, barbiturates, anxiolytics (ie, benzodiazepines), hypnotics, antipsychotics, clonidine & related substances. Potentiation of sedative effects w/ alcohol. Severe & unpredictable potentiation w/ MAOIs. Antagonism & induce w/drawal symptoms w/ partial opioid agonists/antagonists (eg, buprenorphine, nalbuphine, pentazocine). May increase risk of serotonin syndrome w/ SSRI or SNRI or MAOI.