Samtidig anvendelse af andre CNS- depressiva såsom andre morfinderivater (analgetika og antitussiva), universel anæstesi, skeletmuskelrelaksantia, sedative antidepressiva, sedative H1 - antihistaminer, barbiturater, anxiolytika (dvs. benzodiazepiner), hypnotika, antipsykotika, clonidin og beslægtede stoffer kan fremkalde øgede CNS dæmpende virkninger.
Concomitant use of other CNS depressants, such as other morphine derivatives (analgesics and antitussives), general anaesthetics, skeletal muscle relaxants, sedative antidepressants, sedative H1 antihistamines, barbiturates, anxiolytics (ie benzodiazepines), hypnotics, antipsychotics, clonidine and related substances may produce increased CNS depressant effects.