Samtidig anvendelse af andre midler, der deprimerer centralnervesystemet, fx andre opioider, sedativer eller hypnotika, bedøvelsesmidler, phenothiaziner, beroligende midler, afslapningsmidler til bevægeapparatet, beroligende antihistaminer og alkohol kan forstærke den deprimerende virkning.
The concomitant use of other central nervous system depressants, including other opioids, sedatives or hypnotics, general anaesthetics, phenothiazines, tranquilizers, skeletal muscle relaxants, sedating antihistamines, and alcoholic beverages, may produce additive depressant effects.