Medications that inhibit CYP2D6 activity, like paroxetine and quinidine, could result in decreased clearance of oxycodone which could lead on to an increase in oxycodone plasma concentrations. Concurrent administration of quinidine resulted in a rise in oxycodone Cmax by 11%, AUC by thirteen%, and t½ elim.Ritonavir or lopinavir/ritonavir enormousl