Ritonavir or lopinavir/ritonavir drastically raise plasma concentrations of oxycodone in healthy human volunteers resulting from inhibition of CYP3A4 and CYP2D6.[58] Rifampicin drastically lowers plasma concentrations of oxycodone because of strong induction of CYP3A4.Avoid consuming grapefruit or ingesting grapefruit juice whilst working with this… Read More