desvenlafaxine will raise the stage or outcome of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Check. Desvenlafaxine inhibits CYP2D6; with bigger desvenlafaxine doses (ie, four hundred mg) lessen the CYP2D6 substrate dose by nearly fifty%; no dosage adjustment essential with desvenlafaxine doses 7 consecutive times promptly pr