desvenlafaxine will improve the stage or outcome of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Keep track of. Desvenlafaxine inhibits CYP2D6; with better desvenlafaxine doses (ie, four hundred mg) reduce the CYP2D6 substrate dose by as many as fifty%; no dosage adjustment needed with desvenlafaxine doses 7 consecutive times … Read More