desvenlafaxine will increase the level or impact of codeine by impacting hepatic enzyme CYP2D6 metabolism. Use Warning/Keep an eye on. Desvenlafaxine inhibits CYP2D6; with bigger desvenlafaxine doses (ie, 400 mg) lower the CYP2D6 substrate dose by as much as fifty%; no dosage adjustment wanted with desvenlafaxine doses 7 consecutive days straight a… Read More