desvenlafaxine will boost the amount or result of codeine by influencing hepatic enzyme CYP2D6 metabolism. Use Warning/Keep an eye on. Desvenlafaxine inhibits CYP2D6; with bigger desvenlafaxine doses (ie, four hundred mg) minimize the CYP2D6 substrate dose by nearly fifty%; no dosage adjustment required with desvenlafaxine doses seven consecutive t