desvenlafaxine will boost the amount or outcome of codeine by impacting hepatic enzyme CYP2D6 metabolism. Use Warning/Observe. Desvenlafaxine inhibits CYP2D6; with greater desvenlafaxine doses (ie, 400 mg) lower the CYP2D6 substrate dose by as much as fifty%; no dosage adjustment desired with desvenlafaxine doses 7 consecutive times right away ahea… Read More