Grapefruit Juice (GFJ)- I had toyed with the idea of working with grapefruit juice for a long period but have go through blended stories. Just lately I browse that it would not inhibit CYP2D6 but rahter 3A4 that's chargeable for conversion of codeine into norcodeine. In concept by inhibiting 3A4 you leave a lot more codeine for 2D6 to become morphi