7, 8, 14, 21, 235, 10, 15, 19, 2421, 2532211, 17, 20Liver cellElimination via bileUGT2B7NormorphineUGT1A1Codeine-6-glucuronideUGT1A1ABCB1CodeineMorphineUGT2B7Morphine-6-glucuronideCYP2D6ABCC2ABCC3Morphine-3-glucuronideCYP3A4NorcodeineSLCO1B1UGT2B7Codeine-6-glucuronideCYP2D7P1Morphine-6-glucuronideMorphine-3-glucuronide9, 13131, 2, 4, 12, 16718