Glucuronidation in the liver produces an active metabolite of the drug, morphine-6-glucuronide (morphine-3-glucuronide is also formed). Metabolites are then excreted in the urine. Enterohepatic circulation of morphine does occur, but this is not clinically important. | Glucuronidation in the liver produces an active metabolite of the drug, morphine-6-glucuronide (morphine-3-glucuronide is also formed). Metabolites are then excreted in the urine. Enterohepatic circulation of morphine does occur, but this is not clinically important. |