Abstract
【Case】 We report a 59-year-old man with severe pruritus due to hepatocellular carcinoma who responded to oxycodon. 【Discussion】 Pruritus is sometimes significant clinical problem among advanced cancer patients. The cause of pruritus was still unknown；however, increased endogenous opioids and activation of opioid receptors play an important part in its pathogenesis. Systemic administration of mu opioid receptor agonists, such as oxycodon, for patients without pruritus sometimes produces itching. They bind to the mu opioid receptors but stimulate them less than do endogenous opioids. In this situation of increased endogenous opioidergic tone, they may work as competitive inhibitors in comparison with endogenous opioids. As a result, oxycodon behaved an antipruritic drug. Our observation may lead to a new understanding of pruritus in jaundice due to advanced cancer and to new treatment of pruritus.
