Morphine (INN) (/Л€mЙ”rfiЛђn/) (sold under nearly a hundred trade names) is an opioid analgesic drug, a recreational drug, and the main psychoactive chemical in opium. In clinical medicine, morphine is regarded as the gold standard, or benchmark, of analgesics used to relieve intense pain and suffering. Like other opioids, such as oxycodone, hydromorphone, and diacetylmorphine (heroin), morphine acts directly on the central nervous system (CNS) to relieve pain.