Morphine (INN) (IPA: [ˈmɔ(ɹ)fin]) is a strong opiate pain killer drug. It is the principal active agent in opium and the prototypical opiate. Like other opioids, e.g. diacetylmorphine (heroin), morphine acts directly on the central nervous system (CNS) to relieve pain, and at synapses of the nucleus accumbens in particular. Morphine is highly addictive when compared to other substances, and tolerance and physical and mental dependences develop very rapidly.
Patients on morphine sometimes say they have insomnia, visual hallucinations and nightmares;[1] if these occur then reduction in dosage or switch to an alternative opioid analgesic should be considered.
The word "morphine" is derived from Morpheus, the god of dreams in Greek mythology. He is the son of Hypnos, god of sleep.