Morphine (C17H19NO3) is a powerful analgesic narcotic drug found in opium. Like other opiates, morphine acts directly on the central nervous system (CNS) to relieve pain, and at synapses of the arcuate nucleus, in particular. Side effects include impairment of mental performance, euphoria, drowsiness, lethargy, and blurred vision. It also decreases hunger, inhibits the cough reflex, and produces constipation. Morphine is usually highly addictive, and tolerance and physical and psychological dependence develop quickly.

Morphine is frequently found in various preparations. Parenterally, it is given as subcutaneous, intravenous or epidural injections. The military sometimes issues morphine loaded in an autoinjector. Orally, it comes as an elixir or in tablet form. Morphine is rarely in suppository form.

Morphine is indicated in:

  • relief of acute, severe pain
    • pain after surgery
    • pain associated with trauma
  • relief of moderate to severe chronic pain
    • cancer pain
  • as an adjunct to general anesthesia
  • in epidural anesthesia

It was first isolated in 1803 by the German pharmacist Friedrich Wilhelm Adam Serturner, who named it 'morphium' after Morpheus, the Greek god of dreams. But it was not until the development of the hypodermic syringe (1853) that its use spread. It was used for pain relief and, ironically, as a 'cure' for opium or alcohol addiction. Its extensive use during the American Civil War resulted in over 400,000 sufferers from the 'soldiers disease' (addiction).

Heroin was derived from morphine in 1874. Along with other drugs, its possession without a prescription was criminalised in the US by the Harrison Narcotics Tax Act of 1914.

There is an early 1990s rock band named Morphine.