Morphine (Oramorph / Sevredol / Morcap SR / Morphegesic SR / MST Continus / MXL / Zomorph)

Morphine (Oramorph / Sevredol / Morcap SR / Morphegesic SR / MST Continus / MXL / Zomorph) is an extremely powerful painkilling drug that is produced by opium poppies. It also inhibits coughing and diarrhoea. It is used medically to relieve the severe pain caused by surgery, cancer, kidney stones and injury.

Morphine acts by stimulating mu-opioid receptors on the surface of nerve cells in the brain and spinal cord. These inhibit pain signals, as well as producing euphoric and sedative effects. Side-effects of morphine include impaired mental performance, drowsiness, blurred vision, reduced appetite and constipation. It can also cause insomnia and nightmares. In high doses, it can inhibit breathing.

Morphine is a highly addictive drug, and is abused as opium. However, morphine is unlikely to cause physical dependence when used medically.

Morphine is given by injection under the skin, into a vein or around the spinal cord (epidurally). Versions of morphine that are taken by mouth are also available, but this is less effective than injected morphine: however, oral morphine, particularly slow-release versions, are more convenient for patients to take at home.1

Test tube studies have found that morphine can impair the activity of anti-HIV immune cells, lead to the death of brain cells, increase the ability of HIV to infect white blood cells and stimulate viral replication.2 3 4 5 6 In addition, studies carried out in monkeys infected with simian and simian-human immunodeficiency virus (SIV / SHIV) have suggested that morphine can increase viral replication and HIV disease progression in the blood and the brain, particularly after repeated exposures to the drug.7 8 However, these effects have not been observed in human studies.

Morphine levels may be reduced by protease inhibitors, but this remains to be studied.


  1. Dixon P et al. AIDS and cancer pain treated with slow release morphine. Postgrad Med J 67: S92-S94, 1991
  2. Wang X et al. Morphine inhibits CD8+ T cell-mediated, noncytolytic, anti-HIV activity in latently infected immune cells. J Leukoc Biol 78: 772-776, 2005
  3. Hu S et al. Morphine potentiates HIV-1 gp120-induced neuronal apoptosis. J Infect Dis 191: 886-889, 2005
  4. Li Y et al. Morphine enhances HIV infection of neonatal macrophages. Pediatr Res 54: 282-288, 2003
  5. Guo CJ et al. Morphine enhances HIV infection of human blood mononuclear phagocytes through modulation of beta-chemokines and CCR5 receptor. J Investig Med 50: 435-442, 2002
  6. Peterson PK et al. Morphine promotes the growth of HIV-1 in human peripheral blood mononuclear cell cocultures. AIDS 4: 869-873, 1990
  7. Kumar R et al. Modulation by morphine of viral set point in rhesus macaques infected with simian immunodeficiency virus and simian-human immunodeficiency virus. J Virol 78: 11425-11428, 2004
  8. Kumar R et al. for the International Studies of HIV/AIDS (ISHA) Investigators. Trends in HIV-1 in young adults in south India from 2000 to 2004: a prevalence study. The Lancet 367: 1164–72, 2006

Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.