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Strong opioid analgesic, controlled medicine

Morphine: uses, side effects & precautions

Also known as MST Continus, Oramorph, Sevredol, Kadian, MS Contin.

Esta información es solo orientativa de carácter general y no constituye un consejo médico. Consulta siempre a un profesional sanitario cualificado para cualquier asunto médico personal. En caso de emergencia, llama al número de emergencias de tu zona.

What it is used for

  • Severe pain, such as after major surgery, serious injury or heart attack
  • Cancer pain and other severe long-term pain
  • Breathlessness in palliative care, under specialist guidance

How it works

Morphine binds to opioid receptors in the brain and spinal cord, strongly reducing the perception of pain and the distress associated with it.

How it is taken

Available as immediate-release and modified-release tablets and capsules, oral solution, and injections used in hospital and palliative care. It is a strong controlled medicine and must be taken exactly as prescribed. Modified-release forms are swallowed whole. It is closely supervised by clinicians who adjust the dose to the individual.

No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.

Common side effects

  • Constipation (very common and often persistent)
  • Nausea and vomiting
  • Drowsiness
  • Dizziness, dry mouth or sweating

Serious effects — get help

  • Slow or shallow breathing (a life-threatening emergency, especially in overdose or with sedatives or alcohol)
  • Severe drowsiness, confusion or unresponsiveness
  • Serious allergic reaction
  • Very low blood pressure
  • Signs of dependence and, if stopped abruptly, withdrawal

If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.

Interactions to watch

  • Alcohol and other sedatives, sleeping tablets or tranquillisers (dangerous breathing depression)
  • Other opioids
  • Some antidepressants and medicines affecting the nervous system
  • Medicines that increase drowsiness or constipation

Who should take care

  • Used only under close medical supervision because of the risk of life-threatening breathing problems and dependence
  • Avoid alcohol; do not drive until you know how it affects you
  • Tell your doctor about breathing problems, head injury, bowel problems, and kidney or liver disease
  • Use in pregnancy or breastfeeding only when a specialist judges it necessary
  • Do not stop suddenly after regular use; seek emergency help immediately for slow breathing or unresponsiveness

Frequently asked questions

Is morphine only for cancer pain?
No. It is used for many kinds of severe pain, including after surgery or serious injury, as well as in cancer and palliative care. A clinician decides when it is appropriate.
Will I become addicted?
When used appropriately under medical supervision for genuine severe pain, the risk is managed carefully. Dependence can develop, so it is monitored and adjusted by your care team.
Why is constipation so common?
Opioids slow the bowel, so most people on morphine need a laxative. Your care team usually prescribes one alongside it.
What should I do if breathing slows?
Very slow or shallow breathing is a medical emergency. Call emergency services immediately; an antidote (naloxone) can reverse opioid effects.
Is Morphine safe to take?
For most people it is safe when taken exactly as a doctor or pharmacist advises and as printed on the label. Tell your clinician about your other medicines and health conditions, and seek urgent care for any serious reaction.

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