Morphine at a glance
Medicine class
Strong opioid analgesic.
Main role
Relief of severe pain requiring an opioid.
Available forms
Oral liquid, orodispersible tablets, prolonged-release tablets or capsules, and injection.
Dependence
Physical dependence and opioid use disorder can develop, including during prescribed use. Do not stop suddenly without advice.
Driving and alcohol
Do not drive if impaired. Alcohol can increase sedation and serious adverse effects.
What is Morphine used for?
Selected UK products are licensed for pain requiring a strong opioid.
Severe or intractable pain requiring prolonged relief.
Moderate to severe pain treated by injection in supervised settings, including pain associated with surgery, cancer or myocardial infarction.
How does Morphine work?
Morphine activates opioid receptors in the brain and spinal cord, particularly mu receptors. This reduces the perception and emotional impact of pain but can also cause sleepiness, slower breathing and reduced bowel movement.
Morphine preparations and strengths
Dispersible tablet
Route: Oral
Strengths: 1 mg, 2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg
How to take Morphine
Follow the label and instructions for the specific formulation because morphine products are not all taken in the same way.
Swallow prolonged-release tablets whole. Breaking, crushing or chewing them can release morphine rapidly and cause a potentially fatal overdose.
MXL prolonged-release capsules may be swallowed whole or opened and sprinkled onto soft, cold food. Do not crush or chew the granules.
Actimorph orodispersible tablets disperse in the mouth before swallowing. Where appropriate, they may instead be dispersed in a small amount of water on a spoon.
Measure oral liquid with the supplied oral syringe or measuring device, not a household spoon.
Injections and patient-controlled analgesia systems must be managed by appropriately trained healthcare staff.
Do not stop regular morphine suddenly. Plan discontinuation with the prescriber to reduce withdrawal risk.
Morphine side effects
Common or expected effects
- Constipation
- Nausea or vomiting
- Sleepiness
- Dizziness
- Confusion
- Headache
- Itching or rash
Get urgent medical advice
- Slow, shallow or difficult breathing
- Extreme sleepiness, inability to wake or loss of consciousness
- Severe allergic reaction with tongue or throat swelling or breathing difficulty
- Severe skin reaction with blistering, peeling or widespread painful rash
- Possible bowel obstruction, including severe abdominal pain with persistent vomiting or inability to pass stool or wind
Morphine in pregnancy
Morphine may be considered when the expected benefit of controlling severe pain outweighs possible risks. Evidence about fetal development is limited. Exposure near delivery or after prolonged use can cause breathing problems or withdrawal in the newborn, so involve the prescriber and maternity team. Some prolonged-release product licences advise against use during pregnancy.
Morphine while breastfeeding
Morphine can be used cautiously after individual assessment and is the preferred strong opioid in UK specialist breastfeeding guidance for healthy, full-term infants. Monitor the baby for unusual sleepiness, poor feeding or weight gain, constipation, pallor or slow breathing. Seek urgent help for breathing difficulty or inability to wake. Advice is especially important for premature or unwell babies and prolonged-release treatment.
Morphine interactions
Check all prescribed, non-prescribed and recreational substances because several combinations increase sedation or alter morphine's effect.
Benzodiazepines and other sedatives
Additive central nervous system depression can cause profound sleepiness, respiratory depression, coma or death.
Gabapentin, pregabalin and other sedating antiepileptics
The combination can increase sleepiness and respiratory depression and requires clinical monitoring.
Alcohol
Increases sedation and the risk of serious opioid adverse effects.
Common questions about Morphine
Answers are fully visible for fast scanning and source review.
Can morphine sulfate cause addiction?
Yes. Dependence and opioid use disorder can occur even when morphine is prescribed. Discuss craving, loss of control or taking extra medicine promptly with the prescriber.
Can I stop morphine sulfate suddenly?
Regular morphine should not usually be stopped suddenly because withdrawal can occur. The prescriber should plan a gradual, monitored reduction.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.