Strong opioid
Morphine
Morphine sulfate / morphine hydrochloride
Morphine is a strong opioid painkiller used for severe pain that cannot be controlled with weaker medicines. In the UK it is most often used in cancer pain, palliative care and pain after major surgery or serious injury.
How this medicine is supplied
Prescription only in the UK. Dispensed by us only against a valid prescription from a UK prescriber.
How prescriptions workSigns of overdose include pinpoint pupils, extreme drowsiness, slow or shallow breathing and blue lips. Call 999 immediately.
What it is used for
- Severe acute pain, such as after major surgery or a serious injury
- Severe long-term pain, most commonly cancer-related pain
- Breathlessness in palliative care, under specialist supervision
How it works
Morphine attaches to opioid receptors in the brain and spinal cord. This changes how pain signals are received and reduces the distress that comes with severe pain. It does not treat the cause of the pain, so it is usually one part of a wider pain management plan.
Forms available in the UK
- Immediate-release tablets and oral solution
- Modified-release tablets or capsules (taken twice or once a day)
- Injection, used in hospital and palliative settings
- Suppositories
Safety information you must know
- Never crush, chew or open modified-release tablets or capsules. Doing so can release a full day's dose at once and cause a fatal overdose.
- Do not drink alcohol, and do not take sleeping tablets, benzodiazepines or gabapentinoids alongside morphine unless your prescriber has specifically agreed to it. The combination can slow your breathing dangerously.
- Constipation is expected rather than rare. A laxative is normally prescribed at the same time — take it even if your bowels feel normal.
- Do not drive or operate machinery until you know how morphine affects you. It is an offence to drive if your driving is impaired by medicine.
- Store it locked away, never share it with anyone else, and return any unused medicine to a pharmacy for safe disposal.
Common side effects
- Drowsiness and dizziness, especially when starting or after a dose increase
- Constipation
- Nausea and vomiting
- Dry mouth
- Itching, flushing and sweating
- Confusion or vivid dreams in older people
- Slowed, shallow breathing — this is a medical emergency
Interactions to be aware of
- Alcohol, benzodiazepines and Z-drugs (sedative overdose risk)
- Gabapentin and pregabalin
- Other strong opioid painkillers
- Some antidepressants (including MAOIs)
- Antihistamines and other sedating medicines
UK legal position
Morphine is a Class A controlled drug, supplied as a Schedule 2 prescription-only medicine. NHS prescriptions for Schedule 2 and 3 controlled drugs are valid for 28 days from the date they are signed. It is never sold online and is only dispensed against a valid prescription from a UK prescriber.
Brand names you may see
Brand names are listed for identification only. We do not endorse or supply them.
This page provides general information only and does not constitute medical advice, a prescription or an offer to supply. Doses are decided by your prescriber. If you think you may need this medicine, speak to your GP, an NHS 111 clinician or a specialist pain service. In an emergency, call 999.