Strong opioid
Hydromorphone
Hydromorphone hydrochloride
Hydromorphone is a strong opioid used for severe pain, particularly in palliative and cancer care. It is more potent than morphine and is usually chosen by a specialist when morphine is not working well or is not tolerated.
How this medicine is supplied
Prescription only in the UK. Dispensed by us only against a valid prescription from a UK prescriber.
How prescriptions workCall 999 for slow or shallow breathing, extreme drowsiness or unresponsiveness after taking an opioid.
What it is used for
- Severe cancer pain and pain in advanced illness
- Severe pain where morphine is ineffective or causes troublesome side effects
- Acute severe pain in hospital
How it works
Hydromorphone acts on opioid receptors in the central nervous system and is around five to seven times as potent as oral morphine. Because of that potency, it is nearly always started and adjusted by a specialist team.
Forms available in the UK
- Immediate-release capsules
- Modified-release capsules
- Oral solution
- Injection
Safety information you must know
- Modified-release capsules must be swallowed whole — never opened or crushed.
- Do not take with alcohol, benzodiazepines, sleeping tablets or gabapentinoids unless agreed with your prescriber.
- A laxative is usually prescribed alongside it.
- Avoid driving until you know how it affects you.
- Do not stop suddenly after regular use; the dose needs to be reduced gradually.
Common side effects
- Drowsiness
- Constipation
- Nausea and vomiting
- Dizziness
- Dry mouth
- Confusion in older or frail patients
- Slowed breathing — seek emergency help
Interactions to be aware of
- Alcohol and sedating medicines
- Benzodiazepines
- Gabapentin and pregabalin
- Other opioid analgesics
UK legal position
Hydromorphone is a Class A controlled drug and a Schedule 2 prescription-only medicine. Prescriptions are valid for 28 days. It is supplied only against a 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.