When the patient is no longer able to swallow oral morphine, change to:
- Continuous morphine (or diamorphine) infusion via a syringe driver/pump (see conversion table).
- Prescribe a p.r.n. dose of subcutaneous morphine (or diamorphine) for breakthrough pain one sixth of the total 24-hour dose of morphine (or diamorphine). This can be given as frequently as necessary,up to 1 hourly when pain severe, and increased in proportion to any increase in 24-hour dose.
- If the patient is still in pain and the p.r.n. morphine (or diamorphine) has been found to be effective, the 24-hour dose of subcutaneous morphine (or diamorphine) may be increased by the sum of the PRN doses given in the previous 24 hours.
For patients requiring rapidly escalating doses of opioids or frequent use of p.r.n. doses, i.e. ≥2 a day, should prompt a review of pain management plan and consider contacting the Specialist Palliative Care Team for advice.
- If an opioid naïve patient does not currently have pain, prescribe subcutaneous morphine 2.5–5 mg (consider starting at 1.25mg for frail elderly) p.r.n. If after review at 24 hours two or more doses have been required, set up a syringe driver/pump containing morphine (or diamorphine).
If the patient is on an alternative strong opioid and needs to switch to a syringe driver/pump, see here for conversion doses or seek Specialist Palliative Care Team advice.