Morphine Slow-Release (Elderly Chronic Pain)

How it works

Morphine is a mu-opioid receptor agonist that produces analgesia through action on opioid receptors in the central nervous system.

Prescribing in practice

• Modified-release morphine carries a risk of respiratory depression and is not appropriate for acute pain titration; older patients are particularly susceptible to sedation and respiratory effects.
• Modified-release tablets must be swallowed whole and not crushed, as this can cause dangerous rapid release of the full dose.
• Doses should be reduced and titrated cautiously in renal impairment, common in the elderly, owing to accumulation of active metabolites.

Monitoring

Monitor analgesic efficacy, sedation, respiratory rate, confusion and constipation, with closer review during initiation and dose changes in older patients.

Counselling the patient

• Swallow the slow-release tablets or capsules whole and do not crush or chew them.
• A laxative is usually needed, as constipation is very common.
• Report excessive drowsiness or slow breathing urgently and avoid alcohol.

Evidence & guidelines

Modified-release morphine is a long-established treatment for chronic moderate to severe pain, with cautious use in the elderly per UK guidance.