Morphine (Paediatric)

How it works

It is an agonist at mu-opioid receptors in the central nervous system, altering the perception of and response to pain.

Prescribing in practice

• The most important paediatric concern is dose-related respiratory depression, which is greater in neonates and infants owing to immature metabolism, so dosing must be cautious, weight-based and accompanied by appropriate monitoring.
• Active metabolites accumulate in renal impairment and effects are potentiated by other CNS depressants, increasing the risk of sedation and respiratory depression.
• Immediate-release and modified-release preparations are not interchangeable, and doses must be confirmed against a children's formulary with naloxone available.

Monitoring

Monitor respiratory rate, sedation score, oxygen saturation, pain scores and bowel function, with closer observation in the very young.

Counselling the patient

• The medicine can cause drowsiness and slowed breathing, so the child should be observed as advised.
• Constipation is common; a laxative may be needed and fluids encouraged.
• Use exactly as prescribed and keep securely away from other children.

Evidence & guidelines

Cautious, weight-based paediatric opioid dosing with monitoring for respiratory depression is standard practice reflected in NICE and specialist palliative-care guidance.