ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Strong opioid analgesic Pregnancy: Use only if essential. Neonatal opioid withdrawal if prolonged use.

Morphine Sulphate (Burns Analgesia)

Brand names: Zomorph, MST Continus, Oramorph

Adult dose

Dose: IV PCA: 1 mg per bolus with 5 min lockout; IV infusion: 2–5 mg/hour; Oral: 5–10 mg every 4 hours
Route: IV (PCA or infusion), IM, oral, or subcutaneous
Frequency: Continuous or PCA in acute burns
Max: Titrated to pain; no absolute maximum in burns (dose by effect)
Acute major burns: IV PCA preferred for cooperative adults. Background infusion with PCA boluses for major burns or mechanically ventilated patients. Oral morphine for moderate burns when enteral route available. Procedure analgesia (dressing changes): IV bolus 2.5–5 mg with benzodiazepine or procedural sedation.

Paediatric dose

Dose: 0.1 mg/kg
Route: IV
Frequency: Every 2–4 hours or PCA
Max: 0.4 mg/kg/dose
Concentration: 1 mg/ml
0.1–0.2 mg/kg IV every 2–4 hours, or morphine PCA under specialist supervision. Paediatric burns: assess pain using age-appropriate pain scale (FACES, FLACC). Procedural sedation (dressing changes): IV ketamine + midazolam in many paediatric burns centres.

Dose adjustments

Renal

Reduce dose and frequency in renal impairment (active metabolite M6G accumulates).

Hepatic

Reduce dose in severe hepatic impairment.

Paediatric weight-based calculator

0.1–0.2 mg/kg IV every 2–4 hours, or morphine PCA under specialist supervision. Paediatric burns: assess pain using age-appropriate pain scale (FACES, FLACC). Procedural sedation (dressing changes): IV ketamine + midazolam in many paediatric burns centres.

Clinical pearls

  • Background infusion useful in major burns but increases tolerance and constipation
  • Dressing change analgesia: plan regular analgesic 30–60 min before dressing change
  • Burns pharmacokinetics changed: increased volume of distribution, protein binding changes — may need higher doses per kg than surgical patients
  • Ketamine increasingly preferred for procedural sedation in burns (bronchodilator, preserves airway reflexes)
  • Multimodal analgesia: combine with paracetamol, NSAIDs (if renal function preserved), gabapentin (neuropathic pain)

Contraindications

  • Respiratory depression without ventilatory support
  • Obstructive airway disease (relative)

Side effects

  • Respiratory depression
  • Nausea and vomiting
  • Constipation (long-term)
  • Sedation
  • Pruritus
  • Urinary retention

Interactions

  • CNS depressants (benzodiazepines, anaesthetic agents) — additive respiratory depression
  • MAOIs — contraindicated (serotonin syndrome/severe opioid toxicity)
  • Naloxone — reversal agent

Monitoring

  • Pain score (VAS/NRS)
  • Respiratory rate and SaO2
  • Sedation score
  • Bowel function

Reference: BNFc; BNF; British Burns Association Analgesia Guidelines; ANZBA Burns Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs
Pathways