Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Strong Opioid Analgesic

Morphine (IV/IM — Anaesthesia/ICU)

Brand names: Morphine Sulfate (generic), Sevredol (oral), Oramorph (oral)

Used in: Acute Coronary Syndrome & Chest Pain Burns

Morphine is a strong opioid for moderate-to-severe acute pain (including peri-operative and intensive care) and in palliative care; it is a controlled drug.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Morphine sulfate tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. ( 2.1 ) Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of morphine sulfate tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. ( 2.1 , 5 ) Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-10-10. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It is an agonist at opioid (mainly mu) receptors, reducing pain perception and transmission and producing dose-dependent respiratory depression.

Prescribing in practice

  • Constipation is almost universal — co-prescribe a laxative; nausea, sedation and itch are common.
  • Reduce the dose and lengthen intervals in renal impairment (active metabolites accumulate) and in older or frail patients; titrate to effect.
  • There is additive respiratory depression with other CNS depressants; naloxone reverses opioid effect in emergencies.

Monitoring

Monitor pain, sedation, respiratory rate and bowel habit; in acute or intravenous use observe closely for respiratory depression.

Counselling the patient

  • It commonly causes constipation — take the laxative provided.
  • It can cause drowsiness; do not drive while affected and avoid alcohol.
  • Take it only as prescribed; it can be habit-forming.

Evidence & guidelines

A strong opioid for severe acute pain and palliative care, used within opioid-stewardship principles and with attention to renal function.

Reference: RCoA Acute Pain Management Guidelines; Oxford Pain Group; MHRA on gabapentinoids + opioids; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs