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Opioid Analgesic — Severe Ureteric Colic / Post-Operative Pain

Morphine

Brand names: Oramorph, Morphine Sulfate, MST Continus

Morphine is a strong opioid analgesic used in urology for severe acute pain such as renal/ureteric colic and post-operative pain, available by oral and parenteral routes.

Dosing — not shown for this use

The product information we hold does not support a dose for this page's specific use, route or population, so none is shown. Follow your local or national guideline, and confirm against the product SmPC.

The licensed dosing — for the medicine's licensed uses, which may differ from this page's — is on Morphine.

Clinical monograph

How it works

It is an agonist at mu-opioid receptors in the central nervous system, modulating ascending pain transmission and the perception of pain.

Prescribing in practice

  • Morphine causes dose-dependent respiratory depression and sedation, so titrate carefully, observe the patient, and have naloxone available, particularly with parenteral use or in the opioid-naive.
  • Reduce dose and extend intervals in renal impairment, as active metabolites accumulate and prolong effects — relevant given obstructive uropathy can impair renal function.
  • It is constipating and has dependence potential, so co-prescribe a laxative and review duration of use.

Monitoring

Monitor pain control, respiratory rate, sedation level and blood pressure, with bowel function over continued use.

Counselling the patient

  • It may cause drowsiness; do not drive or operate machinery if affected and avoid alcohol.
  • Constipation is common, so use the laxative provided; report severe drowsiness or slow breathing urgently.

Evidence & guidelines

Opioids including morphine are established for severe pain; in renal colic, NICE notes NSAIDs are first line with opioids used where NSAIDs are unsuitable or insufficient.

Reference: RCEM Clinical Standards for Emergency Analgesia; EAU Urolithiasis Guidelines 2024; 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.

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