Pain management

New or changed pain can be a new problem — assess before treating.

Opioid-naive, older, frail or renally impaired: start low, go slow.

Act now

Site, onset, character, severity, what has been tried. Is it expected (post-op) or new?
Renal and liver function, allergies, current analgesia and opioid tolerance, sedation level, respiratory rate.
New pain red flags: compartment syndrome, limb ischaemia, cardiac, surgical abdomen.

Step up: paracetamol → add an NSAID if no contraindication → add a weak or strong opioid.
NSAID cautions: AKI or CKD, GI bleeding, heart failure, anticoagulants, aspirin-sensitive asthma.
Renal impairment: avoid codeine and use morphine with care; seek pharmacy or palliative advice for alternatives.
Prescribe a laxative with any regular opioid.

Pain not controlled, new pain suggesting a complication, or opioid toxicity (RR under 8, pinpoint pupils, drowsiness): senior; give naloxone if respiratory depression.

Paracetamol

1 g oral or IV every 4–6 hours, max 4 g in 24 hours (15 mg/kg if under 50 kg or at risk of hepatotoxicity).

Ibuprofen

400 mg oral 3 times daily with food.

Codeine phosphate

30–60 mg oral every 4 hours, max 240 mg/day.

Morphine sulfate oral solution

2.5–5 mg every 2–4 hours as needed (opioid-naive).

Naloxone

100–200 micrograms IV for opioid-induced respiratory depression, then 100 micrograms every 2 minutes as needed.

Senna

7.5–15 mg oral at night alongside regular opioids.

Check the BNF and your local formulary before prescribing.

Written to current guidance · sources checked 14 Nov 2026. We watch NICE for updates weekly.

Sources (2)

Reviewed by Aboodee Alhasso, MPharm MRCPharm IP on 14 Nov 2026

For healthcare professionals, as an aid to clinical judgement — not a substitute for it. Follow your local policy and ask a senior when in doubt.