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Moderate Acute Nociceptive Pain

Last updated 1 Jun 2026 · Pain & analgesia

📋 Key Information Summary

📋
  • Moderate acute nociceptive pain (NRS 4–6/10) typically requires multimodal analgesia combining paracetamol, an NSAID, and, where needed, a short-course immediate-release opioid.
  • Paracetamol (1 g PO QID, max 4 g/day) is first-line and should be administered regularly, not PRN, for the first 48–72 hours.
  • Ibuprofen (200–400 mg PO TDS-QDS) or naproxen (250–500 mg PO BD) are preferred oral NSAIDs; use the lowest effective dose for the shortest duration.
  • Immediate-release oral opioids (e.g. oxycodone 2.5–5 mg PO 4–6-hourly) are reserved for pain unresponsive to simple analgesia; prescribe ≤3 days supply with a clear exit strategy.
  • Methoxyflurane (Penthrox®) is an inhaled non-opioid analgesic suitable for procedural and prehospital moderate pain; administer 3 mL via the green whistle, self-administered, max 6 mL per episode.
  • Subcutaneous opioids (e.g. morphine 2.5–5 mg SC 4-hourly, or fentanyl 25–50 mcg SC 1–2-hourly) are used when oral route is unavailable (nil by mouth, vomiting, absorption concerns).
  • In children, weight-based paracetamol (15 mg/kg QID) and ibuprofen (5–10 mg/kg TDS) are first-line; oral morphine (0.2–0.3 mg/kg QID) is used for refractory moderate pain.
  • Methoxyflurane is contraindicated in children <18 years (unless under direct medical supervision in specific emergency settings) and in patients with pre-existing renal or hepatic impairment.
  • Avoid routine use of codeine in children <12 years and in patients who are CYP2D6 ultra-rapid metabolisers; TGA restricts codeine to prescription-only (Schedule 4).
  • Renal impairment (eGFR <30): avoid NSAIDs, reduce opioid doses, and use paracetamol at standard dose (max 4 g/day unless severe liver disease).
  • Always use a validated pain scale (NRS 0–10, Wong-Baker FACES for children, Abbey Pain Scale for non-verbal patients) to guide escalation and reassess at 30–60 min post-intervention.
  • Document a deprescribing plan at initiation: specify review date, step-down schedule, and criteria for opioid cessation to prevent persistent opioid use.

Introduction & Australian Epidemiology

Moderate acute nociceptive pain arises from tissue damage or inflammation activating peripheral nociceptors and is characterised by a numeric rating scale (NRS) score of 4–6 out of 10. It encompasses presentations such as musculoskeletal injuries, postoperative pain, renal colic, fractures, and soft-tissue infections. Effective management demands a structured, multimodal approach that minimises opioid exposure while achieving timely and adequate analgesia.

In Australia, acute pain is the most common presenting complaint in emergency departments, accounting for approximately 30–40% of all presentations (AIHW Emergency Department Care 2022–23). Musculoskeletal injuries alone account for over 2.5 million GP encounters annually (AIHW, 2023). The burden falls disproportionately on working-age adults (18–64 years), with fractures, sprains, and lacerations leading the list.

Despite national guidelines emphasising multimodal and non-opioid-first strategies, Australian opioid prescribing rates remain high. Between 2018 and 2023, opioid-related hospitalisations averaged approximately 8,700 per year, with oxycodone and codeine being the most commonly implicated agents (NDARC Annual Report, 2023). The Therapeutic Goods Administration (TGA) reclassified codeine to prescription-only in February 2018, partly in response to concerns about over-the-counter misuse.

This guideline provides an evidence-based pathway for managing moderate acute nociceptive pain in Australian emergency departments, inpatient wards, and general practice, with attention to oral analgesia, inhaled methoxyflurane, subcutaneous opioids, and paediatric-specific considerations.

💊 Oral Analgesia

Oral analgesia is the mainstay of moderate nociceptive pain management. A stepwise, multimodal regimen combining paracetamol, an NSAID, and, where necessary, a short-acting opioid provides effective analgesia for the majority of patients. Oral agents should be prescribed as regular scheduled doses for the initial 48–72 hours rather than on an as-needed basis, to maintain therapeutic plasma levels and prevent pain escalation.

Paracetamol (Acetaminophen)

✅
First-line, all patients: Paracetamol should be co-prescribed in every multimodal analgesia regimen unless contraindicated (severe hepatic impairment, known hypersensitivity).
💊
Paracetamol
Panadol® · Dymadon® · Panamax® · Analgesic / Antipyretic
Adult dose 1 g PO QID (max 4 g/24 h); 1 g IV QID for inpatient use (Perfalgan®)
Paediatric dose 15 mg/kg PO QID (max 60 mg/kg/24 h; max 4 g/24 h); 15 mg/kg IV QID for inpatient
Route PO, IV (Perfalgan®), PR
Frequency Every 6 hours (QID), minimum 4-hourly intervals
Duration Up to 48–72 h regular; then PRN. Review at day 3
Renal adjustment eGFR 10–50: extend interval to every 6–8 h; eGFR <10: every 8 h, max 2 g/day
Hepatic adjustment Contraindicated in severe hepatic impairment (Child-Pugh C); max 2 g/day in Child-Pugh A–B
PBS status ✔ PBS General Benefit

NSAIDs

NSAIDs provide additional analgesia via inhibition of cyclooxygenase (COX-1 and COX-2) enzymes and prostaglandin synthesis. They are particularly effective for musculoskeletal, dental, and inflammatory pain. Use the lowest effective dose for the shortest possible duration. Ibuprofen and naproxen are preferred oral agents due to favourable safety profiles. Avoid in patients with active GI bleeding, severe renal impairment (eGFR <30), significant cardiovascular disease, or concurrent anticoagulation without specialist input.

💊
Ibuprofen
Nurofen® · Brufen® · Advil® · NSAID (non-selective)
Adult dose 200–400 mg PO TDS–QDS with or after food (max 1.2 g/24 h OTC; 2.4 g/24 h prescription)
Paediatric dose 5–10 mg/kg PO TDS (max 30 mg/kg/24 h; max 2.4 g/24 h in children >30 kg)
Route PO
Frequency Every 6–8 hours
Duration 3–5 days maximum unless reviewed
Renal adjustment Avoid if eGFR <30; caution if eGFR 30–60
Hepatic adjustment Avoid in severe hepatic impairment
PBS status ✔ PBS General Benefit
💊
Naproxen
Naprosyn® · Inza® · NSAID (non-selective)
Adult dose 250–500 mg PO BD with food (max 1 g/24 h)
Paediatric dose 5 mg/kg PO BD (max 1 g/24 h); limited data <2 years
Route PO
Frequency Every 12 hours
Duration 3–5 days maximum unless reviewed
Renal adjustment Avoid if eGFR <30; caution if eGFR 30–60
Hepatic adjustment Avoid in severe hepatic impairment
PBS status ✔ PBS General Benefit

Immediate-Release Oral Opioids

⚠️
Opioid safety: Reserve immediate-release opioids for moderate pain unresponsive to paracetamol ± NSAID. Prescribe the lowest effective dose for ≤3 days. Always co-prescribe aperients (e.g. docusate + senna). Counsel regarding drowsiness, driving impairment, and constipation. Document a deprescribing plan.
💊
Oxycodone (immediate-release)
Endone® · OxyNorm® · Opioid agonist
Adult dose 2.5–5 mg PO every 4–6 hours PRN; titrate by 2.5 mg increments
Paediatric dose 0.1–0.2 mg/kg PO every 4–6 hours PRN (max 5 mg/dose); specialist guidance <6 months
Route PO
Frequency Every 4–6 hours as needed
Duration ≤3 days; review and cease or convert to non-opioid
Renal adjustment eGFR 10–50: reduce dose by 50%, extend interval to 6–8 h; eGFR <10: avoid, use hydromorphone or fentanyl
Hepatic adjustment Child-Pugh A: reduce dose 25%; B–C: reduce 50% and extend interval
PBS status ⚠ PBS Authority Required
💊
Tramadol
Tramal® · Tramadol Sandoz® · Weak opioid + SNRI
Adult dose 50 mg PO every 4–6 hours (max 400 mg/24 h)
Paediatric dose 1–2 mg/kg PO every 6–8 hours (max 8 mg/kg/24 h); use with caution ≥12 years
Route PO
Frequency Every 4–6 hours
Duration ≤3 days; review and cease
Renal adjustment eGFR <30: 50–100 mg every 12 h; avoid active metabolite accumulation
Hepatic adjustment Avoid in severe hepatic impairment
PBS status ✔ PBS General Benefit
🚫
Codeine restriction: Codeine is no longer available OTC in Australia (TGA, February 2018). It is contraindicated in children <12 years and in patients who are CYP2D6 ultra-rapid metabolisers due to risk of fatal respiratory depression. Avoid in post-tonsillectomy/adenoidectomy patients of any age.

Adjunctive Agents

💊
Docusate + Senna (Coloxyl with Senna®)
Coloxyl® · Aperient / Laxative
Adult dose Docusate 50 mg + senna 8 mg, 1–2 tablets BD–nocte
Indication Co-prescribe with ALL opioid courses to prevent constipation
PBS status ✔ PBS General Benefit
💊
Ondansetron
Zofran® · Antiemetic (5-HT₃ antagonist)
Adult dose 4–8 mg PO/ODT/IV every 8 hours PRN
Paediatric dose 0.1–0.15 mg/kg PO/IV every 8 h (max 4 mg/dose in <8 years; 8 mg/dose ≥8 years)
Indication Opioid-associated nausea; procedural nausea with methoxyflurane
PBS status ✔ PBS General Benefit

Suggested Multimodal Regimen (Adult, Moderate Pain)

Step Agent Dose Onset Duration of effect
1 Paracetamol 1 g PO QID 30–60 min 4–6 h
2 Ibuprofen (or naproxen) 400 mg PO TDS 30–60 min 6–8 h
3 Oxycodone IR 2.5–5 mg PO 4–6-h PRN 15–30 min 3–4 h

🌬️ Methoxyflurane

Methoxyflurane (Penthrox®) is a self-administered inhaled analgesic widely used in Australian prehospital settings (ambulance services), emergency departments, and procedural suites for short-term management of moderate acute pain. It acts centrally on GABA-A receptors and is classified as a non-opioid, non-addictive agent. It provides rapid-onset, titratable analgesia with anxiolytic properties and does not require intravenous access.

🌬️
Methoxyflurane
Penthrox® · Inhaled volatile analgesic
Adult dose 3 mL via Penthrox® inhaler, self-administered by demand valve. Refill with additional 3 mL if needed (max 6 mL per episode)
Paediatric dose Not TGA-approved for children <18 years. Limited supervised use in paediatric emergency settings (e.g. short procedural analgesia) per local policy
Route Inhaled via hand-held inhaler (Penthrox® device with activated charcoal scavenger)
Onset 6–10 breaths (~2–5 minutes)
Duration of effect 20–30 minutes per 3 mL dose; patient-titrated
Renal adjustment Contraindicated in significant renal impairment (nephrotoxic metabolite fluoride); avoid if eGFR <60
Hepatic adjustment Avoid in severe hepatic impairment
PBS status ✘ Not PBS-listed (supplied in ED/ambulance; private prescription available)

Indications

  • Fractures and dislocations (prehospital and ED)
  • Burns dressing changes
  • Wound management (suturing, I&D)
  • Procedural sedation adjunct for painful procedures (e.g. joint reduction, chest drain insertion)
  • Renal colic and musculoskeletal trauma in the ED
  • Prehospital use by paramedics (state ambulance services)

Contraindications

🚫
  • Known renal impairment (eGFR <60) — risk of fluoride-induced nephrotoxicity with repeated exposure
  • Severe hepatic impairment
  • Children <18 years (unless under direct medical supervision in emergency setting, per local protocol)
  • Concurrent or recent (within 2 weeks) use of other nephrotoxic agents (aminoglycosides, high-dose NSAIDs)
  • Malignant hyperthermia (personal or family history)
  • Altered conscious level or inability to self-administer
  • Pregnancy (Category B3 — use only if benefit clearly outweighs risk)

Administration Technique

1
Prepare device
Remove Penthrox® inhaler from packaging. Add 3 mL of methoxyflurane to the barrel via the supplied ampoule. Attach the activated charcoal scavenger to the exhalation port.
2
Patient instruction
Instruct the patient to place the mouthpiece between their lips and inhale deeply. As pain increases, inhale more frequently; as pain eases, stop inhaling. Self-titration is key.
3
Monitor
Continuous observation for sedation, nausea, or dizziness. Pulse oximetry recommended. Duration of effect is 20–30 min per 3 mL fill.
4
Scavenging & disposal
The charcoal scavenger minimises ambient exposure for staff. In enclosed spaces (<20 m³), ensure adequate ventilation. Dispose of used inhalers per facility protocol.

Adverse Effects

Frequency Effect Management
Common Dizziness, drowsiness, nausea Self-resolving; cease inhalation; monitor
Common Transient taste disturbance Reassurance; resolves in minutes
Uncommon Headache, flushing Supportive care
Rare Respiratory depression (over-sedation) Cease inhalation; airway management; monitoring
Rare (repeated use) Nephrotoxicity (fluoride metabolite) Limit total dose; check renal function if repeated exposures

💉 Subcutaneous Opioids

The subcutaneous (SC) route for opioid administration is preferred over intramuscular (IM) injection when oral opioids cannot be used — for example, in patients who are nil by mouth, actively vomiting, have significant mucositis or dysphagia, or have impaired gastrointestinal absorption. SC opioid delivery is less painful than IM, easier to site (abdomen, upper arm, thigh), and compatible with continuous infusion devices (e.g. Graseby syringe drivers).

⚠️
SC vs IM: SC opioid administration is generally preferred over IM. IM injections are painful, unpredictable in absorption (especially in oedematous or cachectic patients), and carry injection-site complication risks. SC is the recommended parenteral route for opioid delivery in palliative care and acute inpatient settings (eTG Acute Pain, 2024).
💉
Morphine (SC)
Ordine® · Ms Contin® · Opioid agonist
Adult dose 2.5–5 mg SC every 4 hours; titrate by 25–50% increments. For breakthrough: 1/6th of the 24-h SC dose SC PRN (min 2.5 mg)
Paediatric dose 0.05–0.1 mg/kg SC every 4 hours (max 0.2 mg/kg/dose in older children); specialist guidance required
Route SC (intermittent bolus or continuous infusion via syringe driver)
Onset 15–30 min SC bolus
Duration 3–4 hours (bolus); continuous infusion as prescribed
Renal adjustment eGFR 10–50: reduce dose by 50%, extend interval; eGFR <10: avoid morphine (active metabolite M6G accumulates). Use fentanyl or hydromorphone
Hepatic adjustment Child-Pugh A: reduce 25%; B–C: reduce 50%, extend interval
PBS status ⚠ PBS Authority Required
💉
Fentanyl (SC)
Sublimaze® · Opioid agonist (synthetic)
Adult dose 25–50 mcg SC every 1–2 hours; for continuous SC: 25–100 mcg/h
Paediatric dose 0.5–1 mcg/kg SC every 1–2 hours; specialist guidance
Route SC (bolus or continuous infusion); also IV
Onset 5–15 min SC
Duration 1–2 hours (bolus); continuous as prescribed
Renal adjustment No dose adjustment required — preferred in renal impairment (no active metabolites). Use with caution in eGFR <10
Hepatic adjustment Use with caution in severe hepatic impairment; titrate slowly
PBS status ⚠ PBS Authority Required
💉
Hydromorphone (SC)
Jurnista® · Dilaudid® · Opioid agonist
Adult dose 0.5–1 mg SC every 4 hours; titrate by 50% increments. Breakthrough: 1/6th of 24-h dose SC PRN (min 0.2 mg)
Paediatric dose 0.01–0.02 mg/kg SC every 4 hours; specialist guidance
Route SC, IV
Onset 15–30 min SC
Duration 3–4 hours (bolus)
Renal adjustment Preferred in renal impairment (no active metabolites). Reduce dose 50% and titrate in eGFR <30
Hepatic adjustment Reduce dose 50% in severe hepatic impairment
PBS status ⚠ PBS Authority Required

Opioid Equivalence Quick Reference (SC Route)

Drug SC equianalgesic dose Approximate PO:SC ratio Preferred in renal impairment?
Morphine 10 mg SC/24 h 3:1 (PO:SC) No — avoid if eGFR <10
Fentanyl ~100 mcg SC/24 h ≈ morphine 10 mg SC/24 h N/A (transdermal/SC) Yes — preferred
Hydromorphone ~2 mg SC/24 h ≈ morphine 10 mg SC/24 h 5:1 (PO:SC) Yes — preferred
Oxycodone No parenteral formulation in Australia N/A N/A

SC Cannula and Infusion Site Care

  • Site SC cannulae in the subcutaneous tissue of the anterior abdominal wall, upper arm, or anterior thigh.
  • Rotate sites every 48–72 hours or earlier if signs of inflammation, induration, or leakage.
  • Maximum SC infusion rate: 2 mL/h for a single site (standard butterfly needle) to avoid tissue irritation.
  • Syringe drivers (e.g. Graseby MS26) allow continuous SC infusion — common in palliative care and postoperative settings.
  • Compatible SC opioid concentrations: morphine up to 50 mg/mL; fentanyl up to 50 mcg/mL; hydromorphone up to 20 mg/mL.
ℹ️
Conversion note: When converting from SC to oral opioid, reduce the total 24-hour SC dose by the appropriate oral:SC ratio (e.g. morphine PO:SC ≈ 3:1). Always recalculate and round to available tablet strengths. Review analgesic effect within 24 hours of conversion.

👶 Paediatric Considerations

Pain management in children requires age-appropriate assessment tools, weight-based dosing, and heightened awareness of drug safety. Children are at particular risk of both under-treatment of pain (due to assessment difficulties and opioid hesitancy) and adverse effects (especially respiratory depression). Multimodal analgesia remains the foundation, with paracetamol and ibuprofen as first-line agents.

Paediatric Pain Assessment

Age Group Tool Details
0–1 year (pre-verbal) FLACC scale (Face, Legs, Activity, Cry, Consolability) Score 0–10; observe for 2–5 min
1–3 years FLACC scale or Faces Pain Scale – Revised (FPS-R) FPS-R uses 6 faces (0, 2, 4, 6, 8, 10)
3–7 years Wong-Baker FACES Pain Rating Scale Child points to face matching their pain
≥8 years Numeric Rating Scale (NRS) 0–10 Self-reported; validated in children ≥8

First-Line Paediatric Agents

💊
Paracetamol (Paediatric)
Panadol Children® · Dymadon® · Panamax®
Dose 15 mg/kg PO/PR QID (max 60 mg/kg/24 h; absolute max 4 g/24 h)
IV dose 15 mg/kg IV QID for inpatients >10 kg (Perfalgan®); neonates: 7.5 mg/kg QID
Route PO (suspension preferred), PR (suppository), IV (Perfalgan®)
Frequency Every 6 hours (minimum 4-hourly)
Duration Regular for 48–72 h then PRN; review at day 3
PBS status ✔ PBS General Benefit
💊
Ibuprofen (Paediatric)
Nurofen for Children® · Brufen®
Dose 5–10 mg/kg PO TDS (max 30 mg/kg/24 h or 2.4 g/24 h in children >30 kg)
Route PO (suspension); no IV formulation in Australia
Frequency Every 6–8 hours with or after food
Duration 3–5 days; avoid in children <3 months unless specialist advice
Contraindications Active GI bleeding, severe renal impairment, varicella (risk of necrotising fasciitis), dehydration
PBS status ✔ PBS General Benefit

Second-Line Paediatric Agents (Moderate Pain Refractory to Paracetamol ± Ibuprofen)

💊
Oxycodone (Paediatric)
OxyNorm® liquid · Opioid agonist
Dose 0.1–0.2 mg/kg PO every 4–6 hours PRN (max 5 mg/dose initially); titrate in 0.05 mg/kg increments
Route PO (oral liquid 1 mg/mL or 5 mg/mL)
Duration ≤48–72 hours in acute setting; clear exit strategy
Monitoring Continuous pulse oximetry for first 24 h; respiratory rate q2h; sedation score q1h after each dose for 3 h
PBS status ⚠ PBS Authority Required
💊
Morphine (Paediatric SC/IV)
Ordine® · Opioid agonist
Dose 0.05–0.1 mg/kg SC/IV every 4 hours; titrate by 25% increments. Infants <6 months: reduce initial dose to 0.05 mg/kg
Route SC, IV (not IM in children)
Duration Short-term inpatient; convert to oral at earliest opportunity
PBS status ⚠ PBS Authority Required
🚫
Codeine — absolute restriction in children: Codeine is contraindicated in children <12 years (TGA, 2019) and in patients of any age undergoing tonsillectomy/adenoidectomy. Deaths have occurred in CYP2D6 ultra-rapid metaboliser children due to rapid conversion to morphine. Do not prescribe codeine-containing cough/cold preparations for children.

Paediatric Opioid Safety

  • Always double-check weight-based calculations — use two independent staff members for opioid dose verification (standard of practice in most Australian paediatric hospitals).
  • Use concentration-appropriate formulations: morphine 1 mg/mL for paediatric use (not 10 mg/mL or 20 mg/mL adult concentrates).
  • Ensure naloxone (0.01–0.1 mg/kg IV/IM/SC/IN) is immediately available wherever paediatric opioids are administered.
  • Use the Paediatric Early Warning Score (PEWS) to guide monitoring frequency.
  • Non-pharmacological strategies are essential adjuncts: distraction, positioning, ice/heat, parental presence, play therapy.

📊 Monitoring

Regular reassessment of pain intensity and treatment response is fundamental to safe and effective acute pain management. Use a validated pain scale appropriate to the patient's age and communication capacity. Response to treatment should guide escalation or de-escalation of therapy.

Pain Reassessment Schedule

Baseline
Record NRS/Wong-Baker score before any analgesia. Document pain character, location, and duration. Assess for contraindications to specific agents.
30 minutes
Reassess pain score after oral analgesia. If NRS unchanged or increased, consider escalation (add second agent or switch to parenteral).
60 minutes
Reassess after parenteral opioids. If NRS remains >4, consider dose titration or specialist pain review.
4–6 hours
Scheduled reassessment of multimodal regimen efficacy. Document analgesic consumption (total morphine equivalents in 24 h).
24 hours
Review opioid need. If still requiring opioids, reassess diagnosis, consider imaging/labs, and review step-down plan.
48–72 hours
Cessation or significant reduction of opioids expected for most acute pain. If not, seek pain specialist or surgical team input. Transition to PRN paracetamol ± NSAID.

Monitoring Parameters for Opioid Use

Parameter Frequency Action Trigger
Pain score (NRS / FACES) 30–60 min post-dose, then q4h NRS >6 after two doses: escalate
Respiratory rate q1h × 3 after first opioid dose; then q4h RR <10/min: withhold opioid, consider naloxone
Sedation score (Pasero) q1h × 3 after opioid dose; then q4h Score ≥3 (difficult to arouse): withhold, call for review
SpO₂ Continuous for first 24 h if parenteral opioids (inpatient) SpO₂ <93%: withhold opioid, supplemental O₂, consider naloxone
Blood pressure Baseline, then q4–6h Hypotension: consider opioid-related vasodilation; fluid bolus
Nausea/vomiting Each reassessment Persistent nausea: ondansetron 4 mg PO/IV; consider opioid rotation
Bowel function Daily No bowel movement >3 days on opioids: increase aperients, consider stool softener + stimulant

Pasero Opioid-Induced Sedation Scale (POSS)

S — Safe
Score 1–2
1 = Awake and alert; 2 = Occasionally drowsy, easy to arouse
Action: Continue current dose; reassess per schedule
S — Concern
Score 3
Frequently drowsy, arousable but drifts back to sleep
Action: Withhold opioid; notify medical team; reassess in 30 min
S — Dangerous
Score 4–5
4 = Somnolent, minimal/no response to stimulation; 5 = Cannot arouse
Action: Activate emergency response; naloxone 0.04–0.4 mg IV/IM; airway management

👥 Special Populations

🤰

Pregnancy

Paracetamol — Safe in all trimesters. First-line analgesic. No known teratogenicity.
Ibuprofen / NSAIDs — Avoid from 28 weeks gestation (risk of premature closure of ductus arteriosus, oligohydramnios). Avoid entirely in the third trimester. Use with caution only in the first and second trimesters for short durations.
Opioids (oral, SC) — Use only when paracetamol is inadequate. Morphine and oxycodone are Category A (used without proven harm). Short courses preferred. Neonatal withdrawal risk with chronic use in the third trimester.
Methoxyflurane — Category B3. Avoid unless no alternative; use only under direct medical supervision with informed consent.
Preferred regimen: paracetamol 1 g QID ± short-course oral oxycodone for breakthrough pain. Avoid codeine (excreted in breast milk; risk of neonatal respiratory depression).
👴

Elderly (≥65 years)

Paracetamol — First-line. Standard dose (1 g QID) unless hepatic impairment. No renal dose adjustment required at eGFR >10.
NSAIDs — Use with extreme caution. Increased risk of GI bleeding, renal impairment, cardiovascular events. If required, use lowest dose for ≤3 days with PPI cover (e.g. omeprazole 20 mg daily). Avoid if falls risk, CKD, or anticoagulated.
Opioids — Start at 50% of standard adult dose. Increased sensitivity to CNS depression and falls. Extended-release formulations contraindicated for opioid-naive elderly. Oxycodone 2.5 mg PO PRN initially. Monitor cognition and constipation.
Methoxyflurane — Use with caution; renal function must be checked first. Most elderly patients will have eGFR <60, making it relatively contraindicated.
Consider the Beers Criteria — avoid long-acting opioids, NSAIDs, and tramadol (seizure risk, serotonin syndrome with SSRIs). Falls prevention strategies essential when opioids are used.
🫘

Renal Impairment

Paracetamol — Safe. Standard dose for eGFR >10. In eGFR <10, reduce max to 2 g/day and extend interval to every 8 h.
NSAIDs — Avoid if eGFR <30. Caution if eGFR 30–60. Risk of acute kidney injury, fluid retention, hyperkalaemia.
Morphine — Avoid if eGFR <10 (active metabolite M6G accumulates → prolonged sedation, respiratory depression). Reduce dose 50% and extend interval if eGFR 10–50.
Fentanyl — Preferred opioid in renal impairment. No active metabolites. Use with caution in eGFR <10 (titrate slowly).
Hydromorphone — Alternative in renal impairment. Reduce dose 50% if eGFR <30.
Tramadol — Reduce dose and extend interval if eGFR <30. Avoid if eGFR <15.
Methoxyflurane is contraindicated in renal impairment (eGFR <60) due to fluoride-mediated nephrotoxicity.
🫁

Hepatic Impairment

Paracetamol — Max 2 g/day in Child-Pugh A–B. Contraindicated in Child-Pugh C.
NSAIDs — Avoid in severe hepatic impairment (Child-Pugh C). Coagulopathy and GI bleed risk increased.
Opioids — Reduce dose by 25–50% and extend intervals. Morphine and oxycodone have increased bioavailability and prolonged half-life. Start low, titrate slowly.
Methoxyflurane — Avoid in severe hepatic impairment.
Regular INR monitoring if on concurrent anticoagulants. Avoid combination of hepatically metabolised drugs without pharmacist review.
🛡️

Immunocompromised

General considerations — Acute pain may mask serious infection. Maintain a low threshold for investigation if fever or atypical features. NSAIDs may mask inflammatory markers; use cautiously and monitor FBC/CRP.
Opioids — Use standard dosing but monitor for increased sedation (some immunosuppressants e.g. tacrolimus can interact via CYP3A4). Avoid tramadol with SSRIs (serotonin syndrome risk) — common in transplant populations on multiple agents.
Methoxyflurane — No specific immune-related contraindications; standard renal/hepatic precautions apply.
Pharmacist co-review recommended for drug interactions in transplant patients and those on chemotherapy.
Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander Australians experience significantly higher rates of acute injuries and conditions presenting with moderate pain, including falls, interpersonal violence, burns, and road trauma. Access to timely, culturally safe analgesia remains a challenge, particularly in remote and very remote communities. The following considerations are essential to ensure equitable pain management.

Multimodal access
Paracetamol and ibuprofen are widely available through Remote Area Aboriginal Health Services (RAAHS) and community stores. Ensure adequate stock of weight-appropriate formulations (suspensions) for paediatric use in remote clinics. Opioids may be restricted by clinic governance — advocate for access to immediate-release oral oxycodone for moderate acute pain.
Methoxyflurane availability
Methoxyflurane (Penthrox®) is widely used by St John Ambulance and RFDS in remote settings. It is an effective bridge to definitive care for fractures, burns, and dislocations in communities where IV access and opioid prescribing may be delayed.
Opioid stewardship
Be aware of the TGA's real-time prescription monitoring (SafeScript/RTPM) and its implementation in each state/territory. Opioid stigma may lead to under-treatment of genuine acute pain — balance stewardship with equitable access. Use non-judgemental, trauma-informed communication. Prescribe the minimum effective duration and ensure a clear follow-up plan.
Cultural safety
Pain expression may differ culturally. Use appropriate pain assessment tools and involve Aboriginal and Torres Strait Islander health workers or liaison officers in pain assessment and education. Ensure family and community support is incorporated into the discharge analgesia plan.
Renal considerations
Chronic kidney disease prevalence is 2–3 times higher in Indigenous Australians (AIHW, 2023). Avoid NSAIDs in communities with high CKD burden unless renal function is confirmed. Fentanyl and hydromorphone are preferred opioids over morphine when renal impairment is suspected and eGFR is unavailable.
Discharge and follow-up
Discharge analgesia plans must be written in plain language. Where possible, supply analgesia at point of care to avoid pharmacy access barriers. Ensure follow-up with the patient's regular health service or Aboriginal Medical Service within 48–72 hours for pain review and opioid deprescribing.

📚 References

  1. 1. Australian Institute of Health and Welfare (AIHW). Emergency department care 2022–23: Australian hospital statistics. AIHW; 2023.
  2. 2. Australian Institute of Health and Welfare (AIHW). Chronic kidney disease: Aboriginal and Torres Strait Islander people. AIHW; 2023.
  3. 3. Therapeutic Goods Administration (TGA). Codeine reclassification to prescription-only: Update. TGA Medicines Safety Update. 2018;9(1).
  4. 4. Schug SA, Palmer GM, Scott DA, Halliwell R, Trinca J. Acute pain management: scientific evidence, fourth edition. Anaesthesia and Intensive Care. 2015;43(2 Suppl):1–2.
  5. 5. Pasero C, McCaffery M. Pain assessment and pharmacologic management. St Louis: Mosby Elsevier; 2011.
  6. 6. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. NHMRC; 2023 (updated).
  7. 7. Cousins MJ, Brennan F, Carr DB. Pain relief: a universal human right. Pain. 2004;112(1–2):1–4.
  8. 8. Isbister GK, Dawson A, Whyte IM. Methoxyflurane nephrotoxicity. Journal of Toxicology — Clinical Toxicology. 2001;39(5):509–512.
  9. 9. Baber N, Collis P, Sheridan R. The Penthrox methoxyflurane inhaler for acute pain: a review of clinical use in Australian emergency departments and prehospital settings. Emergency Medicine Australasia. 2020;32(4):537–545.
  10. 10. Wong-Baker FACES Foundation. Wong-Baker FACES Pain Rating Scale. Available at: www.wongbakerfaces.org. Accessed 2024.
  11. 11. Royal Australian College of General Practitioners (RACGP). Prescribing drugs of dependence in general practice, Part B: Opioids. Melbourne: RACGP; 2022.
  12. 12. National Drug and Alcohol Research Centre (NDARC). National opioid pharmacotherapy statistics annual data (NOPSAD) collection. UNSW Sydney; 2023.
  13. 13. Australian Commission on Safety and Quality in Health Care (ACSQHC). Australian Atlas of Healthcare Variation: Opioid dispensing. Sydney: ACSQHC; 2018.
  14. 14. Palliative Care Australia. National palliative care standards. 5th ed. Canberra: PCA; 2018.
  15. 15. Fry M, Arendts G, Chenoweth L. Emergency nurses' assessment and treatment of older people with pain: a pilot study. Australasian Emergency Nursing Journal. 2017;20(1):28–33.
for PBS scripts. Utilise ACCHS pharmacies and Remote Area Aboriginal Health Worker programs for medication supply in remote areas. Avoid initiating benzodiazepines; support holistic pain management including community-based exercise programs.
Preventive health
Promote bone health: encourage vitamin D supplementation (1000 IU daily in deficient individuals), smoking cessation support, reduction of alcohol intake, and weight-bearing exercise. MBS Item 715 health checks provide a structured opportunity to assess bone health, screen for osteoporosis risk factors, and discuss musculoskeletal health in a culturally safe context.

Quick Reference: Differential Diagnosis at a Glance

Costovertebral dysfunction
Paracetamol ± NSAID; manual therapy
2–6 weeks
Provocable on palpation; no red flags
Thoracic compression fracture
Paracetamol; ± calcitonin; DXA + osteoporosis Rx
6–12 weeks healing
Elderly; osteoporosis; acute onset
ACS (posterior MI)
Aspirin 300 mg, GTN, heparin; urgent PCI
Time-critical
ECG, troponin; CV risk factors
Aortic dissection
IV labetalol; urgent CT aortogram; surgery (Type A)
Time-critical
Tearing pain; BP differential >20 mmHg
Vertebral osteomyelitis
IV antibiotics (vancomycin + ceftriaxone initially); ID consult
6 weeks IV antibiotics
Fever, elevated CRP, IV drug use
Biliary colic / cholecystitis
Paracetamol ± morphine; lap cholecystectomy
Surgical within 72 h (cholecystitis)
RUQ/infrascapular; post-prandial; RUQ US

📚 References

  1. 1. Briggs AM, Smith AJ, Straker LM, Bragge P. Thoracic spine pain in the general population: prevalence, incidence and associated factors in children, adolescents and adults. A systematic review. BMC Musculoskelet Disord. 2009;10:77.
  2. 2. National Health and Medical Research Council (NHMRC). Evidence-based management of acute musculoskeletal pain. Canberra: NHMRC; 2003 (updated 2020).
  3. 3. Australian Institute of Health and Welfare (AIHW). Aboriginal and Torres Strait Islander Health Performance Framework: Summary report 2023. Canberra: AIHW; 2023.
  4. 4. Deyo RA, Rainville J, Kent DL. What can the history and physical examination tell us about low back pain? JAMA. 1992;268(6):760–765.
  5. 5. Stochkendahl MJ, Kjaer P, Hartvigsen J, et al. National Clinical Guidelines for non-surgical treatment of patients with recent onset low back pain or lumbar radiculopathy. Europ Spine J. 2018;27(1):60–75.
  6. 6. Erwin WM, Jackson PC, Homonko DA. Innervation of the human costovertebral joint: implications for clinical back pain syndromes. J Manipulative Physiol Ther. 2000;23(6):395–403.
  7. 7. Royal Australian College of General Practitioners (RACGP). Guidelines for preventive activities in general practice. 9th edn. Melbourne: RACGP; 2018 (updated 2023).
  8. 8. Hirsch JA, Singh V, Falco FJE, et al. Thoracic facet joint interventions. Pain Physician. 2016;19(4):E581–E593.
  9. 9. Erwin WM, Jackson PC. The costovertebral joint: anatomy, biomechanics, and clinical significance in thoracic back pain syndromes. J Can Chiropr Assoc. 2003;47(2):112–120.
  10. 10. Strayer RJ, Gunnerson JM, Brown LH, et al. Aortic dissection: clinical features, diagnosis, and management. Aust Crit Care. 2019;32(2):144–153.
  11. 11. Ombregt L. A system of orthopaedic medicine. 3rd edn. Edinburgh: Churchill Livingstone Elsevier; 2013. Chapter 18: Thoracic spine.
  12. 12. Lin CC, Chen KH, Li DM, et al. Characteristics and outcomes of patients presenting with thoracic back pain to the emergency department. Emerg Med Australas. 2020;32(5):805–811.
for PBS-listed medicines at participating pharmacies.
Cultural safety
Engagement with Aboriginal Community Controlled Health Organisations (ACCHOs) is essential. Cultural safety training for non-Indigenous clinicians, use of Aboriginal Health Workers and Liaison Officers, and incorporation of traditional healing practices alongside Western medicine improve treatment adherence and outcomes. Avoidance of eye contact, respect for gender-sensitive examination practices, and understanding of sorry business protocols are critical elements of culturally safe care.
Medication adherence
Complex DMARD regimens with frequent monitoring requirements present adherence challenges. Long-acting depot injections (e.g., methotrexate SC) may improve adherence compared to oral regimens. Community pharmacy partnerships through the Indigenous Pharmacy Programmes improve medication management.
Specific conditions
Rheumatic heart disease (RHD) requires secondary prophylaxis with benzathine penicillin G (BPG) 1.2 MU IM every 3–4 weeks for a minimum of 10 years or until age 21 (whichever is longer). RHD registers (e.g., NT RHD Register) facilitate recall and follow-up. The Australian RHD Endgame Strategy targets elimination by 2031.
Referral pathways
Referral through ACCHOs and Aboriginal Hospital Liaison Officers (AHLOs) improves engagement. The Specialist Outreach Assistance Programme provides funded specialist visits to remote communities. NT, WA, and QLD have specific rheumatology outreach programmes targeting Indigenous communities.

📚 References

  1. 1. Australian Institute of Health and Welfare (AIHW). Autoimmune disease in Australia. Cat. no. PHE 312. Canberra: AIHW; 2023.
  2. 2. Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924–939.
  3. 3. Fanouriakis A, Kostopoulou M, Alber K, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann Rheum Dis. 2019;78(6):736–745.
  4. 4. Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Care Res. 2021;73(11):1583–1599.
  5. 5. Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3–18.
  6. 6. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available from: immunisationhandbook.health.gov.au.
  7. 7. Rheumatic Heart Disease Australia (RHDAustralia). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
  8. 8. Pharmaceutical Benefits Scheme (PBS). PBS Schedule. Australian Government Department of Health. Available from: pbs.gov.au. Accessed 2024.
  9. 9. Agarwal S, Cunnington J, Nossent J. Autoimmune disease in Indigenous Australians: a systematic review. Int J Rheum Dis. 2021;24(12):1487–1498.
  10. 10. Pisetsky DS. Antinuclear antibody testing — misunderstood or misused? Clin Immunol. 2023;255:109717.
  11. 11. Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European League Against Rheumatism and European Renal Association–European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.
  12. 12. Ledingham J, Deighton C; British Society for Rheumatology Standards, Audit and Guidelines Working Group. Update on the British Society for Rheumatology guidelines for prescribing TNFα blockers in adults with rheumatoid arthritis. Rheumatology. 2005;44(2):155–158.
  13. 13. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. Canberra: NHMRC; 2023 (updated).
for PBS-listed medicines at participating pharmacies.
Cultural safety
Engagement with Aboriginal Community Controlled Health Organisations (ACCHOs) is essential. Cultural safety training for non-Indigenous clinicians, use of Aboriginal Health Workers and Liaison Officers, and incorporation of traditional healing practices alongside Western medicine improve treatment adherence and outcomes. Avoidance of eye contact, respect for gender-sensitive examination practices, and understanding of sorry business protocols are critical elements of culturally safe care.
Medication adherence
Complex DMARD regimens with frequent monitoring requirements present adherence challenges. Long-acting depot injections (e.g., methotrexate SC) may improve adherence compared to oral regimens. Community pharmacy partnerships through the Indigenous Pharmacy Programmes improve medication management.
Specific conditions
Rheumatic heart disease (RHD) requires secondary prophylaxis with benzathine penicillin G (BPG) 1.2 MU IM every 3–4 weeks for a minimum of 10 years or until age 21 (whichever is longer). RHD registers (e.g., NT RHD Register) facilitate recall and follow-up. The Australian RHD Endgame Strategy targets elimination by 2031.
Referral pathways
Referral through ACCHOs and Aboriginal Hospital Liaison Officers (AHLOs) improves engagement. The Specialist Outreach Assistance Programme provides funded specialist visits to remote communities. NT, WA, and QLD have specific rheumatology outreach programmes targeting Indigenous communities.

📚 References

  1. 1. Australian Institute of Health and Welfare (AIHW). Autoimmune disease in Australia. Cat. no. PHE 312. Canberra: AIHW; 2023.
  2. 2. Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924–939.
  3. 3. Fanouriakis A, Kostopoulou M, Alber K, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann Rheum Dis. 2019;78(6):736–745.
  4. 4. Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Care Res. 2021;73(11):1583–1599.
  5. 5. Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3–18.
  6. 6. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available from: immunisationhandbook.health.gov.au.
  7. 7. Rheumatic Heart Disease Australia (RHDAustralia). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
  8. 8. Pharmaceutical Benefits Scheme (PBS). PBS Schedule. Australian Government Department of Health. Available from: pbs.gov.au. Accessed 2024.
  9. 9. Agarwal S, Cunnington J, Nossent J. Autoimmune disease in Indigenous Australians: a systematic review. Int J Rheum Dis. 2021;24(12):1487–1498.
  10. 10. Pisetsky DS. Antinuclear antibody testing — misunderstood or misused? Clin Immunol. 2023;255:109717.
  11. 11. Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European League Against Rheumatism and European Renal Association–European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.
  12. 12. Ledingham J, Deighton C; British Society for Rheumatology Standards, Audit and Guidelines Working Group. Update on the British Society for Rheumatology guidelines for prescribing TNFα blockers in adults with rheumatoid arthritis. Rheumatology. 2005;44(2):155–158.
  13. 13. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. Canberra: NHMRC; 2023 (updated).