01Purpose and principlesWhat the treatment does and how it fits into care.
Pain prescribing begins with an account of what the pain represents and what improvement would enable the person to do. Acute nociceptive pain may follow tissue injury or inflammation; neuropathic pain arises from a lesion or disease of the somatosensory system; persistent pain may involve several mechanisms. Chronic primary pain is a specific clinical category and should not be treated as merely acute pain lasting longer. The same reported intensity can therefore lead to different treatments. A medicine is useful when it produces worthwhile relief or functional gain with acceptable harm, rather than simply changing a numerical score.
Clinical assessment and analgesia proceed together. Treating pain should not wait for every investigation, but apparent relief should not end diagnostic reasoning when warning features persist. Prescribing also includes practical support, such as protecting an injury, graded activity, sleep support or rehabilitation appropriate to the condition. Opioid potency does not measure the quality of the pain plan. When a drug fails, examine the diagnosis, actual use, duration of trial and adverse effects before moving to a stronger medicine. Continuing an ineffective treatment can create dependence and treatment burden without improving the underlying problem.
Key points
- Identify acute tissue injury, neuropathic pain, chronic primary pain or a mixture before choosing a drug strategy.
- Assess the cause and serious warning features while relieving pain; an analgesic response does not exclude dangerous pathology.
- Paracetamol in a suitable adult can be given orally 500 mg to 1 g every 4–6 hours, maximum four doses and 4 g in 24 hours, with individual reduction for risk factors.
- Use NSAIDs at the lowest effective dose for the shortest necessary period after renal, gastrointestinal, cardiovascular and pregnancy assessment.
- For neuropathic pain, choose and trial an appropriate agent with planned titration and functional review rather than repeatedly escalating simple analgesics.
- When opioids are justified, agree duration, review and stopping before starting, and assess sedation as well as pain relief.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
A close relationship to tissue injury, movement or inflammation suggests that treating the cause and using short-term analgesia may help. Establish whether the pain trajectory is expected. Increasing pain after initial improvement, pain out of proportion to findings or associated physiological deterioration warrants reassessment for complications rather than automatic repeat medication.
Burning, electric-shock sensations, allodynia or altered sensation in a neuroanatomically plausible pattern can suggest neuropathic pain. Descriptive words alone are insufficient: examine and seek a relevant lesion or disease. The treatment strategy differs from uncomplicated inflammatory pain, and the patient needs to understand the time required to assess benefit.
Consider this when pain or its impact is not adequately accounted for by an underlying condition, while continuing to assess changes in presentation. NICE NG193 supports physical and psychological approaches and selected antidepressants; it advises against initiating several familiar analgesic classes for this indication. The recommendation should not be applied indiscriminately to all chronic secondary pain.
Drowsiness, slowed breathing, falls, black stools, reduced urine output or new confusion may reflect treatment toxicity. Ask about combination cold remedies, purchased NSAIDs, sedatives and alcohol. Pain improvement accompanied by unsafe sedation is a harmful outcome, and a medicine can contribute even when it has been taken at the prescribed dose.
03Assessment before treatmentTests and checks that guide safe selection.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Pain history and functional baselineFirst step - Why
- Determine mechanism, severity and the outcome treatment should improve.
- Interpretation and limitations
- Ask about location, onset, character, aggravating factors, sleep and daily activity. Record a concrete task such as walking to the bathroom or returning to a chosen activity. Reassess the same task after treatment so a tolerable but ineffective drug is not continued solely because a prescription exists.
- 02
Focused examination and red-flag assessment - Why
- Identify the cause and conditions requiring urgent action.
- Interpretation and limitations
- Examine the relevant system and assess neurological, vascular, infectious or traumatic concerns according to the presentation. The required investigation depends on the suspected pathology. Routine imaging for every persistent pain complaint may produce incidental findings that do not explain the person’s symptoms.
- 03
Medicine and comorbidity review - Why
- Choose a regimen compatible with the patient’s risks and current exposure.
- Interpretation and limitations
- Check all analgesic ingredients, kidney function, liver risk, ulcer history, cardiovascular disease, pregnancy possibility and other sedating medicines. Ask what was actually taken over the last day, not just what is on repeat. This is particularly important before giving additional paracetamol or an opioid-containing combination.
- 04
Benefit and toxicity reassessment - Why
- Distinguish inadequate effect from inadequate delivery or emerging harm.
- Interpretation and limitations
- Review timing of doses, adherence, absorption and the expected onset of benefit. Check alertness and respiratory effort with opioids and appropriate renal or gastrointestinal surveillance with NSAIDs. Neuropathic agents need an adequate, tolerated trial, but severe adverse effects require action before a scheduled review.
04Treatment approachPreparation, options, escalation and aftercare.
01Worked caseChoose an interpretable neuropathic-pain trialFirst stepA 56-year-old has painful diabetic neuropathy with burning feet, reduced distal sensation and disrupted sleep. There is no acute foot lesion, significant cardiac disease, urinary retention, glaucoma concern or interacting antidepressant; kidney function is stable.+
- 1Confirm the neuropathic pattern and assess the feet for a separate cause of pain, ulceration or infection. Agree that better sleep and ability to walk to the local shop are the initial outcomes; do not promise complete pain abolition.
- 2Discuss NICE’s initial options for neuropathic pain and select according to comorbidity, likely adverse effects and preference. If amitriptyline is chosen, use a low oral evening starting dose and a planned titration, as detailed in the medicine entry.
- 3Explain that sedation can occur before useful analgesia and that increasing the dose too quickly may impair daytime function. Give advice about driving or machinery if drowsy and ask the person to report troublesome anticholinergic or cardiac symptoms.
- 4Review tolerability during titration and assess benefit after an adequate period at a tolerated regimen. A short ineffective exposure at a very low dose does not establish class failure, but persistent impairment without worthwhile gain argues against indefinite continuation.
- 5Verify progress against sleep and walking goals. If benefit is insufficient or adverse effects dominate, plan a suitable switch or supervised withdrawal and reassess the diagnosis. Document the outcome so later clinicians do not repeat an unsuccessful trial without understanding its limitations.
02Acute pain approachProvide relief with an early stopping planAn adult has a defined acute painful condition without an immediate threat requiring another emergency pathway.+
- 1Treat the cause and select analgesia appropriate to severity and mechanism. Use oral treatment when suitable and check previous doses before adding another product. Consider non-drug measures and explain what clinical change would require reassessment.
- 2For an NSAID, assess renal, gastrointestinal and cardiovascular risks, relevant interactions and pregnancy. Avoid combining oral NSAIDs. Consider whether gastroprotection is indicated, while recognising that it does not remove kidney or cardiovascular risk.
- 3If an opioid is necessary for severe acute pain, use an individualised immediate-release plan with appropriate observation, a limited supply and early review. Account for opioid tolerance, organ impairment and other sedatives; a fixed dose cannot safely cover every patient in these categories.
- 4Reassess pain, function and alertness, then reduce treatment as the condition improves. Avoid automatically converting a short acute prescription into a repeat; persistent pain needs its own diagnostic and benefit–harm review.
03Persistent pain reviewReconsider escalation when benefit is limitedEscalationA person has continuing pain despite several medicines, with little functional improvement and increasing adverse effects.+
- 1Reassess the pain category and any new warning features. Determine whether an underlying condition needs treatment, whether the pattern is neuropathic and whether chronic primary pain is present. Different categories can coexist and need a coordinated plan.
- 2Review previous trials with the patient: dose, duration, adherence, benefit and harm. Identify duplicate mechanisms or combinations causing sedation. An apparent need for higher doses may reflect tolerance, a new cause or an ineffective approach.
- 3For chronic primary pain, follow the specific NICE strategy rather than initiating paracetamol, NSAIDs, opioids or gabapentinoids as routine treatment. Discuss appropriate activity and psychological approaches, and consider a suitable antidepressant after explaining its intended pain-related benefit.
- 4Agree supported reduction of medicines with little value, taking dependence and withdrawal into account. Coordinate follow-up and specialist input where symptoms remain disabling, the diagnosis is uncertain or a complex opioid regimen requires review.
05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.
Paracetamol for short-term adult pain
500 mg to 1 g orally every 4–6 hours when required, maximum four doses and 4 g in 24 hours; use a short agreed course and reassess if pain persists.Include every paracetamol-containing product in the total. Low body weight, malnutrition, dehydration and hepatic or renal disease require an individual dose-limit assessment.
Ibuprofen for suitable acute inflammatory pain
200–400 mg orally up to three times daily when required, at least 4 hours between doses and maximum 1,200 mg in 24 hours for this selected short-term regimen; seek review if worsening or required beyond 10 days.Avoid significant renal disease, active or recurrent ulcer/bleeding, severe heart failure or previous NSAID hypersensitivity. Avoid routine use in pregnancy, particularly from 20 weeks; it is contraindicated in the third trimester. Check anticoagulants and other NSAIDs.
Amitriptyline for adult neuropathic pain
Start 10–25 mg orally in the evening; increase by 10–25 mg every 3–7 days as tolerated. The cited SmPC recommends 25–75 mg daily; assess analgesic response over 2–4 weeks and review continuation.Start at the lower end when vulnerable. Avoid recent myocardial infarction, heart block, rhythm disorders and relevant MAOI combinations; assess anticholinergic burden, falls, overdose risk and pregnancy before use. Withdraw gradually when stopping.
Naloxone for postoperative opioid respiratory depression
Adult postoperative regimen: 100–200 micrograms intravenously initially, with further 100-microgram increments separated by a full 2 minutes, titrating to respiratory recovery under close monitoring.Rapid excessive reversal can precipitate pain or withdrawal. Respiratory depression may recur as naloxone wears off; repeat treatment or an infusion may require expert management. Acute overdose uses a different dosing strategy.
06Complications, monitoring and follow-upAdverse effects, response and longer-term review.
- Continue an analgesic only when the patient describes a worthwhile benefit or a clearly justified preventive role. Track function and sleep alongside intensity so treatment does not drift toward escalating doses without measurable value.
- With opioids, monitor sedation and ventilation and reassess constipation, nausea, falls and cognitive effects. Renal deterioration or a new sedative can change risk without any opioid dose increase.
- With NSAIDs, review current hydration and kidney risk, gastrointestinal symptoms, blood pressure and continuing need. A protective stomach medicine does not make prolonged NSAID treatment universally safe.
- When stopping long-term treatment, provide a medicine-specific withdrawal plan and follow-up. Explain that physical dependence can develop with therapeutic use and needs support; it should not be treated as a moral failing.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Intensity is not mechanism
A severe score does not establish that an opioid is the best treatment. Mechanism, duration, cause and functional impact are needed to select a meaningful intervention. Asking what the person cannot do often adds more useful information than repeatedly asking for a number.
Benefit can be delayed
Neuropathic-pain treatment may need titration and time before a fair assessment. Early adverse effects may appear before benefit, so explain the sequence and arrange review. Do not use delayed onset as a reason to persist through dangerous toxicity.
Combination labels conceal ingredients
Products marketed for pain, colds or sleep may contain overlapping analgesics or sedatives. Ask the patient to bring packets or photographs. Ingredient-level reconciliation can prevent toxicity even when no individual product is taken above its own stated dose.
An opioid exit plan
Before starting an opioid, discuss the anticipated duration and how treatment will stop as recovery occurs. If benefit remains limited, review the underlying condition and agree a supported reduction rather than allowing dose escalation to become the only available response.
08Common pitfallsFrequent interpretation and management errors.
- 01
Escalating analgesia for worsening pain without reassessment may delay diagnosis of an acute complication that needs definitive treatment.
- 02
Adding an oral NSAID to another oral NSAID increases harm without creating a rational multimodal plan.
- 03
Applying chronic-primary-pain guidance to every chronic pain syndrome overlooks distinct recommendations for neuropathic or other secondary pain.
- 04
Assuming familiar over-the-counter products cannot cause serious toxicity misses cumulative paracetamol exposure and NSAID complications.