Pain management • WHO analgesic ladder • Pharmacological and non-drug care • Palliative emergencies

Principles of Pain Management and the WHO Analgesic Ladder

A detailed, safety-focused guide for emergency medicine and palliative-care students

Learning objectives

• State the goals and principles of comprehensive pain management.
• Use the WHO analgesic ladder as a flexible framework rather than an automatic prescription.
• Select non-opioids, opioids and adjuvants according to pain mechanism, severity, function, comorbidity and goals.
• Describe common adult examples, indications, contraindications, adverse effects, interactions and monitoring requirements.
• Plan emergency, hospital, nursing, home-care and follow-up management.
• Recognize opioid toxicity, uncontrolled pain and reversible pain emergencies.

1. What successful pain management aims to achieve

The goal is not simply a lower number. A useful plan relieves suffering, restores meaningful function, treats the cause when appropriate, minimizes harm and respects the person’s values.

1. Relieve pain to a tolerable level agreed with the patient.
2. Enable breathing, sleep, movement, feeding, communication and meaningful activities.
3. Treat reversible causes such as infection, fracture, obstruction, constipation, urinary retention, pressure injury or nerve compression.
4. Match treatment to mechanism: nociceptive, neuropathic, nociplastic or mixed.
5. Prevent predictable pain, including incident, procedural and end-of-dose pain.
6. Prevent and promptly manage adverse effects and medication errors.
7. Support psychological, social, spiritual and caregiver needs—the dimensions of total pain.
8. Review goals when disease, function, prognosis or patient preference changes.

2. First contact: a logical emergency approach

Step	Action	Reason
1. Safety and ABCDE	Assess airway, breathing, circulation, disability and exposure. Check vital signs, glucose when indicated and immediate red flags.	Pain may accompany shock, sepsis, myocardial infarction, stroke, compartment syndrome, spinal compression or major bleeding.
2. Rapid pain screen	Ask site, onset, severity/tool, quality, associated symptoms, current medicines and the patient’s immediate goal.	Provides enough information to treat distress while the full assessment continues.
3. Immediate comfort	Position safely, support an injured limb, reduce stimulation, cover wounds, provide oxygen only when indicated and offer calm explanation.	Non-drug measures reduce distress and may prevent worsening.
4. Analgesia and monitoring	Give the locally approved medicine appropriate to the cause and risk; document route, time and dose; monitor response and adverse effects.	Untreated severe pain causes physiological and psychological harm, but medicines also carry risk.
5. Investigate and escalate	Target tests to the history/examination; call senior, surgical, obstetric, anaesthetic, oncology, palliative or mental-health support as needed.	Analgesia treats a symptom; definitive care may be time-critical.
6. Reassess	Repeat the same pain tool and focused examination after intervention or a clinically appropriate interval.	Failure to improve, new signs or toxicity requires a changed plan.

3. Core principles of the WHO analgesic ladder

The supplied reference summarizes the classic three-step ladder:

1. Step 1: non-opioid analgesic, with or without an adjuvant, for mild pain.
2. Step 2: a weak opioid plus or minus a non-opioid and adjuvant for mild-to-moderate pain.
3. Step 3: a strong opioid plus or minus a non-opioid and adjuvant for moderate-to-severe pain.

Modern nuance: the ladder is a teaching framework, not a rigid sequence or a justification for under-treating severe pain. A strong opioid may be clinically appropriate at presentation, while neuropathic, inflammatory, bone, visceral and psychosocial contributors require additional targeted treatment. Always apply the current WHO guidance and local protocol.

4. Non-opioid analgesics

4.1 Paracetamol (acetaminophen)

Aspect	Key points
Role	Useful for mild-to-moderate nociceptive pain and fever; may provide additive benefit with an opioid. Predominantly central action and little anti-inflammatory effect.
Common adult example	500–1,000 mg orally every 6 hours as needed or regularly; many formularies use a maximum of 4 g/day in healthy adults. Use a lower maximum (often 3 g/day or less) in low body weight, malnutrition, chronic alcohol use, liver disease or frailty according to local guidance.
Contraindications/cautions	Severe active liver disease, significant overdose risk, heavy alcohol use, malnutrition and duplicate combination products.
Adverse effects	Usually well tolerated at therapeutic doses; overdose can cause delayed severe hepatic injury even before symptoms appear.
Interactions	Check combination cold/flu and opioid products; repeated high doses may affect anticoagulant control in some patients.
Monitoring	Total daily dose from every source, liver risk, treatment response and any overdose concern. Suspected overdose is an emergency.

4.2 NSAIDs

Ibuprofen, naproxen and diclofenac inhibit cyclo-oxygenase and reduce prostaglandin synthesis. They are most useful when inflammation, bone pain, arthritis, pleural pain or soft-tissue injury contributes. COX-2 selective agents may reduce gastrointestinal toxicity but can increase cardiovascular risk.

Example adult dose (verify locally)	Important cautions
Ibuprofen: 200–400 mg orally every 6–8 hours; do not exceed the local maximum (commonly 1,200 mg/day without prescription and up to 2,400 mg/day under supervision).	Avoid or obtain senior advice in dehydration, active ulcer/bleeding, severe renal disease, uncontrolled hypertension, heart failure, significant cardiovascular disease, NSAID allergy/asthma, anticoagulation and late pregnancy.
Naproxen: 250–500 mg orally twice daily with food; use the lowest effective dose for the shortest time.	Same gastrointestinal, renal, cardiovascular and pregnancy cautions; consider gastroprotection when risk is high.
Diclofenac: 25–50 mg orally two or three times daily, maximum commonly 150 mg/day; follow local formulation guidance.	Particular cardiovascular, renal and gastrointestinal risk; avoid combining with another NSAID.

• Check renal function, hydration, blood pressure, heart failure, ulcer history, bleeding risk and concomitant medicines.
• Do not combine two NSAIDs. Avoid routine NSAIDs in severe kidney disease or high-risk cardiovascular disease.
• Consider a proton-pump inhibitor for gastrointestinal protection when indicated by local guidance.
• Monitor dyspepsia, melaena, haematemesis, reduced urine, oedema, breathlessness and blood pressure.

5. Opioid analgesics

Opioids act mainly at mu receptors in the brain, spinal cord and peripheral tissues. They are effective for moderate-to-severe nociceptive pain and some mixed cancer pain, but require individualized titration and monitoring. They do not reliably treat neuropathic pain alone.

5.1 Weak or intermediate opioids

Medicine	Educational example and role	Main cautions
Codeine	Often combined with paracetamol; local adult schedules commonly use 15–60 mg every 4–6 hours with a daily maximum set by the formulary.	Variable CYP2D6 metabolism, constipation, nausea, sedation and respiratory depression. Avoid in severe respiratory disease and use caution in children, older adults and breastfeeding.
Tramadol	Common adult example 50–100 mg every 4–6 hours, with a usual maximum of 400 mg/day; reduce in older age, renal/hepatic impairment and according to local protocol.	Seizure risk, serotonin syndrome with serotonergic medicines, nausea, dizziness, hypoglycaemia, dependence and respiratory depression. Avoid or seek specialist advice with MAOIs and significant seizure risk.

Weak opioids may have a ceiling from adverse effects and are not automatically safer than carefully used strong opioids. Tramadol’s serotonergic and noradrenergic actions create interaction risks. Do not combine multiple opioid products without a deliberate prescribing plan.

5.2 Morphine: a strong opioid example

Aspect	Key points
Indications	Moderate-to-severe acute or persistent pain, cancer pain and palliative pain when a strong opioid is appropriate.
Opioid-naive adult example	Immediate-release oral morphine is often started at 2.5–5 mg every 4 hours in frail or opioid-naive adults, with a rescue dose and titration under local protocol. Some adults require a different starting dose; never copy a dose without checking formulation and risk.
Rescue principle	A breakthrough dose is commonly a proportion of the total regular 24-hour dose, often around one-sixth, but this must be calculated and approved by a trained prescriber.
Contraindications/cautions	Significant respiratory depression, acute severe asthma without monitoring, paralytic ileus, severe renal impairment, raised intracranial pressure, frailty, sleep apnoea and concurrent sedatives.
Adverse effects	Constipation, nausea/vomiting, pruritus, urinary retention, sedation, confusion, falls, hypotension and respiratory depression. Tolerance and physical dependence differ from addiction.
Interactions	Alcohol, benzodiazepines, sedating antihistamines, gabapentinoids and other CNS depressants increase sedation and respiratory risk. Renal impairment causes active-metabolite accumulation.
Monitoring	Pain and function, respiratory rate and effort, sedation score, mental state, blood pressure, nausea, bowel function, urine and falls. Provide a bowel plan unless contraindicated.

Opioid toxicity: increasing drowsiness, inability to wake, slow or shallow breathing, pinpoint pupils, cyanosis or severe hypotension require immediate airway/breathing support, senior help and the local naloxone protocol. Do not leave an oversedated patient alone.

5.3 Fentanyl and methadone

• Fentanyl: potent opioid available in parenteral and transdermal forms. Transdermal patches are for stable opioid requirements, not rapid titration or opioid-naive emergency patients. Heat, fever, cachexia, dosing errors and patch duplication can cause fatal overdose. Follow local conversion guidance and document patch location and removal.
• Methadone: specialist medicine with long and variable half-life, complex conversion, drug interactions and potential QT prolongation. Initiate or rotate only with experienced oversight, ECG and local protocol where indicated.

6. Adjuvant analgesics and mechanism-directed treatment

An adjuvant is a medicine primarily used for another indication that improves pain or treats a related symptom. It may be used alone or with an analgesic. Select it for a defined mechanism or complication, not simply because pain is difficult.

Adjuvant/class	Indications	Common adult educational examples	Key risks/monitoring
Tricyclic antidepressants (amitriptyline, nortriptyline)	Neuropathic pain, sleep disturbance; sometimes visceral neuropathic pain.	Amitriptyline 10–25 mg at night, titrate slowly; specialist/local maximum often 75–100 mg/day.	Dry mouth, constipation, urinary retention, blurred vision, orthostatic hypotension, sedation, falls, delirium and QT/arrhythmia risk. Avoid in significant conduction disease and use caution with anticholinergics.
SNRIs (duloxetine)	Diabetic neuropathy and some chronic neuropathic pain with mood symptoms.	30 mg daily initially, often 60 mg daily if tolerated.	Nausea, dizziness, insomnia or somnolence, blood-pressure change, serotonin syndrome and withdrawal symptoms. Avoid severe liver disease and use caution in renal impairment or with serotonergic medicines.
Gabapentin	Neuropathic pain, allodynia and selected palliative pain.	Start low, e.g., 100–300 mg at night, then titrate gradually to divided doses according to renal function and local protocol.	Somnolence, dizziness, ataxia, oedema, falls and respiratory depression with opioids or lung disease. Renally clear; adjust dose.
Pregabalin	Neuropathic pain and selected anxiety/sleep symptoms.	Often 25–75 mg at night or twice daily initially, titrated cautiously; renal adjustment required.	Dizziness, sedation, oedema, blurred vision, weight gain, mood change, misuse and respiratory depression with opioids.
Corticosteroids (dexamethasone)	Inflammatory pain, nerve compression, raised intracranial pressure, capsular liver pain, appetite or nausea in selected cases.	Indication-specific; commonly 2–8 mg each morning for a short course under specialist/local guidance.	Hyperglycaemia, infection, delirium, insomnia, proximal weakness, dyspepsia and adrenal suppression. Review and taper when prolonged.
Antispasmodics	Colicky visceral pain or secretions in selected palliative situations.	Medicine and dose depend on cause and local formulary.	Anticholinergic delirium, urinary retention, dry mouth, glaucoma risk and tachycardia.
Muscle relaxants	Selected muscle spasm or spasticity after cause assessment.	Specialist/local protocol; avoid casual benzodiazepine use.	Sedation, falls, respiratory depression and dependence, especially with opioids.
Ketamine	Specialist rescue for refractory pain, severe central sensitization or opioid-resistant pain.	Sub-anaesthetic dosing requires specialist prescription, monitoring and a clear endpoint.	Hallucinations, dysphoria, hypertension, nausea, excessive sedation and misuse; avoid unsupervised use.
Local anaesthetic techniques	Focal neuropathic pain, procedures, nerve blocks or regional analgesia.	Lidocaine or regional/epidural techniques only by trained clinicians with monitoring.	Systemic toxicity: perioral numbness, tinnitus, metallic taste, seizures, arrhythmia or cardiovascular collapse.

Other cause-directed adjuvants may include antibiotics for infection, anticonvulsants for seizures, bisphosphonates or radiotherapy for selected bone metastases, laxatives for opioid constipation and antiemetics for nausea. They do not replace a diagnostic assessment.

7. Non-pharmacological pain management

Intervention	Examples and mechanism	Safety considerations
Therapeutic relationship	Empathy, counselling, truthful explanation, reassurance without false promises and shared goals.	Do not use communication to dismiss pain or delay treatment.
Positioning and support	Elevation, splinting, pressure relief, pillows, mobility aids and safe transfers.	Check circulation, skin, neurovascular status and falls risk.
Heat or cold	Short, protected applications for selected muscle or inflammatory pain.	Avoid burns, impaired sensation, poor circulation, open wounds and prolonged exposure.
Physiotherapy and exercise	Gentle movement, stretching, strengthening, breathing and functional rehabilitation.	Match to diagnosis; stop for acute deterioration or neurovascular change.
TENS or other modalities	May reduce some musculoskeletal or neuropathic pain through sensory modulation.	Follow trained use; caution with pacemakers, skin breakdown and impaired sensation.
Psychological methods	Relaxation, breathing, mindfulness, CBT, guided imagery, distraction and sleep support.	Use as adjuncts, not as proof that pain is psychological.
Spiritual and social support	Chosen faith leader, reconciliation, family support, social work, transport and financial assistance.	Ask permission and respect confidentiality and cultural safety.
Specialist procedures	Nerve blocks, epidural/intrathecal analgesia, radiotherapy or surgery for selected causes.	Require appropriate referral, consent, monitoring and risk–benefit discussion.

8. Hospital management workflow

1. Confirm safety and cause: complete primary survey, pain history, examination and targeted investigations.
2. Set goals: agree on intensity, function, sleep, breathing or comfort goals and whether care is restorative, palliative or both.
3. Start proportionate treatment: choose route and medicine based on severity, mechanism, comorbidities and monitoring capacity.
4. Prevent predictable adverse effects: bowel regimen with opioids, antiemetic where indicated, hydration review, falls precautions and medicine reconciliation.
5. Reassess: repeat the pain tool and vital/neurological assessment at a defined interval; evaluate sedation and function.
6. Escalate intelligently: address an untreated cause, add a mechanism-specific adjuvant, involve a specialist or change route—not merely repeated ineffective doses.
7. Plan discharge: named prescriber, written schedule, rescue instructions, storage, caregiver teach-back, warning signs, review date and contact number.

9. Nursing responsibilities

• Assess and record pain at admission, after procedures, at regular review and whenever the patient reports a change.
• Use the patient’s preferred validated tool and record rest/movement scores.
• Administer medicines safely: right patient, medicine, dose, route, time, indication, allergies and documentation.
• Monitor respiratory rate, sedation, blood pressure, nausea, vomiting, bowel function, urine, itching, confusion, falls and functional response.
• Implement positioning, pressure relief, wound support, quiet environment, relaxation, sleep and family education.
• Check that the patient and caregiver can explain the plan, identify adverse effects and know when to call.
• Escalate uncontrolled pain, new red flags, opioid toxicity, unsafe home conditions or safeguarding concerns.
• Handover the mechanism suspected, tool/score trend, interventions, response, pending tests and escalation threshold.

10. Prevention of recurrent and avoidable pain

• Anticipate procedure, dressing, movement, feeding, physiotherapy and incident pain; plan before the trigger.
• Turn and reposition safely, protect skin and prevent pressure injury.
• Prevent constipation, urinary retention, dehydration and medication withdrawal where relevant.
• Reconcile medicines at every transition and remove duplicate paracetamol, NSAID or opioid products.
• Teach safe lifting, mobility and use of assistive devices.
• Address sleep, anxiety, depression, isolation, stigma, financial barriers and caregiver exhaustion early.
• Provide a written safety net and an accessible route for review rather than advising patients to wait until pain is unbearable.

11. Special safety points

Renal or hepatic impairment

Review paracetamol maximum, NSAID suitability, opioid metabolites and adjuvant clearance. Start lower, increase more slowly and seek senior or palliative/pharmacy advice. Avoid assuming that a standard adult dose is safe.

Older adults and frailty

Use “start low, go slow, but go” when a treatment is indicated. Monitor delirium, sedation, falls, constipation, renal function and polypharmacy.

Pregnancy and breastfeeding

Confirm pregnancy status when relevant and use current obstetric guidance. Do not extrapolate routine adult dosing without specialist advice.

Substance-use history

Assess pain without stigma while using clear prescribing, monitoring, storage and follow-up. Distinguish tolerance, physical dependence, opioid-induced hyperalgesia, withdrawal and opioid use disorder.

Children

Use weight-based, age-appropriate protocols and formulations; never copy adult doses. Check concentration carefully, especially liquid products.

12. When pain remains uncontrolled

1. Repeat the diagnosis and examine for a new emergency.
2. Confirm adherence, administration, absorption, route, formulation and drug interactions.
3. Identify the dominant mechanism or mixed mechanisms.
4. Look for opioid-induced hyperalgesia, withdrawal, delirium, constipation, urinary retention, infection, anxiety or uncontrolled existential distress.
5. Ask about function and goals rather than escalating toward an arbitrary score.
6. Seek specialist palliative, pain, anaesthetic, oncology, neurology, surgical or mental-health input.
7. Consider regional techniques, radiotherapy, surgery, disease-modifying treatment or a carefully supervised opioid rotation where indicated.

13. Patient and caregiver education

• Explain what each medicine is for, how and when to take it, expected effects, serious warning signs and what to do if a dose is missed.
• Use one written medicine list and keep opioids and sedatives securely stored away from children and unintended users.
• Explain that constipation is common with opioids and requires prevention and review; report severe abdominal pain, vomiting or inability to pass stool/gas.
• Warn against alcohol and unapproved sedatives with opioids or gabapentinoids.
• Use teach-back: “Please show me how you will use this plan tonight and when you would call for help.”
• Give a named contact, follow-up time and specific red flags rather than “return if worse.”

14. Clinical cases

15. Quick self-test

1. State the four traditional rules of the WHO ladder.
2. When might a strong opioid be appropriate without prolonged use of a weak opioid?
3. Name three major opioid adverse effects and their prevention/monitoring measures.
4. Give two indications and two cautions for NSAIDs.
5. Name three adjuvant classes for neuropathic pain and one important safety concern for each.
6. What should happen when pain remains uncontrolled despite repeated doses?

Answers

1. By the mouth, by the clock, by the ladder and for the individual.
2. Severe pain, severe disease, ineffective step-2 treatment or a clinical need for rapid strong analgesia—under an individualized monitored plan.
3. Constipation (prevent and monitor bowel function), nausea/vomiting (review and treat), sedation/respiratory depression (monitor consciousness and breathing), confusion/falls (reassess dose and risks).
4. Indications include inflammatory, bone or musculoskeletal pain. Cautions include renal disease/dehydration, ulcer or bleeding, heart failure/cardiovascular disease, hypertension, allergy and pregnancy.
5. Examples: amitriptyline—anticholinergic effects/QT and falls; gabapentin—sedation, oedema and renal clearance; duloxetine—serotonergic effects and liver/renal cautions; corticosteroids—hyperglycaemia, infection and delirium.
6. Repeat assessment and diagnosis, check administration and interactions, identify mechanism and reversible causes, then escalate to senior/specialist care rather than blindly increasing a dose.

Key take-home points

• Effective pain management is multimodal, mechanism-based, goal-directed and repeatedly reassessed.
• The WHO ladder is a flexible framework; severe pain may require a strong opioid promptly, while adjuvants and cause-directed treatment remain essential.
• “By the mouth, by the clock, by the ladder, for the individual” remains a useful memory aid, but current local guidance governs prescribing.
• Always pair analgesia with monitoring, bowel and safety planning, patient education and documented follow-up.
• Uncontrolled, new or changing pain is a reason to reassess the diagnosis—not simply to increase medicine.

Further study and references

• Comprehensive Pain Management Using WHO Analgesic Ladder and Adjuvant Therapies — supplied Slideshare reference
• WHO guideline for the pharmacological and radiotherapeutic management of cancer pain
• WHO: Palliative care
• NICE: Neuropathic pain in adults
• Related lesson: Description, classification and physiology of pain
• Related lesson: Using pain-assessment tools

Educational resource for supervised learning. Confirm every prescription against the current Uganda formulary, controlled-medicines requirements and senior clinical advice.