The WHO Analgesic Ladder is a stepwise framework, originally developed in 1986 for cancer pain management, that guides drug selection based on pain severity. Treatment starts at the step matching the patient's pain intensity and escalates if pain is not controlled - "non-opioids, followed by weak and then strong opioids, and finally referral to a pain clinic" (Bailey and Love's Short Practice of Surgery, p. 6722-6732).

Step 1 - Mild pain (score 1-3/10): Non-opioid analgesics - paracetamol (acetaminophen) and/or NSAIDs (e.g. aspirin, ibuprofen) - with or without an adjuvant (e.g. antidepressant, anticonvulsant, corticosteroid for neuropathic or bone pain) (Cummings Otolaryngology, p. 570-575).

Step 2 - Mild to moderate pain (score 4-6/10): A weak opioid (e.g. codeine, tramadol, dihydrocodeine) added to a step 1 non-opioid, ± adjuvant. Weak opioids are "used for mild to moderate pain, often in combination with step 1" agents (Cummings Otolaryngology, p. 640-642).

Step 3 - Moderate to severe pain (score 7-10/10): A strong opioid (e.g. morphine, oxycodone, fentanyl, hydromorphone) replaces the weak opioid, continuing the non-opioid ± adjuvant, with individual dose titration to effect (Cummings Otolaryngology, p. 570).

Note/limitation: The ladder is a guide rather than a rigid protocol - it is not always in the patient's absolute best interest to strictly follow all three steps sequentially, and some patients with severe pain may need to start directly at step 3 (Swanson's Family Medicine Review, p. 8279-8290). Its continued validity for all pain types (especially neuropathic pain) has also been questioned in more recent literature (Scott-Brown's Otorhinolaryngology, p. 5064-5083).