Pain Management for FNP Boards: Opioids, Non-Opioids, and the WHO Ladder

Pharmacology · 9 min read · April 21, 2026

The WHO Pain Ladder

The World Health Organization analgesic ladder provides a stepwise approach to pain management:

Step 1 (Mild pain): Non-opioid analgesics ± adjuvants

  • Acetaminophen, NSAIDs, topical agents

Step 2 (Moderate pain): Weak opioids ± non-opioids ± adjuvants

  • Tramadol, codeine, hydrocodone (low dose)

Step 3 (Severe pain): Strong opioids ± non-opioids ± adjuvants

  • Morphine, oxycodone, hydromorphone, fentanyl

Non-Opioid Analgesics

Acetaminophen:

  • First-line for mild-moderate pain, OA, fever
  • Maximum dose: 4g/day (3g/day in elderly, liver disease, alcohol use)
  • Hepatotoxicity in overdose

NSAIDs (ibuprofen, naproxen, celecoxib):

  • Anti-inflammatory, analgesic, antipyretic
  • Risks: GI bleeding (add PPI if high risk), renal impairment, cardiovascular events
  • Avoid in: CKD, heart failure, elderly, pregnancy (third trimester)
  • Celecoxib (COX-2 selective): Less GI risk but still cardiovascular risk

Topical agents: Diclofenac gel, lidocaine patches, capsaicin — minimal systemic absorption, good for localized pain

Opioid Analgesics

Principles:

  • Start low, titrate slowly
  • Reassess regularly for efficacy and side effects
  • Prescribe naloxone for patients on chronic opioids
  • Use prescription drug monitoring programs (PDMPs)

Common opioids:

  • Morphine: Standard reference opioid
  • Oxycodone: Oral, available immediate and extended-release
  • Hydrocodone: Most commonly prescribed opioid in US
  • Tramadol: Weak opioid + SNRI; lower abuse potential; avoid in seizure disorders, serotonin syndrome risk
  • Fentanyl: Transdermal patch for chronic stable pain only (not acute pain)

Opioid side effects: Constipation (always prescribe bowel regimen), nausea, sedation, respiratory depression, pruritus

Opioid use disorder: Screen with CAGE-AID or ORT; consider buprenorphine/naloxone (Suboxone) for treatment

Adjuvant Analgesics

Neuropathic pain:

  • Gabapentin, pregabalin: First-line for diabetic neuropathy, postherpetic neuralgia
  • Duloxetine: FDA-approved for diabetic neuropathy, fibromyalgia, chronic musculoskeletal pain
  • TCAs (amitriptyline, nortriptyline): Effective but side effect burden in elderly

Fibromyalgia: Duloxetine, milnacipran, pregabalin (FDA-approved); exercise is also first-line

Board pearl: Opioids are NOT first-line for neuropathic pain or fibromyalgia. Start with non-opioid adjuvants.