365.4 📋 章末速蚘 Summary

365.4.1 🔑 䞀句話瞜結

Pain = unpleasant sensory + emotional experience (IASP 2020 revised); acute vs chronic > 3 months; three pain types — nociceptive (somatic, visceral) vs neuropathic (peripheral DM/PHN/CIPN/radiculopathy, central post-stroke/MS/SCI — burning, electric, lancinating, allodynia) vs nociplastic (altered nociception without clear damage — fibromyalgia, IBS, TMD, central sensitization); WHO analgesic ladder Step 1 mild (acetaminophen + NSAIDs + adjuvants) → Step 2 moderate (weak opioid tramadol/codeine + non-opioid + adjuvant) → Step 3 severe (strong opioid morphine/oxycodone/hydromorphone/fentanyl/methadone + non-opioid + adjuvant); opioid crisis era has shifted prescribing toward multimodal + opioid minimization + non-opioid alternatives (suzetrigine NaV1.8 FDA Jan 2025 for acute post-op pain); neuropathic pain first-line — gabapentin (300-3600 mg/d) + pregabalin (150-600 mg/d) + duloxetine (60-120 mg) + venlafaxine + TCA (amitriptyline, nortriptyline) + topical lidocaine 5% patch + capsaicin 8% patch; trigeminal neuralgia carbamazepine first-line + oxcarbazepine + microvascular decompression; postherpetic neuralgia (PHN) — gabapentin/pregabalin/TCA/lidocaine patch + prevention with Shingrix recombinant zoster vaccine + early antivirals (valacyclovir); CRPS Type I/II — multimodal physical therapy + anti-neuropathic + sympathetic blocks; opioid pearls — equivalence morphine 30 mg PO = oxycodone 20 mg = hydromorphone 7.5 mg = fentanyl 12.5 ÎŒg/h patch; methadone NMDA effect useful for refractory neuropathic but QT + variable T1/2 require ECG monitoring + slow titration; side effects — constipation (tolerance doesn’t develop, prophylactic laxative) + sedation + respiratory depression + hyperalgesia (paradoxical) + endocrine hypogonadism; opioid use disorder (OUD) distinct from physical dependence — risk assessment (ORT, SOAPP, COMM) + PDMP + naloxone for overdose + MAT (buprenorphine, methadone, naltrexone); MME ≥ 50/d high risk + ≥ 90 very high risk; taper slowly ~ 10% per week; special populations — renal failure (avoid morphine M6G + codeine + meperidine; safe methadone, fentanyl, buprenorphine, hydromorphone caution); liver failure (↓ doses + ↑ intervals; acetaminophen 3 g/d max); fibromyalgia (nociplastic) — aerobic exercise + pregabalin + duloxetine + milnacipran (FDA-approved) + avoid opioids。

365.4.2 💊 治療粟芁

  • Step 1 mild: acetaminophen 1 g q6h max 4 g/d (3 g if liver disease) + NSAIDs (ibuprofen 400-800 mg q6-8h, naproxen 500 mg BID, celecoxib 200 mg BID, ketorolac IM)
  • Step 2 moderate: tramadol 50-100 mg q4-6h (seizure threshold, serotonergic interactions) + codeine + tapentadol
  • Step 3 severe: morphine (10-30 mg PO q4h, IV titrate) + oxycodone (5-10 mg PO q4-6h, ER form) + hydromorphone (2-4 mg PO q4-6h) + fentanyl transdermal patch (12.5-100 ÎŒg/h, change q72h) + methadone (3-10 mg PO TID, slow titration ECG QT)
  • Adjuvants: TCAs (amitriptyline 25-100 mg HS, nortriptyline less anticholinergic), SNRIs (duloxetine 60-120 mg, venlafaxine 75-225 mg ER), anticonvulsants (gabapentin titrate to 1800-3600 mg/d in 3 doses, pregabalin 150-600 mg/d in 2 doses, carbamazepine for TN), topical lidocaine 5% patch (PHN, focal), capsaicin 8% patch (60-min application, q3 months)
  • Neuropathic pain first-line: gabapentin/pregabalin or duloxetine/venlafaxine or TCA; second-line lidocaine/capsaicin patch + tramadol + selected opioids
  • Trigeminal neuralgia: carbamazepine 200-1200 mg/d; oxcarbazepine + lamotrigine + gabapentin; microvascular decompression (Janetta) for refractory
  • PHN prevention: Shingrix 2 doses ≥ 50 yo + early valacyclovir 1 g TID × 7 days for acute zoster
  • CRPS: aggressive physical therapy (cornerstone) + anti-neuropathic + sympathetic ganglion blocks + spinal cord stimulator for refractory
  • Opioid overdose: naloxone 0.4-2 mg IV/IM/IN (short T1/2 — re-narcotization possible, monitor)
  • MAT for OUD: buprenorphine (sublingual 8-24 mg/d, X-waiver eliminated 2023) + methadone (specialized program) + naltrexone (oral or LAI Vivitrol)
  • Tapering: ~ 10% per week slow taper; consider buprenorphine for high-dose chronic
  • Suzetrigine (Vertex VX-548) FDA Jan 2025 — selective NaV1.8 inhibitor, non-opioid for moderate-severe acute pain post-surgery

365.4.3 🎯 盧醫垫的考前提醒

  1. Three pain types (memorize): nociceptive (somatic, visceral) vs neuropathic (peripheral + central) vs nociplastic (fibromyalgia, central sensitization, less opioid-responsive) — treatment differs
  2. WHO analgesic ladder: Step 1 non-opioid + adjuvant → Step 2 weak opioid + non-opioid → Step 3 strong opioid + non-opioid; adjuvants throughout all steps
  3. Neuropathic pain first-line: gabapentinoids (gabapentin/pregabalin) + SNRIs (duloxetine/venlafaxine) + TCAs (amitriptyline/nortriptyline); second-line topical lidocaine/capsaicin + tramadol
  4. Trigeminal neuralgia: carbamazepine first-line (response is virtually diagnostic); microvascular decompression (Janetta) for refractory
  5. PHN prevention: Shingrix (recombinant zoster vaccine) ≥ 50 yo + early antivirals (valacyclovir 1 g TID × 7 days) for acute zoster reduce risk
  6. Opioid equivalence (memorize): morphine 30 mg PO = oxycodone 20 mg PO = hydromorphone 7.5 mg PO = fentanyl 12.5 ÎŒg/h TD = codeine 200 mg PO
  7. Opioid side effects: constipation (tolerance does NOT develop — prophylactic laxative) + sedation + respiratory depression + N/V + pruritus + hyperalgesia (paradoxical — pain ↑ with dose ↑, opioid rotation or taper) + endocrine hypogonadism
  8. Renal failure pain meds: avoid morphine (M6G accumulation) + codeine (active metabolites) + meperidine (normeperidine → seizures); safe — methadone, fentanyl, buprenorphine; hydromorphone caution
  9. Opioid use disorder vs physical dependence: distinct concepts; naloxone 0.4-2 mg IV/IM/IN for overdose (short T1/2 — monitor); MAT — buprenorphine (X-waiver eliminated 2023), methadone, naltrexone
  10. 2025 update: Suzetrigine (Vertex VX-548) FDA approved January 2025 — selective NaV1.8 sodium channel inhibitor, non-opioid for moderate-severe acute pain (post-surgery initial indication); first new mechanism in decades; fibromyalgia treated with exercise + pregabalin + duloxetine + milnacipran — avoid opioids