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Pain Management Overview

Sep 3, 2025

Overview

This lecture reviews pain management concepts, covering medications for acute and chronic pain, evidence for their use, considerations in special scenarios like sports injuries, and approaches to migraines and neuropathic pain.

Pain Basics and Types

  • Pain treatment is individualized; response to medications can't be predicted in advance.
  • Common analgesics include acetaminophen (paracetamol), NSAIDs (ibuprofen, naproxen), COX-2 inhibitors, and topical NSAIDs.
  • Pain types discussed: acute pain, osteoarthritis (chronic pain), migraine, acute gout, neuropathic pain.

Acetaminophen and NSAIDs

  • Acetaminophen is effective for acute pain: about 50% achieve at least 50% relief, 30% benefit due to drug over placebo.
  • For acute migraine, acetaminophen is superior to placebo but doesn't help everyone; NNTs for pain relief range 5–12.
  • In children, ibuprofen may be slightly better than acetaminophen, but the difference is minor.
  • For chronic pain (e.g., osteoarthritis), NSAIDs are about 10% more effective than acetaminophen but have greater toxicity.
  • Regular, long-term NSAID use increases risk of GI bleeds (~1–2% per year), especially in elderly or high-risk.
  • Max safe acetaminophen dose: 4g/day (8x500mg), with lower doses for those with liver disease/alcoholism.

Topical NSAIDs and Sports Injuries

  • Topical NSAIDs are as effective for pain as oral NSAIDs, especially for single joints, with fewer systemic side effects.
  • Topical side effects are mainly skin-related.
  • NSAIDs do not reduce inflammation in acute sports injuries and may impair healing; acetaminophen is as effective for pain.
  • Treating fever: treat for comfort, not just to reduce temperature.

NSAID Safety, COX-2 Inhibitors, and Adverse Effects

  • COX-2 inhibitors (e.g., celecoxib) are not significantly safer or more effective than traditional NSAIDs.
  • NSAIDs can cause hypertension, edema, confusion (elderly), and worsen heart failure due to kidney effects.
  • No evidence that NSAIDs slow joint disease progression; they are for pain control only.
  • Enteric coating does not reduce GI risks; lowest effective dose should be used.

Headaches and Migraine Management

  • Many medications (including amitriptyline) can cause or worsen headaches.
  • For tension headaches and mild migraines, NSAIDs and acetaminophen are equally effective.
  • Aspirin, ibuprofen, and sumatriptan have similar effectiveness for acute migraines.
  • Combination products (aspirin + acetaminophen + caffeine) give best responses (~40% absolute benefit).
  • Sumatriptan and similar drugs: 60% response at 2 hours, can cause recurrence of headache in 30%.
  • Narcotics may be considered for intractable migraines but are not first-line.

Neuropathic Pain

  • Gabapentin and similar drugs benefit 1 in 6–8 patients, but have equal rates of side effects.
  • Start low with dosing; high doses increase side effects without clear added benefit.
  • Other options: tricyclic antidepressants, other anticonvulsants; overall modest efficacy.

Preventive Therapy for Migraines

  • Candidates: frequent or disabling migraines, patient preference.
  • Preventive meds (beta blockers, calcium channel blockers, certain antidepressants, supplements) reduce headache frequency by about 20–25% above placebo.
  • Low doses recommended; effect may take 2–3 months to assess.
  • Frequent reassessment is important due to changes over time.

Key Terms & Definitions

  • Acetaminophen (Paracetamol) — Common analgesic/antipyretic with low side effect profile, especially for acute pain.
  • NSAIDs — Non-steroidal anti-inflammatory drugs for pain/inflammation, but with GI, renal, and cardiovascular risks.
  • COX-2 Inhibitors — Subclass of NSAIDs thought to reduce GI toxicity, but not clearly safer overall.
  • Topical NSAIDs — NSAIDs applied to skin, effective for localized pain with fewer systemic effects.
  • Neuropathic Pain — Pain due to nerve damage, best treated with drugs like gabapentin or tricyclics.
  • Migraine Prophylaxis — Preventive medications to reduce frequency and severity of migraines.

Action Items / Next Steps

  • Review most recent guidelines for pain and migraine management.
  • Develop individualized pain plans considering patient history and risk factors.
  • For migraine patients, encourage headache diaries to monitor frequency and respond to preventive therapy.
  • Educate patients on maximum safe acetaminophen/NSAID doses and when to seek help for side effects.

Full transcript