Related Subjects:
|Analgesia and Pain management
|Sedation and Analgesia on ITU
|Neuropathic Pain Management
|Codeine
|Dihydrocodeine
|Diamorphine
|Morphine
📖 About Neuropathic Pain Management
- Neuropathic pain arises from nerve damage anywhere along the sensory pathway (peripheral nerves, spinal cord, or brain).
- Unlike nociceptive pain, it does not respond well to standard analgesics (e.g. paracetamol, NSAIDs).
- Management requires multimodal therapy (pharmacological, topical, physical, and psychological support).
🩺 Aetiology
- Diabetes mellitus (diabetic peripheral neuropathy).
- Alcohol misuse (nutritional deficiency, direct toxicity).
- Thalamic stroke (central post-stroke pain).
- Idiopathic or post-herpetic neuralgia.
- Other: chemotherapy-induced neuropathy, trauma, multiple sclerosis.
⚡ Clinical Features
- “Pins and needles” paraesthesia.
- Burning or electric shock–like sensations.
- Allodynia: pain evoked by normally non-painful stimuli (e.g. light touch).
- Hyperalgesia: exaggerated pain response to painful stimuli.
- Skin colour or trophic changes.
- Often worse at night, interfering with sleep and mood.
🔍 Investigations
- Exclude diabetes (Fasting glucose, HbA1c).
- Screen for systemic causes: FBC, U&E, CRP, B12, folate, thyroid function.
- Consider neuroimaging (e.g. MRI brain/spine) if central lesion suspected.
🩹 First-Line Pharmacological Management
- Duloxetine (esp. for diabetic neuropathy): start 60 mg OD, titrate to max 120 mg/day.
- Amitriptyline: start 10 mg nocte, increase by 10 mg weekly up to 75 mg/day (divided or nocte). Trial at max tolerated dose for ≥4 weeks before judging benefit.
- Gabapentin: start 100–300 mg nocte (frail: 100 mg), titrate gradually to max 1800 mg/day (divided TDS). Assess effect after 2 weeks at tolerated max. ~30–40% pain relief is significant.
- Pregabalin: start 75 mg nocte, ↑ to 75 mg BD if tolerated, max 600 mg/day (BD). Assess after 2–4 weeks at max tolerated dose.
🎯 Focal Neuropathic Pain
- Lidocaine 5% plaster (Versatis): applied locally to affected dermatomes (e.g. post-herpetic neuralgia).
- Capsaicin cream 0.075% (Axsain): depletes substance P in sensory nerves, used in localised neuropathic pain.
💡 Specific Syndromes
- Diabetic Peripheral Neuropathy: Duloxetine first-line; pregabalin or amitriptyline if not tolerated.
- Post-Herpetic Neuralgia: Lidocaine plasters, gabapentinoids, or tricyclics.
- Trigeminal Neuralgia: Carbamazepine remains the drug of choice; consider oxcarbazepine if not tolerated.
📝 Clinical Pearls
- Neuropathic pain drugs rarely abolish pain → goal is ≥30–40% reduction and improved function/sleep.
- Always start low, go slow, and assess efficacy at the maximum tolerated dose before switching.
- Combination therapy may be considered if monotherapy is insufficient.
- Opioids (e.g. tramadol, oxycodone) are third-line and specialist-only due to dependence risks.
- Non-pharmacological strategies (CBT, physiotherapy, TENS, sleep hygiene) should always be part of management.
📚 References
