Medication for neuropathic pain

What is Neuropathic Pain (NeP)?

  • "Pain initiated or caused by a primary lesion or dysfunction in the nervous system” (IASP 1997).
  • NeP is very different from nociceptive (inflammatory pain). While nocioceptive pain is due to tissue destruction, NeP is due to abnormally functioning nerves due to numerous causes.

How common is Neuropathic Pain?

  • It is thought to affect 2-4% of the general population (1-2 million people suffer with neuropathic pain in the UK)
  • It can affect up to 20-25% of diabetic patients and 30-40% of patients with cancer
  • The average GP may have 35-70 patients suffering with neuropathic pain

Neuropathic Symptoms

  • Primary - pain
    • Can be spontaneous or evoked, continuous or intermittent
    • Trigger words to aid diagnosis "burning, shooting, stabbing" (see DN4 tool)
  • Secondary - co-morbidity
    • Sleep interference, lack energy, drowsiness, concentration/memory difficulties, mood swings, depression, anxiety, physical disability

Neuropathic Symptoms

  • Allodynia: pain produced by an innocuous stimulus e.g. touch, pressure
  • Hyperaesthesia: increased sensitivity to touch
  • Hyperalgesia: increased response to stimulus which is normally painful
  • Dysaesthesia: an unpleasant abnormal sensation

Pathway for managing Neuropathic pain in primary care

  • This is a new guideline with resources for both patient and clinician to manage long term neuropathic pain. It covers both post herpetic neuralgia and neuropathic pain.
  • Use this treatment guidance and the resources before considering referral.
  • If complex regional pain syndrome is suspected, refer early to pain specialist team. (see guidance)
  • The Neuropathic pain diagnostic DN4 tool is useful to aid diagnosis and for detecting change in pain after treatment. (see patient clinical resources on pathway)
  • All of the drugs in the guideline can cause significant adverse effects in some patients. If this occurs, try an alternative from the same therapeutic group. For example, with tricyclic antidepressants (TCA) try nortriptyline or imipramine instead of amitriptyline. Use patient leaflets provided to guide patients in their effective use.