Tricylic antidepressants for neuropathic pain

The trials of tricyclic antidepressants in neuropathic pain have concentrated mainly on:

• post-herpetic neuralgia
• diabetic sensory polyneuropathy

Most studies use a visual analogue scale to rate pain.

In most studies one of the endpoints was achieving a 50% reduction in perceived pain.

Tricyclic antidepressants (TCAs) are effective treatments for the treatment of neuropathic pain (2)

• amitriptyline has an NNT of 2 (95%CI 1.7 to 2.5) for the achievement of at least moderate pain relief
• for diabetic neuropathy the NNT for effectiveness was 1.3 (95%CI 1.2 to 1.5)
• for postherpetic neuralgia 2.2 (95%CI 1.7 to 3.1)

NICE suggest:

• with respect to neuropathic pain (3):
  • offer a choice of amitriptyline, duloxetine, gabapentin or pregabalin as initial treatment for neuropathic pain (except trigeminal neuralgia)
    • for amitriptyline previous guidance stated (4)
      • start at 10 mg per day, with gradual upward titration to an effective dose or the person's maximum tolerated dose of no higher than 75 mg per day (higher doses could be considered in consultation with a specialist pain service)
• with respect to painful diabetic neuropathy:
  • for people with painful diabetic neuropathy, offer oral duloxetine as first-line treatment. If duloxetine is contraindicated, offer oral amitriptyline

Reference:

1. Drug and Therapeutics Bulletin 2000;38(12):89-93.
2. Saarto T, Wiffen PJ. Antidepressants for neuropathic pain. Cochrane Database Syst Rev 2005;(3):CD005454.
3. NICE (April 2018). Neuropathic pain (adults) - pharmacological management
4. NICE (March 2010). Neuropathic pain (adults) - pharmacological management