382: Limited evidence for benefit of amitriptyline for neuropathic pain and fibromyalgia in adults

March 17, 2013

PEARLS 382, February 2013, written by Brian R McAvoy.

Clinical question
How effective is amitriptyline for neuropathic pain and fibromyalgia in adults?

Amitriptyline probably does not work in neuropathic pain associated with HIV or treatments for cancer. Amitriptyline probably does work in other types of neuropathic pain (painful diabetic neuropathy, post-herpetic neuralgia, and post-stroke pain, and in fibromyalgia), though we cannot be certain of this. A best estimate is that amitriptyline provides pain relief in about 1 in 4 (25%) more people than does placebo (NNT* = 4.6 [95% confidence interval 3.6Ð6.6]), and about 1 in 4 (25%) more people than placebo report having at least 1 adverse event, probably not serious but disconcerting.*NNT = number needed to treat to benefit 1 individual.

Caveat
There were no studies that could provide an answer that was trustworthy or reliable because most studies were relatively old, and used methods or reported results that we now recognise can make benefits seem better than they are.

Amitriptyline is a tricyclic antidepressant that is widely used to treat chronic neuropathic pain and fibromyalgia, and is recommended in many guidelines. These types of pain can be treated with antidepressant drugs in doses below those at which the drugs act as antidepressants.

Cochrane Systematic ReviewMoore RA et al. Amitriptyline for neuropathic pain and fibromyalgia in adults. Cochrane Reviews, 2012, Issue 12. Art. No.: CD008242.DOI: 10.1002/14651858. CD008242.pub2.

This review contains 21 studies involving 1437 participants.

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.