Amitriptyline: Any Use For Neuropathic Pain?

Today's post from nzdoctor.co.nz (see link below) looks at the effectiveness of amitriptyline when taken for neuropathic pain and fibromyalgia. It's a standard first stage, treatment all over the world for neuropathic pain and has been for years but this tricyclic antidepressant has very often disappointed rather than worked. Apart from this, the side effects can be significant for some people. More and more commentators are questioning the use of amitriptyline for neuropathic purposes and the study mentioned here seem to suggest that they're right to do so. As it is one of the accepted first-line treatments in the doctor's handbooks, it may take some time before doctors world-wide choose not to prescribe it for their patients but patients should be aware of developments too.

Limited evidence for benefit of amitriptyline for neuropathic pain and fibromyalgia in adults
Wednesday 13 March 2013, 11:23AM

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


Clinical question

How effective is amitriptyline for neuropathic pain and fibromyalgia in adults?
Bottom line

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.

Context

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 Review

Moore 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.

http://www.nzdoctor.co.nz/gp-resources/pearls/2013/march-2013/13/limited-evidence-for-benefit-of-amitriptyline-for-neuropathic-pain-and-fibromyalgia-in-adults.aspx