High Dose Amitriptyline not for Fibro

An article by Spanish researchers discussing amitriptyline as a treatment for Fibromyalgia Syndrome (Fibro) was this week e-published ahead of print in the journal Rheumatology. The researchers concluded that there was no evidence to support the use of amitriptyline for Fibro at higher doses or for longer than 8 weeks.

In order to assess the efficacy and safety of amitriptyline as a treatment for Fibro, a comprehensive computerized search in Medline (Pubmed), EMBASE and The Cochrane Library was carried out, looking for randomized controlled trials (RCTs) that compared amitriptyline vs placebo in adult patients suffering from Fibro. Ten study of moderate to high quality were identified, although the variability of the studies precluded a quantitative meta-analysis being carried out (i.e. the results could not simply be integrated).

Amitriptyline 25 mg/day (six RCTs) was found to be of benefit compared to placebo when considering pain, sleep, fatigue and overall patient and investigator impression. However, this benefit was generally seen at 6-8 weeks of treatment, with no benefit being noted at 12 weeks.

Amitriptyline 50 mg/day (four RCTs) did not demonstrate a benefit compared to placebo.

Neither dose of amitriptyline had an effect on the number of tender points the study participants were measured as having.

The researchers concluded that:

"A definitive clinical recommendation regarding the efficacy of amitriptyline for [Fibro] symptoms cannot be made. There is some evidence to support the short-term efficacy of amitriptyline 25 mg/day in FM. There is no evidence to support the efficacy of amitriptyline at higher doses or for periods [greater than] 8 weeks. "

The researchers went on to suggest that more stringent RCTs with follow-up periods are needed in order to determine the long-term efficacy and safety of amitriptyline and to define its role in the management of Fibro.

References:

1. Nishishinya B, Urrútia G, Walitt B, Rodriguez A, Bonfill X, Alegre C, Darko G. Amitriptyline in the treatment of fibromyalgia: a systematic review of its efficacy. Rheumatology (Oxford). 2008 Aug 12. [Epub ahead of print]