Review Effectiveness of pharmacological therapies for fibromyalgia syndrome in adults: an overview of Cochrane Reviews, Moore et al., 2024

Abstract
Objectives
To summarize and evaluate Cochrane reviews of pharmacological therapies for adults with fibromyalgia syndrome (FMS) pain.

Methods
Systematic search of Cochrane Database of Systematic Reviews to May 2024. Generic quality assessment used AMSTAR-2 criteria, validity checks of potentially critical factors in evaluation of analgesic efficacy and assessment of susceptibility of results to publication bias. Pain outcomes were participant-reported pain relief of ≥30% or ≥50%, or PGIC much or very much improved.

Results
Twenty-one reviews (87 trials, 17 631 patients) were included. All rated moderate (15) or high-quality (6) using AMSTAR-2 and at least seven of eight critical pain criteria were met by 13 of 21 reviews. Diagnosis of FMS used recognized criteria. Seven reviews found no trials (carbamazepine, clonazepam, lamotrigine, phenytoin, oxycodone, topiramate or valproate), seven had limited and inadequate data (antipsychotics, cannabinoids, combination therapy, gabapentin, lacosamide, monoamine oxidase inhibitors, NSAIDs) and two were subject to publication bias (amitriptyline, SSRI). Mirtazapine had moderate evidence of no effect. Duloxetine, milnacipran and pregabalin had moderate/good evidence of substantial pain relief for 4–12 weeks in around 1 in 10 adults with moderate or severe FMS pain, without evidence of efficacy beyond six months. Serious adverse events were no more common than with placebo. There was no evidence about who might benefit or experience adverse events. There was no substantial efficacy evidence for other medicines.

Conclusions
Duloxetine, milnacipran and pregabalin had good evidence that about 1 person in 10 with moderate or severe pain experienced pain intensity reduction by at least 50%.

Link: https://academic.oup.com/rheumatolo...1093/rheumatology/keae707/7929825?login=false

 

Relief in just 1 in 10 patients seems staggeringly low, but the tone of the paper doesn't seem to convey this.

 

I am sceptical that you can pick apart cohort data like that. You cannot ascribe efficacy in individual cases based on a statistical analysis of a cohort, surely?

It is quite a motley crowd of authors. The first author lives in Plymouth but we are told no more.

In my limited personal experience duloxetine produces very unpleasant dysphoric side-effects. It seems to be something of an orphan drug that was never much good for what it was intended for so gets used for anything untreatable on spec.

This seems a pretty peculiar paper because it isn't in itself a review but just a list of reviews already done that takes them at face value. It adds no information as far as I can see. Very likely the duloxetine review was less careful than the others.

 

He seems to have been a clinical biochemist in Oxford, and has a personal interest in pain research.