According to the findings of a meta-analysis of clinical trial reports, pregabalin (Lyrica®) is effective in the treatment of certain patients with fibromyalgia (FM).

Researchers studied data from five randomised trials (total n=3,808) of pregabalin in FM, using the company trial reports supplied by Pfizer (these provide more detailed information than published papers). A PubMed literature search revealed no additional randomised controlled trials.  Data from four trials with standard design (double-blind, placebo-controlled) were pooled for meta-analysis (intention-to-treat).

All participants were adults and met the ACR criteria for FM, with pain scores of ≥40mm on the 100mm visual analogue scale (VAS) after stopping any relevant pain or sleep medication.  In the four standard trials, patients were randomised to receive oral gabapentin at a dose of 150-600mg/day or placebo under double-blind conditions, for 8-14 weeks.

In the pooled analysis, pregabalin at doses of 300–600 mg/day was found to increase the number of 30% responders and 50% responders.  The NNTs for one person to benefit compared with placebo over the dose range 300–600 mg/day of pregabalin were 9–14 for 300mg, 7–10 for 450mg and 8–11 for 600mg.  At least 50% pain relief was obtained by only 24% of the people taking pregabalin at the higher 450 and 600 mg doses. But, the investigators say, "While applicable only to a minority, this is an important outcome for those people who achieve it."  The rate of serious adverse events was similar for pregabalin and placebo.  

The authors conclude that the size of pregabalin’s therapeutic effect is “similar to that with other recent interventions such as duloxetine and the combination of tramadol and paracetamol.”