Gabapentin and pregabalin in the treatment of fibromyalgia: a systematic review
and a meta-analysis.
Author(s): Tzellos TG, Toulis KA, Goulis DG, Papazisis G, Zampeli VA, Vakfari A, Kouvelas D.
Affiliation(s): Department of Pharmacology, School of Medicine, Aristotle University of
Publication date & source: 2010, J Clin Pharm Ther. , 35(6):639-56
WHAT IS KNOWN AND OBJECTIVES: Fibromyalgia (FBM) is a common chronic pain
disorder affecting up to 2% of the general population. Current treatment options
are mostly symptom-based and limited both in efficacy and number. Two promising
alternatives are gabapentin (GP) and pregabalin (PB). We aimed to estimate the
efficacy and safety/tolerability of the two compounds in FBM through a systematic
review and a meta-analysis of relevant randomized double-blind placebo-controlled
(RCT) were performed. DATA SOURCES, EXTRACTION AND ANALYSIS: A literature search
was conducted through MEDLINE, EMBASE, Cochrane CENTRAL and the reference lists
of relevant studies. Responders to treatment (>30% reduction in mean pain score)
and dropouts due to lack of efficacy were used as primary outcome measures.
Dropout rates and incidence of common adverse outcomes were also investigated.
Four RCTs, reporting data on 2040 patients, were reviewed and three of them using
PG were included in the meta-analysis. RESULTS: Pregabalin at a dose of 600, 450
and 300 mg per day is effective in FBM compared to placebo (NNT: 7, upper 95% CI:
12, 450 mg). A number of adverse events (AE), such as dizziness, somnolence, dry
mouth, weight gain, peripheral oedema, is consistently associated with treatment
at any dose and could lead one out of four patients to quit treatment (NNH: 6,
lower 95% CI: 4, 600 mg). Indirect comparison meta-analysis suggests that PB at a
dose of 450 mg per day could result in more responders than at 300 mg, but this
result needs to be interpreted with caution as there were no significant
differences between 600 and 300 mg or between 600 and 450 mg. Data on GP is
limited. WHAT IS NEW AND CONCLUSIONS: The analysis indicates that PB at a dose of
450 mg per day is most likely effective in treating FBM, although AE are not
negligible. Further evidence is necessary for more conclusive inferences.