Gabapentin for neuropathic pain: systematic review of controlled and uncontrolled literature.
OBJECTIVE
To assess the efficacy/effectiveness and side effects of gabapentin for the treatment of neuropathic pain.


METHODS
Systematic review of the literature.


METHODS
Extensive search of several electronic databases located both controlled and uncontrolled studies. Efficacy was assessed through meta-analysis of randomized controlled trials (RCTs), whereas the effectiveness of gabapentin in uncontrolled studies was assessed via a novel system of dichotomous classification of "bad" versus "good" results.


RESULTS
Thirty-five papers involving 727 patients with multiple neuropathic pain conditions met the inclusion criteria. The meta-analysis of the 2 high-quality, placebo-controlled RCTs showed positive effect of gabapentin in diabetic neuropathy and post-herpetic neuralgia. The addition of 2 low-quality, placebo-controlled RCTs did not alter the magnitude or direction of observed effect. The uncontrolled studies demonstrated positive effect on pain in different neuropathic syndromes, as well as benefit on different types of neuropathic pain; highest dose administered and rate-of-dose escalation showed wide variability between prescribers. Fewer and less severe side effects were reported in the uncontrolled studies.


CONCLUSIONS
Gabapentin seems to be effective in multiple painful neuropathic conditions. The variable prescribing patterns of the uncontrolled studies raise the suspicion that effectiveness may be reduced if one limits administration of the drug to very low doses, whereas rapid dose escalation may be associated with increased central nervous system side effects. Well-designed controlled trials may provide insight into differential symptom sensitivity to the drug.
Mellegers
M A
MA
University of Maastricht, The Netherlands.
Furlan
A D
AD
Mailis
A
A
D000085:Acetates / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000588:Amines; D000700:Analgesics / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D003509:Cyclohexanecarboxylic Acids; D004305:Dose-Response Relationship, Drug; D000077206:Gabapentin; D006801:Humans; D009437:Neuralgia / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D005680:gamma-Aminobutyric Acid
D000085:Acetates; D000588:Amines; D000700:Analgesics; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin