GABAPENTIN, INEFFECTIVE IN NORMAL RATS, MARKEDLY REDUCES C-FIBER EVOKED-RESPONSES AFTER INFLAMMATION

GABAPENTIN (Neurontin) is a novel anticonvulsant with an as yet unknow n mechanism of action. This electrophysiological study investigated th e potential antinociceptive actions of systemically administered gabap entin in normal animals and after inflammation induced by the injectio n of carrageenan. Gabapentin facilitated the noxious evoked responses of dorsal horn neurones recorded in normal animals. In complete contra st, gabapentin strongly and dose-dependently inhibited the C-fibre evo ked response and postdischarge, but not the Ap-fibre evoked response, of neurones recorded in animals 3 h after the injection of carrageenan . This unique and selective profile of gabapentin may provide a novel treatment for clinical inflammatory pain states.