Effect of riluzole on acute pain and hyperalgesia in humans

Riluzole modulates several transmitter systems which may be involved innociception. Antinociceptive effects have been shown in animal studies, butthere are no human data. Therefore, we have examined the acute analgesiceffect of riluzole in a human model of inflammatory pain induced by athermal injury on the distal leg (47 degrees C, 7 min, 12.5 cm2) in 20healthy volunteers. Hyperalgesia to mechanical and heat stimuli wereexamined by von Frey hairs and thermodes. We used a randomized,double-blind, placebo-controlled design, and subjects received riluzole 100mg or placebo for 2 days with a 14-day interval. The burns producedsignificant hyperalgesia, but riluzole had no acute analgesic effects innormal or hyperalgesic skin.