The local antinociceptive effects of paracetamol in neuropathic pain are mediated by cannabinoid receptors

Paracetamol analgesic mechanism of action is still poorly defined but mainly involves central inhibition of cyclooxygenases. Here we tested the peripheral antinociceptive effects of paraceramol (intraplantar injections) in a rat model of neuropathic pain. Paracetamol dose-dependently decreased mechanical allodynia and lowered nociceptive scores associated with hyperalgesia testing. These effects were inhibited by the administration of cannabinoid CB1 (AM251) and CB2 (AM630) receptor antagonists. The participation of the peripheral cannabinoid system in paracetamol analgesia is suggested. (c) 2007 Elsevier B.V. All rights reserved.