The NSAID dexketoprofen trometamol is as potent as mu-opioids in the depression of wind-up and spinal cord nociceptive reflexes in normal rats

The aim of this study was to examine the potency of the antinociceptive eff ects of the non-steroidal antiinflammatory drug (NSAID), Dexketoprofen Trom etamol (the active enantiomer of ketoprofen) on spinal cord nociceptive ref lexes. These effects were compared with those of the mu-opioid receptor ago nist fentanyl in normal animals. The experiments were performed in male Wis tar rats anaesthetised with alpha-chloralose. The nociceptive reflexes were recorded as single motor units in peripheral muscles,activated by mechanic al and electrical stimulation. Both dexketoprofen and fentanyl inhibited re sponses evoked by mechanical and electrical stimulation with doses in the s ame nanomolar range (dexketoprofen ID50s: 100 and 762 nmol kg(-1) and fenta nyl: 40 and 51 nmol kg(-1), respectively). Dexketoprofen and fentanyl also significantly inhibited wind-up. Since fentanyl has been shown to be some 1 000 times more potent than morphine in this type of experiments, we conclud e that dexketoprofen has central analgesic actions in normal animals and de presses nociceptive responses with a potency similar to that of mu-opioid a gonists. (C) 1999 Elsevier Science B.V. All rights reserved.