A comparison of the antinociceptive effects of voltage-activated Na+ channel blockers in two rat models of neuropathic pain

Eur J Pharmacol. 2003 Jan 5;458(3):275-82. doi: 10.1016/s0014-2999(02)02792-9.

Abstract

The pain-relieving effects of various voltage-activated Na(+) channel blockers have been evaluated in two rat models of neuropathic pain; the photochemically induced nerve injury model (Gazelius) and spared nerve injury model. Lidocaine (up to 40 mg/kg, i.p.) and lamotrigine (up to 60 mg/kg, i.p.) had no effect on mechanical or cold allodynia in either model. However, lamotrigine (10, 30 and 60 mg/kg) significantly attenuated mechanical hyperalgesia in the spared nerve injury model, while mexiletine (25 and 37.5 mg/kg, i.p.) attenuated mechanical allodynia in the Gazelius model. Tocainide (50, 75 and 100 mg/kg, i.p.) significantly reduced all types of pain behaviour measured. The present results show that these voltage-activated Na(+) channel blockers have broadly similar antinociceptive effects in these two models of neuropathic pain. They also show that these drugs can have markedly different effects on distinct neuropathic pain-related behaviours within models.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics / pharmacology*
  • Analysis of Variance
  • Anesthetics, Local / pharmacology
  • Animals
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Hindlimb / drug effects
  • Hindlimb / injuries
  • Hindlimb / innervation
  • Lamotrigine
  • Lidocaine / pharmacology
  • Male
  • Mexiletine / pharmacology
  • Neuralgia / prevention & control*
  • Pain Measurement / methods
  • Rats
  • Rats, Sprague-Dawley
  • Sodium Channel Blockers / pharmacology*
  • Sodium Channels / drug effects
  • Time Factors
  • Tocainide / pharmacology
  • Triazines / pharmacology

Substances

  • Analgesics
  • Anesthetics, Local
  • Sodium Channel Blockers
  • Sodium Channels
  • Triazines
  • Mexiletine
  • Tocainide
  • Lidocaine
  • Lamotrigine