Modulation of NSAID-induced antinociceptive and anti-inflammatory effects by alpha2-adrenoceptor agonists with gastroprotective effects

Life Sci. 2002 May 3;70(24):2857-69. doi: 10.1016/s0024-3205(02)01549-7.

Abstract

Tizanidine, an alpha2-adrenergic receptor agonist with myospasmolytic action, is indicated for the treatment of back pain either as monotherapy or in combination with nonsteridal anti-inflammatory drugs (NSAIDs). Tizanidine (0.25-1.0 mg/kg) significantly produced analgesic and anti-inflammatory effect in acetic acid induced writhing in mice and carrageenan-induced paw edema in rats, respectively. The effects were comparable with clonidine (0.25 and 0.50 mg/kg), another alpha2-agonist. Yohimbine (1 mg/kg), alpha2-adrenergic antagonist reversed the effect of tizanidine. Tizanidine (0.25 mg/kg) and clonidine (0.25 mg/kg) significantly potentiated the antinociceptive and anti-inflammatory effect of NSAIDs (nimesulide, meloxicam and naproxen). Tizanidine (1 mg/kg) did not alter basal pH, acidity (free and total) of gastric content and did not produce any mucosal injury in fasted rats. Tizanidine (1 mg/kg) significantly reduced meloxicam (UD50 3.21 mg/kg), nimesulide (UD50 24.52 mg/kg) and naproxen (UD50 14.10 mg/kg)-induced ulcerogenic effect (ulcer index, pH and free/total acidity). It is expected that tizanidine exerted gastrotprotection through stimulation of gastric and central alpha2-adrenergic receptors. Present investigation suggested that tizanidine not only enhance the analgesic and anti-inflammatory effect of NSAIDs but also improved gatstrointestinal tolerability of NSAIDs through modulation of central alpha-2-receptors. From this study, it can be speculated that tizanidine and NSAID combination therapy would prove to be a novel approach to treat nociceptive/inflammatory conditions with improved gastric tolerability of NSAIDs.

Publication types

  • Comparative Study

MeSH terms

  • Adrenergic alpha-Agonists / therapeutic use*
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Clonidine / analogs & derivatives*
  • Clonidine / therapeutic use
  • Drug Synergism
  • Drug Therapy, Combination
  • Meloxicam
  • Mice
  • Naproxen / therapeutic use
  • Pain / drug therapy*
  • Rats
  • Rats, Wistar
  • Receptors, Adrenergic, alpha-2 / metabolism*
  • Stomach Ulcer / prevention & control*
  • Sulfonamides / therapeutic use
  • Thiazines / therapeutic use
  • Thiazoles / therapeutic use
  • Yohimbine / therapeutic use

Substances

  • Adrenergic alpha-Agonists
  • Anti-Inflammatory Agents, Non-Steroidal
  • Receptors, Adrenergic, alpha-2
  • Sulfonamides
  • Thiazines
  • Thiazoles
  • Yohimbine
  • Naproxen
  • tizanidine
  • Clonidine
  • nimesulide
  • Meloxicam