Effects of tenoxicam on nociceptive thalamic neuronal firing in arthritic rats

The antinociceptive action of tenoxicam, a new non-steroidal anti-inflammatory drug, has been investigated by exploring the spontaneous and evoked electrophysiological patterns of firing of thalamic neurons in arthritic rats. A marked decrease in the firing activity evoked by ankle mobilization has been found to be present at doses of tenoxicam of 0.6 mg/kg i.v. A similar effect is obtainable with aspirin (as reference drug) but with doses of 54 mg/kg i.v. On studying the effects of increasing doses of tenoxicam a progressively longer time-course inhibition has been found and the analysis confirmed a linear correlation. Findings are discussed postulating that the final antinociceptive effect of tenoxicam can be correlated with its anti-inflammatory activity.