[Analgesic actions after local peripheral administration of Lornoxicam in a model of formalin test in the rat].

Objective: To investigate analgesic actions after local peripheral administration of Lornoxicam in an animal model of formalin test.

Methods: Male Spague-Dawley rats were randomly divided into 3 groups, namely the control, the ipsilateral and the contralateral groups. Each group consisted of 8 rats. Thirty minutes prior to subcutaneous injections of 20 g/L formalin 50 microl into the plantar surface of the right hind-paw, the rats of ipsilateral group received Lornoxicam in the plantar surface of the right hind-paw, and the rats of contralateral group received Lornoxicam in the contralateral plantar surface of the hindpaw. Pain response was recorded for a period of 60 minutes. The summation of time (in seconds) spent in licking and biting responses to the injected paw during each 5 minutes block was analyzed for comparison.

Results: The pain response in the first phase (from 0 to 10 minutes) was not inhibited (P > 0.05). The pain response in the second phase (from 10 to 60 minutes) was inhibited in the ipsilateral group (P < 0.05).

Conclusion: Local peripheral administration of Lornoxicam has analgesic effect on the rat's planta in the second phase of a formalin test model; the mechanism involved is mainly local, but not systemic.