Subarachnoid meloxicam does not inhibit the mechanical hypernociception on carrageenan test in rats

Abstract

Background and objective: Evaluate the antinociceptive effects of subarachnoid meloxicam on the mechanical hypernociception induced by carrageenan in rats. Methods: Randomized controlled trial. Eighteen adult male Wistar rats underwent a cannula implantation into the subarachnoid space and were randomly divided into two groups: Group I received saline solution 5 L, while Group II received meloxicam 30 mg. The mechanical hypernociception was induced by intraplantar injection of carrageenan and evaluated using a digital analgesy meter every 30 min during a 4-h period. The results were recorded as the withdrawal threshold (in g), calculated by subtracting the measurement value after treatment from baseline. Results: The withdrawal threshold mean values were lower in the group of patients treated with meloxicam over all time points between 45 and 165 min, however, there was no statistical significance (p = 0.835) for this difference. Conclusion: Subarachnoid meloxicam at a dose of 30 g animal −1 did not suppress the mechanical hypernociception in a model of inflammatory pain induced by intraplantar administration of carrageenan in rats. The data suggest that other dosages should be investigated the drug effect is discarded. Evaluation of antinociceptive effects of subarachnoid meloxicam 125 PALAVRAS-CHAVE AINE; Carragenina; Dor; Medula espinhal Meloxicam subaracnoide não inibe a hipernocicepção mecânica no teste da carragenina em ratosResumo Justificativa e objetivo: avaliar os efeitos antinociceptivos do meloxicam subaracnóideo sobre a hipernocicepção mecânica induzida pela carragenina em ratos. Métodos: estudo randômico e controlado. Dezoito ratos Wistar, machos adultos, foram submetidos à implantação de uma cânula subaracnóidea, e aleatoriamente distribuídos em dois grupos: o Grupo I (GI) recebeu 5 L de solução salina, enquanto que ao Grupo II (GII) foram administrados 30 g de meloxicam, ambos pela via subaracnóidea. A hipernocicepção mecânica foi induzida pela injeção intraplantar de carragenina e avaliada com o emprego de um analgesímetro digital a cada 30 minutos durante um período de 4 horas. Os resultados foram registrados como o do limiar de retirada (g), calculado subtraindo-se o valor das mensurações após os tratamentos, do valor basal. Resultados: os valores médios do do limiar de retirada foram menores no grupo tratado com meloxicam ao longo de todos os momentos de avaliação entre 45 e 165 minutos, contudo não foi demonstrada significância estatística (p = 0,835) para essa diferença. Conclusão: a administração subaracnóidea do meloxicam na dose de 30 g.animal -1 não foi capaz de suprimir a hipernocicepção mecânica em um modelo de dor inflamatória induzida pela administração intraplantar de carragenina em ratos. Os dados sugerem que outras doses sejam pesquisadas antes que o efeito do fármaco seja descartado.

Systemic and neurotoxic effects of epidural meloxicam in rabbits

“…In recent years, the use of NSAIDS to promote analgesia by the spinal route has been extensively researched (ORLANDO, 2011). MOURA (2015) administered meloxicam in the subarachnoid space in rats at a dosage of 30 µg per animal and observed no systemic side effects or behavioral or neurological disorders in animals during the evaluation period. However, the experimental dose was insufficient to suppress induced hyperalgesia, suggesting the need for a larger dose to achieve the desired analgesic effect in the spinal cord, even though a larger dose could trigger neurotoxic effects.…”

“…One of the main advantages of the epidurally administered NSAID is the discreet action in the gastric, renal, and hepatic systems in addition to platelet aggregation and fewer obvious side effects (CANDUZ et al, 2006). However, it is necessary to evaluate the toxicity of any substance that will be in contact with the central nervous system, as each drug has different characteristics and promotes specific actions in the cell, which can undermine spinal cord surgery (MOURA, 2015).…”