Study of analgesic effects and plasmatics concentrations of tramadol in female dogs submitted to ovaryhisterectomy / Estudo dos efeitos analgésicos e das concentrações plasmáticas do tramadol em cadelas submetidas a ovário-salpingo-histerectomia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The aim of this study was to use an analytic method to tramadol quantification in the plasma of female dogs submitted to ovaryhisterectomy, evaluate the plasmatic concentrations and its analgesic effect on these animals. First of all, there were made the ovaryhisterectomy surgeries and posterior pain evaluation in 12 female dogs divided in 2 groups of 6 animals, wich received 2 mg/kg of tramadol in a single dose, by intravenous or intramuscular route, with the in double blind administration. Then, it was implantation and standardization of the method to detect and quantify tramadol in dog′s plasma. For that, it was utilized the high performance liquid chromatography to determine tramadol′s concentration, being necessary the adaptation and validation of this method to our laboratorie′s conditions. The method′s validation considered the linearity study, the construction of calibration′s curve, the accuracy′s determination and the recovery of tramadol. According to the results, the method was considered suitable, because it presented linearity response in the desirable range. After the validation of the methodology, the evaluation of tramadol′s plasmatic concentrations in the female dogs started and were calculated the pharmacokinetics parameters. The results showed that the variation of tramadol′s concentrations was significantly affected by administration routes. The group that received tramadol by intravenous route presented area under curve the time zero until infinity (AUC0→ ∞) superior to the group treated by intramuscular route, showing that the tramadol administrated by intravenous route can have more biodisponibility of this drug in the animal′s body. Regarding the analgesic effect it was observed that the administration of 2 mg/kg of tramadol, by intravenous route, promoted analgesia with length between 1.50 to 2.00 h in 67% of the animals (4 female dogs), while the intramuscular route promoted analgesia until 6 h in 67% of the animals. In this study it was observed wide variations in the tramadol′s plasmatic concentrations. In the moment that the pain′s presence was viewed, tramadol′s plasmatic concentration varied around 300 to 600 ng/ml in 71.0% of the animals. For this reason, the high performance liquid chromatography with ultra violet detector presented suitable to evaluate tramadol′s plasmatic concentrations in female dogs submitted to ovaryhisterectomy and the administration route makes big influence on tramadol′s analgesic effect moreover, the administration by intramuscular route promoted analgesia with length bigger than the other one produced by intravenous route

ASSUNTO(S)

tramadol pain plasma female dog cromatografia dor cadelas plasma tramadol chromatography

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