Three combinations of clonidine in association with tiletamine-zolazepam for anaesthesia induction in rats: evaluation of reflexes and pain sensibility

Abstract

ABSTRACT:The aim of this study was to assess the combination of tiletamine-zolazepam (Zoletil 20 ® ) with three different doses of clonidine for general anaesthesia induction in rats submitted to vascular microsurgery. The evaluation of anaesthetic and analgesic effects was performed in 30 Wistar rats randomly divided into three groups and induced with Zoletil 20 [90 mg/kg Intraperitoneal (IP)] associated with three different doses of clonidine (60-90-120 μg/kg IP). Four clinical parameters were evaluated after induction: loss of righting reflex, voluntary movement, the pedal withdrawal response, and pain sensitivity tested by pinching the tail. The combination of Zoletil with 90 and 120 μg/kg of clonidine provided a surgical anaesthesia; however, 90 μg/kg of clonidine provided the most rapid anaesthesia induction, as confirmed by data obtained by clinical evaluation of the loss of the pedal withdrawal response and the absence of the tail pinch response. The increase in dose of clonidine did not lead to a more rapid action of the α2 agonist, probably due to achievement of a dose-dependent plateau.

Principles of therapy and care of laboratory animals after chronic administration into Xylasine-Zoletyl® Anesthesia

“…These measures are described for drugs such as acetaminophen, acetylsalicylic acid, butorphanol, codeine, fentanyl + medetomidine, ibuprofen, ketamine + xylazine, mepiridine, methadone, morphine, nalbufen, nalorphine, oxymorphine, phenobarbital / zolotophazine, tylepaxol and a number of others [6]. For a combination of drugs Zoletil ® (Zoletil20, 50 or 100) and XilaVet (Xila (xylazine)), measures that prevent the development of negative effects on the animal's body are insuffi ciently developed and described in the literature [7,8], although the action of a combination of dissociative anesthetics and alpha-2-agonists is detailed investigated in laboratory animals [9][10][11]. Xilazine is an alpha-2-adrenergic agonist, is a muscle relaxant and antihypertensive agent.…”