PARAMETRIC EVALUATION OF DEXMEDETOMIDINE IN DOGS PREMEDICATED OR NOT WITH ATROPINE AND TREATED OR NOT WITH KETAMINE.

E. HATSCHBACH, F. MASSONE, J. N. BECHARA, J. C. C. BALIEIRO, R. H. BARREIRO

Abstract


Dexmedetomidine is an alpha2 agonist drug widely used in men for pharmacologic side effect-free restraint. In this study, the first group (GI) was given intravenous dexmedetomidine (3 ìg/kg) during the induction and 3 ìg/kg diluted in distilled water to a volume of 20 mL over one hour using a syringe pump (fraction method). In the second group (GII), the same dose was used, but atropine (0.04mg/kg) was given subcutaneously 15 minutes before. The third group (GIII) received the same treatment of GII, but included ketamine (2mg/kg) in the same infusion. Each group included 10 healthy dogs, males or females, with body weight between 10 and 15 kg. We recorded not only the pharmacologic restraint, but 23 also the possible parasympathetic effects or either negative or positive synergism. We evaluated the latent, prostration and recovery periods, as well as the respiratory, oximetric and capnometric parameters. A profile analysis was performed in accordance with Morrison et al. (1967). Results showed bradiarrhythmia in GI, whereas the animals pretreated with atropine (GII) did not experience such effect. In GIII, dexmedetomidine was not enough to antagonize the cataleptic effects of ketamine. We concluded that dogs are well-restrained with dexmedetomidine at the dose of 3 ìg/kg and pretreatment of atropine. However, dexmedetomidine as a central-acting myorelaxant drug does not antagonize the undesired effects of ketamine.
KEY WORDS: Dog. Dexmedetomidine. Ketamine. Atropine.



DOI: http://dx.doi.org/10.15361/2175-0106.2005v21n1p22-29