Cardiovascular and sedation reversal effects of intramuscular administration of atipamezole in dogs treated with medetomidine hydrochloride with or without the peripheral alpha(2)-adrenoceptor antagonist vatinoxan hydrochloride - UTU Research Portal

A1 Refereed original research article in a scientific journal

Cardiovascular and sedation reversal effects of intramuscular administration of atipamezole in dogs treated with medetomidine hydrochloride with or without the peripheral alpha(2)-adrenoceptor antagonist vatinoxan hydrochloride

Authors: Turunen H, Raekallio MR, Honkavaara JM, Restitutti F, Kallio-Kujala IJ, Adam M, Nevanperä K, Scheinin M, Männikkö SK, Hautajärvi HJ, Menzies PL, Vainio OM

Publisher: AMER VETERINARY MEDICAL ASSOC

Publication year: 2019

Journal: American Journal of Veterinary Research

Journal name in source: AMERICAN JOURNAL OF VETERINARY RESEARCH

Journal acronym: AM J VET RES

Volume: 80

Issue: 10

First page : 912

Last page: 922

Number of pages: 11

ISSN: 0002-9645

eISSN: 1943-5681

DOI: https://doi.org/10.2460/ajvr.80.10.912

Abstract

OBJECTIVETo investigate the cardiovascular and sedation reversal effects of IM administration of atipamezole (AA) in dogs treated with medetomidine hydrochloride (MED) or MED and vatinoxan (MK-467).ANIMALS8 purpose-bred, 2-year-old Beagles.PROCEDURESA randomized, blinded, crossover study was performed in which each dog received 2 IM treatments at a >= 2-week interval as follows: injection of MED (20 mu g/kg) or MED mixed with 400 mu g of vatinoxan/kg (MEDVAT) 30 minutes before AA (100 mu g/kg). Sedation score, heart rate, mean arterial and central venous blood pressures, and cardiac output were recorded before and at various time points (up to 90 minutes) after AA. Cardiac and systemic vascular resistance indices were calculated. Venous blood samples were collected at intervals until 210 minutes after AA for drug concentration analysis.RESULTSHeart rate following MED administration was lower, compared with findings after MEDVAT administration, prior to and at >= 10 minutes after AA. Mean arterial blood pressure was lower with MEDVAT than with MED at 5 minutes after AA, when its nadir was detected. Overall, cardiac index was higher and systemic vascular resistance index lower, indicating better cardiovascular function, in MEDVAT-atipamezole-treated dogs. Plasma dexmedetomidine concentrations were lower and recoveries from sedation were faster and more complete after MEDVAT treatment with AA than after MED treatment with AA.CONCLUSIONS AND CLINICAL RELEVANCEAtipamezole failed to restore heart rate and cardiac index in medetomidine-sedated dogs, and relapses into sedation were observed. Coadministration of vatinoxan with MED helped to maintain hemodynamic function and hastened the recovery from sedation after AA in dogs.