Comparison of the sedative effects of medetomidine administered intranasally, by atomization or drops, and intramuscular injection in dogs

Majid Jafarbeglou; Mehdi Marjani

doi:10.1016/j.vaa.2019.05.003

Comparison of the sedative effects of medetomidine administered intranasally, by atomization or drops, and intramuscular injection in dogs

Vet Anaesth Analg. 2019 Nov;46(6):815-819. doi: 10.1016/j.vaa.2019.05.003. Epub 2019 Jun 8.

Authors

Majid Jafarbeglou¹, Mehdi Marjani²

Affiliations

¹ Department of Clinical Sciences, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran.
² Department of Clinical Sciences, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran. Electronic address: drmarjanivet@gmail.com.

PMID: 31416698
DOI: 10.1016/j.vaa.2019.05.003

Abstract

Objective: To compare the sedative effects of intranasal atomization (IN_A) of medetomidine with intranasal drops (IN_D) and intramuscular (IM) injection in healthy dogs.

Study design: Prospective, blinded, randomized study.

Animals: A group of 18 mixed-breed shelter-owned dogs weighing 27 ± 4.3 kg (mean ± standard deviation).

Methods: The dogs were randomly assigned to equal groups of six dogs for administration of medetomidine (40 μg kg^-1) by IN_A, IN_D and IM routes. Ease of administration was evaluated using a resistance scale. Composite sedation score (CSS), heart rate (HR) and respiratory frequency (f_R) were measured immediately before (T0, baseline) and after drug administration at time points 15, 45, 75 and 120 minutes. The time of onset of sedation was recorded. Ease of administration and onset of sedation were analysed by the Kruskal-Wallis and post hoc Dunn's tests. Repeated measures analysis of anova and least significant difference tests were used to analyse CSS, HR and f_R over time. Tukey's post hoc test was used for time point comparisons among groups. Significance was set at p < 0.05.

Results: No differences were detected among groups for ease of administration (p = 0.346). CSS increased in all groups from baseline values. Onset of sedation in IM was 6.3 ± 2.0 minutes, in IN_A was 7.2 ± 2.5 minutes and in IN_D was 20.7 ± 5.4 minutes. CSS in IN_D was lower than in the other groups at T15 and lower than in IN_A at T45. CSS was not different between IM and IN_A. HR and f_R decreased in all groups compared with respective baseline values. HR in IN_D was lower than in IM at T45-T120.

Conclusions and clinical relevance: IN_A medetomidine (40 μg kg^-1) can be an alternative and noninvasive route to IM injections for sedating healthy dogs. IN_D resulted in a slow onset of sedation.

Keywords: dog; intramuscular; intranasal administration; medetomidine; nasal atomizer; sedation.

Publication types

Randomized Controlled Trial, Veterinary

MeSH terms

Administration, Intranasal / veterinary
Aerosols / administration & dosage*
Animals
Dogs / physiology*
Female
Hypnotics and Sedatives / administration & dosage*
Hypnotics and Sedatives / pharmacology
Injections, Intramuscular / veterinary
Male
Medetomidine / administration & dosage*
Medetomidine / pharmacology

Substances

Aerosols
Hypnotics and Sedatives
Medetomidine