Effect of yohimbine on detomidine induced changes in behavior, cardiac and blood parameters in the horse.
Abstract: To describe selected pharmacodynamic effects of detomidine and yohimbine when administered alone and in sequence. Methods: Randomized crossover design. Methods: Nine healthy adult horses aged 9 ± 4 years and weighing 561 ± 56 kg. Methods: Three dose regimens were employed in the current study. 1) 0.03 mg kg(-1) detomidine IV, 2) 0.2 mg kg(-1) yohimbine IV and 3) 0.03 mg kg(-1) detomidine IV followed 15 minutes later by 0.2 mg kg(-1) yohimbine IV. Each horse received all three treatments with a minimum of 1 week between treatments. Blood samples were obtained and plasma analyzed for detomidine and yohimbine concentrations by liquid chromatography-mass spectrometry. Behavioral effects, heart rate and rhythm, glucose, packed cell volume and plasma proteins were monitored. Results: Yohimbine rapidly reversed the sedative effects of detomidine in the horse. Additionally, yohimbine effectively returned heart rate and the percent of atrio-ventricular conduction disturbances to pre-detomidine values when administered 15 minutes post-detomidine administration. Plasma glucose was significantly increased following detomidine administration. The detomidine induced hyperglycemia was effectively reduced by yohimbine administration. Effects on packed cell volume and plasma proteins were variable. Conclusions: Intravenous administration of yohimbine effectively reversed detomidine induced sedation, bradycardia, atrio-ventricular heart block and hyperglycemia.
© 2012 The Authors. Veterinary Anaesthesia and Analgesia. © 2012 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists.
Publication Date: 2012-10-06 PubMed ID: 23035904DOI: 10.1111/j.1467-2995.2012.00776.xGoogle Scholar: Lookup
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- Journal Article
- Randomized Controlled Trial
Summary
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The study examined the effects of yohimbine in countering the effects of detomidine on heart function and blood parameters in horses. The researchers found that the administration of yohimbine quickly reversed the sedative effects, heart rate alterations, and hyperglycemia prompted by detomidine.
Research Design and Methods
- The study adopted a randomized crossover design featuring nine healthy adult horses aged 9 ± 4 years and weighing 561 ± 56 kg.
- The researchers utilized three dosage regimens for the study: a sole administration of detomidine, sole administration of yohimbine, and a sequential system of detomidine followed by yohimbine 15 minutes later. Each horse underwent all three treatments with a break of at least a week between each regimen.
- Blood samples were collected, and plasma was analyzed to gauge concentrations of both detomidine and yohimbine using liquid chromatography-mass spectrometry.
- The researchers closely monitored behavioral effects, heart rate and rhythm, glucose levels, packed cell volume, and plasma proteins.
Results
- The results illustrated that yohimbine quickly negated detomidine’s sedative effects in horses.
- Yohimbine was effective in restoring heart rate and the proportion of atrio-ventricular conduction abnormalities to pre-detomidine levels when administered 15 minutes after detomidine injection.
- There was a significant increase in plasma glucose following the administration of detomidine. However, the induced hyperglycemia was effectively reduced when yohimbine was administered after detomidine
- The effects on packed cell volume and plasma proteins varied, indicating these may be less consistently influenced by these agents.
Conclusions
- In conclusion, the intravenous administration of yohimbine demonstrated effectiveness in reversing the sedation, bradycardia (slowing of heart rate), atrio-ventricular heart block (a delay in conduction between the atria and ventricles of the heart) and hyperglycemia induced by detomidine in horses.
Cite This Article
APA
DiMaio Knych HK, Covarrubias V, Steffey EP.
(2012).
Effect of yohimbine on detomidine induced changes in behavior, cardiac and blood parameters in the horse.
Vet Anaesth Analg, 39(6), 574-583.
https://doi.org/10.1111/j.1467-2995.2012.00776.x Publication
Researcher Affiliations
- K.L. Maddy Equine Analytical Chemistry Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. hkknych@ucdavis.edu
MeSH Terms
- Adrenergic alpha-2 Receptor Antagonists / pharmacokinetics
- Adrenergic alpha-2 Receptor Antagonists / pharmacology
- Animals
- Behavior, Animal / drug effects
- Cross-Over Studies
- Dose-Response Relationship, Drug
- Drug Interactions
- Heart Rate / drug effects
- Horses / blood
- Horses / physiology
- Hypnotics and Sedatives / pharmacokinetics
- Hypnotics and Sedatives / pharmacology
- Imidazoles / administration & dosage
- Imidazoles / pharmacokinetics
- Imidazoles / pharmacology
- Yohimbine / administration & dosage
- Yohimbine / pharmacokinetics
Citations
This article has been cited 1 times.- Pakkanen SAE, de Vries A, Raekallio MR, Mykkänen AK, Palviainen MJ, Sankari SM, Vainio OM. Changes in energy metabolism, and levels of stress-related hormones and electrolytes in horses after intravenous administration of romifidine and the peripheral α-2 adrenoceptor antagonist vatinoxan.. Acta Vet Scand 2018 May 9;60(1):27.
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