K N Grimsrud1, K R Mama, S M Thomasy, S D Stanley. 1. K.L. Maddy Equine Analytical Chemistry Laboratory, California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
Abstract
REASONS FOR PERFORMING STUDY: Detomidine is commonly used i.v. for sedation and analgesia in horses, but the pharmacokinetics and metabolism of this drug have not been well described. OBJECTIVES: To describe the pharmacokinetics of detomidine and its metabolites, 3-hydroxy-detomidine (OH-detomidine) and detomidine 3-carboxylic acid (COOH-detomidine), after i.v. and i.m. administration of a single dose to horses. METHODS: Eight horses were used in a balanced crossover design study. In Phase 1, 4 horses received a single dose of i.v. detomidine, administered 30 microg/kg bwt and 4 a single dose i.m. 30 microg/kg bwt. In Phase 2, treatments were reversed. Plasma detomidine, OH-detomidine and COOH-detomidine were measured at predetermined time points using liquid chromatography-mass spectrometry. RESULTS: Following i.v. administration, detomidine was distributed rapidly and eliminated with a half-life (t1/2(el)) of approximately 30 min. Following i.m. administration, detomidine was distributed and eliminated with t1/2(el) of approximately one hour. Following, i.v. administration, detomidine clearance had a mean, median and range of 12.41, 11.66 and 10.10-18.37 ml/min/kg bwt, respectively. Detomidine had a volume of distribution with the mean, median and range for i.v. administration of 470, 478 and 215-687 ml/kg bwt, respectively. OH-detomidine was detected sooner than COOH-detomidine; however, COOH-detomidine had a much greater area under the curve. CONCLUSIONS AND POTENTIAL RELEVANCE: These pharmacokinetic parameters provide information necessary for determination of peak plasma concentrations and clearance of detomidine in mature horses. The results suggest that, when a longer duration of plasma concentration is warranted, the i.m. route should be considered.
REASONS FOR PERFORMING STUDY: Detomidine is commonly used i.v. for sedation and analgesia in horses, but the pharmacokinetics and metabolism of this drug have not been well described. OBJECTIVES: To describe the pharmacokinetics of detomidine and its metabolites, 3-hydroxy-detomidine (OH-detomidine) and detomidine 3-carboxylic acid (COOH-detomidine), after i.v. and i.m. administration of a single dose to horses. METHODS: Eight horses were used in a balanced crossover design study. In Phase 1, 4 horses received a single dose of i.v. detomidine, administered 30 microg/kg bwt and 4 a single dose i.m. 30 microg/kg bwt. In Phase 2, treatments were reversed. Plasma detomidine, OH-detomidine and COOH-detomidine were measured at predetermined time points using liquid chromatography-mass spectrometry. RESULTS: Following i.v. administration, detomidine was distributed rapidly and eliminated with a half-life (t1/2(el)) of approximately 30 min. Following i.m. administration, detomidine was distributed and eliminated with t1/2(el) of approximately one hour. Following, i.v. administration, detomidine clearance had a mean, median and range of 12.41, 11.66 and 10.10-18.37 ml/min/kg bwt, respectively. Detomidine had a volume of distribution with the mean, median and range for i.v. administration of 470, 478 and 215-687 ml/kg bwt, respectively. OH-detomidine was detected sooner than COOH-detomidine; however, COOH-detomidine had a much greater area under the curve. CONCLUSIONS AND POTENTIAL RELEVANCE: These pharmacokinetic parameters provide information necessary for determination of peak plasma concentrations and clearance of detomidine in mature horses. The results suggest that, when a longer duration of plasma concentration is warranted, the i.m. route should be considered.
Authors: K N Grimsrud; S Ait-Oudhia; B P Durbin-Johnson; D M Rocke; K R Mama; M L Rezende; S D Stanley; W J Jusko Journal: J Vet Pharmacol Ther Date: 2014-07-29 Impact factor: 1.786
Authors: Vanessa Rabbogliatti; Martina Amari; Federica Alessandra Brioschi; Federica Di Cesare; Davide Danilo Zani; Donatella De Zani; Mauro Di Giancamillo; Petra Cagnardi; Giuliano Ravasio Journal: BMC Vet Res Date: 2022-07-11 Impact factor: 2.792
Authors: Noemi Romagnoli; Khaled M Al-Qudah; Sara Armorini; Carlotta Lambertini; Anna Zaghini; Alessandro Spadari; Paola Roncada Journal: Vet Med Sci Date: 2017-07-20