Pharmacokinetics and pharmacodynamics of intravenous medetomidine in the horse

摘要: Abstract Objective To describe the pharmacodynamics and pharmacokinetics following an intravenous (IV) bolus dose of medetomidine in horse. Study design Prospective experimental trial. Animals Eight, mature healthy horses age 11.7 ± 4.6 (mean SD) years, weighing 557 54 kg. Methods Medetomidine (10 μg kg −1 ) was administered IV. Blood sampled at fixed time points from before drug administration to 48 hours post administration. Behavioral, physiological biochemical data were obtained predetermined 0 minutes 24 An algometer also used measure threshold responses noxious stimuli. concentrations determined by liquid chromatography-Mass Spectrometry for calculation pharmacokinetic parameters using noncompartmental compartmental analysis. Results Pharmacokinetic analysis estimated that peaked (8.86 3.87 ng mL 6.4 2.7 last detected 165 77 had a clearance 39.6 14.6 minute volume distribution 1854 565 . The elimination half-life 29.1 12.5 minutes. Glucose concentration reached maximum 176 46 mg dL approximately 1 hour Decreased heart rate, respiratory borborygmi, packed cell volume, total protein observed Horses lowered their heads 107 12 20 10 cm within gradually returned normal. Horse mobility decreased after increased mechanical present 45 less responsive sound. Conclusion clinical relevance  Behavioral effects positively correlate with profiles plasma concentrations. transiently analgesic effect appeared have very short duration.