Heather K. Knych, Daniel Weiner, Daniel S. McKemie, Megan Traynham, Jeff Blea
{"title":"Population pharmacokinetics of butorphanol following intramuscular administration to exercised thoroughbred horses","authors":"Heather K. Knych, Daniel Weiner, Daniel S. McKemie, Megan Traynham, Jeff Blea","doi":"10.1111/jvp.13450","DOIUrl":null,"url":null,"abstract":"<p>Butorphanol is commonly administered, both by the intravenous and intramuscular routes, to racehorses to facilitate handling for diagnostic procedures. As the administration of butorphanol for therapeutic purposes is considered appropriate, in order to avoid inadvertent positive drug tests, a thorough understanding of the pharmacokinetics of this drug is necessary. In the current study, 12, exercised Thoroughbred horses were administered a single intramuscular dose of 0.1 mg/kg butorphanol, and serum and urine samples were collected at various times post drug administration for determination of butorphanol concentrations using a highly sensitive liquid chromatography tandem mass spectrometry method. Serum data were modeled using a nonlinear mixed effect population PK model. The maximum concentration (<i>C</i>\n <sub>max</sub>) and time to maximum concentration (<i>T</i>\n <sub>max</sub>) were 139.9 ± 72.8 ng/mL and 0.43 ± 0.44 h (mean ± SD), respectively. Although likely not clinically relevant, but important for drug testing purposes, a prolonged terminal phase was observed, yielding a terminal half-life of 7.67 ± 1.86 h. Using the blood screening limits proposed by the Horseracing Integrity and Welfare Unit, the detection time for intramuscular administration of butorphanol was estimated to be 96 h.</p>","PeriodicalId":17596,"journal":{"name":"Journal of veterinary pharmacology and therapeutics","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvp.13450","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of veterinary pharmacology and therapeutics","FirstCategoryId":"97","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/jvp.13450","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHARMACOLOGY & PHARMACY","Score":null,"Total":0}
引用次数: 0
Abstract
Butorphanol is commonly administered, both by the intravenous and intramuscular routes, to racehorses to facilitate handling for diagnostic procedures. As the administration of butorphanol for therapeutic purposes is considered appropriate, in order to avoid inadvertent positive drug tests, a thorough understanding of the pharmacokinetics of this drug is necessary. In the current study, 12, exercised Thoroughbred horses were administered a single intramuscular dose of 0.1 mg/kg butorphanol, and serum and urine samples were collected at various times post drug administration for determination of butorphanol concentrations using a highly sensitive liquid chromatography tandem mass spectrometry method. Serum data were modeled using a nonlinear mixed effect population PK model. The maximum concentration (Cmax) and time to maximum concentration (Tmax) were 139.9 ± 72.8 ng/mL and 0.43 ± 0.44 h (mean ± SD), respectively. Although likely not clinically relevant, but important for drug testing purposes, a prolonged terminal phase was observed, yielding a terminal half-life of 7.67 ± 1.86 h. Using the blood screening limits proposed by the Horseracing Integrity and Welfare Unit, the detection time for intramuscular administration of butorphanol was estimated to be 96 h.
期刊介绍:
The Journal of Veterinary Pharmacology and Therapeutics (JVPT) is an international journal devoted to the publication of scientific papers in the basic and clinical aspects of veterinary pharmacology and toxicology, whether the study is in vitro, in vivo, ex vivo or in silico. The Journal is a forum for recent scientific information and developments in the discipline of veterinary pharmacology, including toxicology and therapeutics. Studies that are entirely in vitro will not be considered within the scope of JVPT unless the study has direct relevance to the use of the drug (including toxicants and feed additives) in veterinary species, or that it can be clearly demonstrated that a similar outcome would be expected in vivo. These studies should consider approved or widely used veterinary drugs and/or drugs with broad applicability to veterinary species.