Arguedas M G, Hines M T, Papich M G, Farnsworth K D, Sellon D C
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA.
J Vet Intern Med. 2008 Nov-Dec;22(6):1417-26. doi: 10.1111/j.1939-1676.2008.0200.x. Epub 2008 Oct 3.
Despite frequent clinical use, information about the pharmacokinetics (PK), clinical effects, and safety of butorphanol in foals is not available.
The purpose of this study was to determine the PK of butorphanol in neonatal foals after IV and IM administration; to determine whether administration of butorphanol results in physiologic or behavioral changes in neonatal foals; and to describe adverse effects associated with its use in neonatal foals.
Six healthy mixed breed pony foals between 3 and 12 days of age were used.
In a 3-way crossover design, foals received butorphanol (IV and IM, at 0.05 mg/kg) and IV saline (control group). Butorphanol concentrations were determined by high-performance liquid chromatography and analyzed using a noncompartmental PK model. Physiologic data were obtained at specified intervals after drug administration. Pedometers were used to evaluate locomotor activity. Behavioral data were obtained using a 2-hour real-time video recording.
The terminal half-life of butorphanol was 2.1 hours and C0 was 33.2 +/- 12.1 ng/mL after IV injection. For IM injection, Cmax and Tmax were 20.1 +/- 3.5 ng/mL and 5.9 +/- 2.1 minutes, respectively. Bioavailability was 66.1 +/- 11.9%. There were minimal effects on vital signs. Foals that received butorphanol spent significantly more time nursing than control foals and appeared sedated.
The disposition of butorphanol in neonatal foals differs from that in adult horses. The main behavioral effects after butorphanol administration to neonatal foals were sedation and increased feeding behavior.
尽管布托啡诺在临床上经常使用，但关于其在幼驹体内的药代动力学（PK）、临床效果和安全性的信息却并不存在。
本研究的目的是确定静脉注射（IV）和肌肉注射（IM）后布托啡诺在新生幼驹体内的药代动力学；确定布托啡诺的给药是否会导致新生幼驹出现生理或行为变化；并描述其在新生幼驹使用中相关的不良反应。
使用了6匹3至12日龄的健康杂种小马驹。
采用三交叉设计，幼驹接受布托啡诺（静脉注射和肌肉注射，剂量为0.05mg/kg）和静脉注射生理盐水（对照组）。通过高效液相色谱法测定布托啡诺浓度，并使用非房室药代动力学模型进行分析。给药后在特定时间间隔获取生理数据。使用计步器评估运动活动。通过2小时实时视频记录获取行为数据。
静脉注射后布托啡诺的末端半衰期为2.1小时，C0为33.2±12.1ng/mL。肌肉注射时，Cmax和Tmax分别为20.1±3.5ng/mL和5.9±2.1分钟。生物利用度为66.1±11.9%。对生命体征的影响极小。接受布托啡诺的幼驹比对照幼驹花费更多时间哺乳，且显得镇静。
布托啡诺在新生幼驹体内的处置与成年马不同。给新生幼驹注射布托啡诺后的主要行为影响是镇静和进食行为增加。
