Lackey M N, Belknap E B, Greco D S, Fettman M J
Department of Clinical Sciences, Veterinary Teaching Hospital, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Am J Vet Res. 1996 Aug;57(8):1193-9.
To determine the pharmacokinetics of gentamicin sulfate in healthy llamas after i.v. administration of a single bolus and after repeated parenteral administration.
Prospective clinical trial.
19 clinically normal, adult male llamas for the single-dose trial and 10 of the 19 llamas for the multiple-dose trial.
In the first trial, llamas were given gentamicin (5 mg/kg of body weight, i.v.) as a single bolus, and serum gentamicin concentration was monitored over the next 48 hours. 2 months later, llamas were given gentamicin (2.5 mg/kg) i.v. for the first day, then IM every 8 hours for 7 days. Serum gentamicin concentration and indices of renal function and damage were monitored during the 7 days.
There were no significant dose- or time-related differences in clearance of the drug; volume of distribution; apparent coefficients of the distribution and elimination phases, alpha and beta, respectively; mean residence time; or distribution (t1/2 alpha) and elimination phase (t1/2 beta) half-lives. The 5 mg/kg i.v. kinetic study revealed t1/2 alpha of 14.5 +/- 5.06 minutes and t1/2 beta of 166 +/- 20.5 minutes. The 2.5 mg/kg i.v. kinetic study revealed t1/2 alpha of 17.7 +/- 6.59 minutes and t1/2 beta of 165 +/- 40.3 minutes. Peak serum gentamicin concentration averaged 10.10 micrograms/ml in the multiple-dose trial, and trough concentration averaged 1.50 micrograms/ml.
Dose effects were not observed for gentamicin clearance, volume of distribution, or half-lives. Multiple dosing at 2.5 mg/kg every 8 hours does not appear to cause renal impairment in healthy llamas.
Gentamicin pharmacokinetic variables in llamas appear to resemble those in other ruminant species.
确定硫酸庆大霉素在健康美洲驼静脉注射单剂量及多次肠胃外给药后的药代动力学。
前瞻性临床试验。
19只临床正常的成年雄性美洲驼用于单剂量试验，其中10只用于多剂量试验。
在首次试验中，给美洲驼静脉注射单剂量庆大霉素（5毫克/千克体重），并在接下来的48小时内监测血清庆大霉素浓度。2个月后，美洲驼第一天静脉注射庆大霉素（2.5毫克/千克），然后每8小时肌肉注射一次，共7天。在这7天内监测血清庆大霉素浓度以及肾功能和损伤指标。
药物清除率、分布容积、分布相和消除相的表观系数（分别为α和β）、平均驻留时间、分布半衰期（t1/2α）和消除相半衰期（t1/2β）在剂量或时间上均无显著差异。5毫克/千克静脉注射的动力学研究显示t1/2α为14.5±5.06分钟，t1/2β为166±20.5分钟。2.5毫克/千克静脉注射的动力学研究显示t1/2α为17.7±6.59分钟，t1/2β为165±40.3分钟。多剂量试验中血清庆大霉素峰值浓度平均为10.10微克/毫升，谷浓度平均为1.50微克/毫升。
未观察到庆大霉素清除率、分布容积或半衰期的剂量效应。每8小时2.5毫克/千克的多次给药似乎不会对健康美洲驼造成肾功能损害。
美洲驼的庆大霉素药代动力学变量似乎与其他反刍动物相似。
