Weisel M K, Powers J D, Powers T E, Baggot J D
Am J Vet Res. 1977 Feb;38(2):273-5.
Studies were conducted to determine certain kinetic variables for tylosin in the normal dog. These variables were determined by pharmacokinetic analysis, measuring the decrease in serum concentration of tylosin activity in 3 separate experiments. Tylosin, given as a single intravenous dose of 10 mg of tylosin activity/kg of body weight, was calculated to have an elimination half life (t1/2beta) of 54 minutes and was no longer detectable in the serum by assay methods at about 270 minutes. In addition, tylosin appeared to be highly distributed with an apparent volume of distribution of about 1.7 L/kg and a tissue-to-plasma ratio of about 0.7. The body clearance of tylosin was calculated to be about 22 ml/kg minute. A separate multiple-dose intravenous experiment with the same dose per injection was conducted and showed similar results. Also, single intramuscular injection of 10 mg of tylosin activity/kg showed tylosin to peak after injection in the serum at 30 minutes, attaining a concentration of approximately 1.5 mug/ml. This concentration was maintained through 60 minutes and decreased slowly through 540 minutes. Data generated through 17 clinical cases indicated that the minimum inhibitory concentration for tylosin in Pasteurella spp tested was about 6.25 mcs/ml and for hemolytic Staphylococcus spp tested greater than or equal to 0.4 mug/ml. Thus, it would appear that tylosin, given at the recommended dose (6.6 to 11.0 mg tylosin activity/kg of body weight once or twice per day), would produce serum levels insufficient to treat all Pasteurella spp and some hemolytic Staphylococcus spp tested since a serum level of tylosin at slightly higher than 1 mug/ml for about 30 minutes was achieved in this study.
开展了多项研究以确定泰乐菌素在正常犬体内的某些动力学变量。这些变量通过药代动力学分析来确定，在3个独立实验中测量泰乐菌素活性的血清浓度下降情况。以10mg泰乐菌素活性/kg体重的单次静脉注射剂量给药后，计算得出泰乐菌素的消除半衰期（t1/2β）为54分钟，约270分钟后通过检测方法在血清中不再可检测到。此外，泰乐菌素似乎分布广泛，表观分布容积约为1.7L/kg，组织与血浆的比率约为0.7。泰乐菌素的机体清除率经计算约为22ml/kg·分钟。进行了一次单独的多剂量静脉注射实验，每次注射剂量相同，结果相似。同样，单次肌肉注射10mg泰乐菌素活性/kg后，血清中的泰乐菌素在注射后30分钟达到峰值，浓度约为1.5μg/ml。该浓度在60分钟内保持稳定，并在540分钟内缓慢下降。通过17例临床病例得出的数据表明，所检测的巴斯德氏菌属中泰乐菌素的最低抑菌浓度约为6.25μg/ml，所检测的溶血性葡萄球菌属中泰乐菌素的最低抑菌浓度大于或等于0.4μg/ml。因此，似乎按照推荐剂量（6.6至11.0mg泰乐菌素活性/kg体重，每天一次或两次）给药时，泰乐菌素产生的血清水平不足以治疗所有所检测的巴斯德氏菌属和一些溶血性葡萄球菌属，因为在本研究中，泰乐菌素的血清水平略高于1μg/ml约30分钟。
