Riond J L, Riviere J E
Department of Anatomy, College of Veterinary Medicine, North Carolina State University, Raleigh 27606.
Am J Vet Res. 1990 Aug;51(8):1271-5.
The disposition of doxycycline hyclate after IV administration of 20 mg/kg of body weight was studied in 6 pigs. Median elimination half-life, estimated in 4 pigs, was 3.92 hours. Mean (+/- SEM) total body clearance was 1.67 +/- 0.18 ml/min/kg, and mean apparent volume of distribution at steady state was 0.53 +/- 0.04 L/kg. In 2 pigs, secondary peaks in the logarithmic serum concentration-time profile suggested discontinuous enterohepatic cycling, and precluded using these pigs in the pharmacokinetic analysis. The extent of doxycycline binding to serum protein was 93.1 +/- 0.2%. Serum or urine from 3 of the pigs was analyzed by use of photodiode array detection and mass spectrometry of a high-performance liquid chromatographic column effluent. These procedures documented lack of doxycycline biotransformation in pigs. It is concluded that, despite an elimination half-life shorter than that reported in other species, doxycycline may be a valuable antimicrobial drug for use in swine practice, pending the development of appropriate formulations.
在6头猪身上研究了静脉注射20mg/kg体重的盐酸多西环素后的处置情况。在4头猪中估计的中位消除半衰期为3.92小时。平均（±标准误）总体清除率为1.67±0.18ml/min/kg，稳态时平均表观分布容积为0.53±0.04L/kg。在2头猪中，对数血清浓度-时间曲线中的二次峰提示存在间断的肠肝循环，因此排除这2头猪进行药代动力学分析。多西环素与血清蛋白的结合程度为93.1±0.2%。使用光电二极管阵列检测和高效液相色谱柱流出物的质谱分析法对3头猪的血清或尿液进行了分析。这些方法证明猪体内不存在多西环素的生物转化。结论是，尽管消除半衰期比其他物种报道的要短，但在开发出合适的制剂之前，多西环素可能是猪临床实践中一种有价值的抗菌药物。
