Cephalosporin antimicrobials can be utilized for the treatment of sepsis in neonatal foals, particularly when an aminoglycoside is contraindicated. Some cephalosporins, however, are not utilized because of cost, sporadic availability, or uncertainty about efficacy. The plasma disposition of ceftazidime, a third-generation cephalosporin with a broad spectrum of activity against a wide variety of gram-negative bacteria and minimal renal side effects has not been reported in neonatal foals. In this study, the plasma disposition of single intravenous (IV) and intramuscular (IM) doses of ceftazidime in neonatal foals was determined. Six healthy one to two-day-old foals were given 25 mg/kg of ceftazidime by IV and IM routes in a cross-over design, with a 48-h washout period between doses. Non-compartmental analysis was used to estimate plasma pharmacokinetic parameters. Median t_1/2 was 2 h and median AUC_0-last was 364 µg h/ml for both IV and IM administration. Median C_max after IM administration was 101 µg/ml, with a median T_max of 0.7 h. Relative bioavailability of IM injection was 90%. There were no statistically significant differences between estimated IV and IM pharmacokinetic parameters. Plasma concentrations remained above the human CLSI susceptible breakpoint for Enterobacteriaceae for over 8 h following IV and IM administration.

中文翻译：

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静脉内和肌肉内给药后头孢他啶在健康新生儿马驹中的血浆分布

头孢菌素类抗菌剂可用于治疗新生儿马驹的败血症，尤其是在禁用氨基糖苷类药物时。然而，由于成本、零星供应或疗效不确定性，一些头孢菌素没有被使用。头孢他啶是一种第三代头孢菌素，对多种革兰氏阴性菌具有广谱活性，且肾脏副作用最小，尚未在新生儿马驹中报告其血浆处置情况。在这项研究中，测定了新生儿马驹中单次静脉内 (IV) 和肌肉内 (IM) 头孢他啶剂量的血浆处置。在交叉设计中，通过 IV 和 IM 途径给予 6 只健康的 1 至 2 日龄马驹 25 mg/kg 头孢他啶，剂量之间有 48 小时的冲洗期。非房室分析用于估计血浆药代动力学参数。中位数对于 IV 和 IM 给药，_1/2为 2 小时，中位 AUC _{0-last为 364 µg h/ml。}IM 给药后的中位 C _max为 101 µg/ml，中位 T _max为 0.7 h。IM 注射的相对生物利用度为 90%。估计的 IV 和 IM 药代动力学参数之间没有统计学上的显着差异。在 IV 和 IM 给药后 8 小时内，血浆浓度仍高于肠杆菌科的人类 CLSI 敏感折点。