Metronidazole (MTZ) is a 5-nitroimidazole anti-bacterial and anti-protozoal drug. In human and companion animal medicine, MTZ remains widely used due to its effectiveness against anaerobic bacteria and protozoa. In farm animals, however, MTZ is currently prohibited in several countries due to insufficient data on nitroimidazoles. The purpose of this study was to assess its pharmacokinetics (PK) in geese after single intravenous (IV) and oral (PO) administrations. Fifteen-month old healthy male geese (n = 8) were used. Geese were subjected to a two-phase, single-dose (10 mg/kg IV, 50 mg/kg PO), open, longitudinal study design with a two-week washout period between the IV and PO phases. Blood was drawn from the left wing vein to heparinized tubes at 0, 0.085 (for IV only), 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, 24, and 48 h. Plasma MTZ concentrations were measured using HPLC coupled to an UV detector, and the data were pharmacokinetically analyzed using PKanalix™ software with a non-compartmental approach. MTZ was still quantifiable and well above the LLOQ at 24 h after both routes of administration. Following IV administration, terminal elimination half-life, volume of distribution, and total clearance were 5.47 h, 767 mL/kg, and 96 mL/h/kg, respectively. For the PO route, the bioavailability was high (85%), and the mean peak plasma concentration was 60.27 μg/mL at 1 h. When parameters were normalized for the dose, there were no statistically significant differences for any of the PK parameters between the two routes of administration. The study shows that oral administration of MTZ seems to be promising in geese, although comprehensive research on its pharmacodynamics and multiple-dose studies are necessary before its adoption in geese can be further considered.

中文翻译：

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静脉和口服给药后甲硝唑在鹅（Anser anser Domesticus）中的药代动力学

甲硝唑（MTZ）是一种5-硝基咪唑类抗菌和抗原虫药。在人类和伴侣动物医学中，MTZ 由于其对抗厌氧细菌和原生动物的功效而仍然被广泛使用。然而，由于有关硝基咪唑的数据不足，目前一些国家禁止在农场动物中使用 MTZ。本研究的目的是评估其在鹅体内单次静脉（IV）和口服（PO）给药后的药代动力学（PK）。 使用15 个月大的健康雄性鹅（n = 8）。鹅接受两阶段、单剂量（10 mg/kg IV，50 mg/kg PO）、开放、纵向研究设计，IV 和 PO 阶段之间有两周的清除期。在 0、0.085（仅用于 IV）、0.25、0.5、0.75、1、1.5、2、4、6、8、10、24 和 48 小时从左翼静脉抽取血液至肝素化管。使用与 UV 检测器联用的 HPLC 测量血浆 MTZ 浓度，并使用 PKanalix™ 软件采用非区室方法对数据进行药代动力学分析。两种给药途径后 24 小时，MTZ 仍然是可量化的并且远高于 LLOQ。IV 给药后，终末消除半衰期、分布容积和总清除率分别为 5.47 小时、767 mL/kg 和 96 mL/h/kg。PO途径的生物利用度很高（85%），1小时平均血浆峰值浓度为60.27 μg/mL。当参数标准化为剂量时，两种给药途径之间的任何 PK 参数都没有统计学上的显着差异。该研究表明，口服 MTZ 在鹅身上似乎很有前景，但在进一步考虑在鹅身上采用之前，还需要对其药效学和多剂量研究进行全面研究。