Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand.
Department of Veterinary Sciences, University of Pisa, San Piero a Grado, Italy.
J Vet Pharmacol Ther. 2020 Jul;43(4):307-312. doi: 10.1111/jvp.12850. Epub 2020 Feb 29.
The aim of the present study was to elucidate the pharmacokinetic profiles of amoxicillin trihydrate (AMX) in Siamese freshwater crocodiles (Crocodylus siamensis). Crocodiles were administered a single intramuscular injection of AMX, at a dose of either 5 or 10 mg/kg body weight (b.w.). Blood samples were collected at preassigned times up to 120 hr. The plasma concentrations of AMX were measured using a validated liquid chromatography tandem-mass spectrometry method. AMX plasma concentrations were quantifiable for up to 72 hr (5 mg/kg b.w.) and 96 hr (10 mg/kg b.w.). The elimination half-life (t ) of AMX following dosing at 5 mg/kg b.w. (8.72 ± 0.61 hr) was almost identical to that following administration at 10 mg/kg b.w (8.98 ± 1.13 hr). The maximum concentration and area under the curve from zero to the last values of AMX increased in a dose-dependent fashion. The average binding percentage of AMX to plasma protein was 21.24%. Based on the pharmacokinetic data, susceptibility break point, and the surrogate PK-PD index (T > MIC, 0.25 μg/ml), intramuscular administration of AMX at dose of 5 mg/kg b.w. every 4 days might be appropriate for the treatment of susceptible bacterial infections in freshwater crocodiles.
本研究旨在阐明三水合阿莫西林（AMX）在暹罗淡水鳄（Crocodylus siamensis）中的药代动力学特征。给鳄鱼肌肉内注射单剂量的 AMX，剂量分别为 5 或 10 mg/kg 体重。在预定的时间内采集至 120 小时的血样。使用经验证的液相色谱串联质谱法测定 AMX 的血浆浓度。AMX 血浆浓度可定量测定长达 72 小时（5 mg/kg b.w.）和 96 小时（10 mg/kg b.w.）。以 5 mg/kg b.w.剂量给药后，AMX 的消除半衰期（t ）（8.72 ± 0.61 小时）几乎与 10 mg/kg b.w.（8.98 ± 1.13 小时）给药后的半衰期相同。最大浓度和 AMX 的零至最后值的曲线下面积呈剂量依赖性增加。AMX 与血浆蛋白的平均结合百分比为 21.24%。根据药代动力学数据、药敏折点和替代药代动力学-药效学指数（T > MIC，0.25 μg/ml），每 4 天肌肉内注射 AMX 5 mg/kg b.w.可能适用于治疗淡水鳄易感细菌感染。
