There is limited investigation of neonatal foal pharmacokinetic parameters for the antimicrobial combination of sulfadiazine (SDZ) and trimethoprim (TMP). Neonatal pharmacokinetic investigation of the sulfadiazine–trimethoprim combination is required to ensure safe and effective utilization in this population. The purpose of this study was to determine the pharmacokinetics of sulfadiazine–trimethoprim in five healthy neonatal foals with oral administration at 24 mg/kg every 12 hr (hrs) for 10 days. Blood samples were collected at serial time points at approximately 72 hr of age (steady-state) and at days 5 and 10 to monitor the influence of age within the neonatal period. Pharmacokinetic parameters were determined using a one-compartment model analysis, and mean ± SD was calculated. C_max was 37.8 ± 13.4 μg/ml (SDZ) and 1.92 ± 0.25 μg/ml (TMP). T_max was 1.4 ± 0.6 hr (SDZ) and 1.4 ± 0.4 hr (TMP). C_min for SDZ and TMP was 16.84 ± 8.46 μg/ml and 0.46 ± 0.24 μg/ml, respectively. Elimination half-life was 10.8 ± 6.1 hr (SDZ) and 6.5 ± 2 hr (TMP). AUC_{0 → ∞} was 667 ± 424 μg × hr/ml (SDZ) and 21.1 ± 5.3 μg × hr/ml (TMP). Foals remained healthy, and the plasma concentration of sulfadiazine–trimethoprim reached levels above MIC₍₉₀₎ for Streptococcus equi ssp. (SDZ/TMP): 9.5/0.5 μg/ml).

中文翻译：

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磺胺嘧啶和甲氧苄啶混悬液在新生儿中的药代动力学

对磺胺嘧啶 (SDZ) 和甲氧苄啶 (TMP) 的抗菌组合的新生小马驹药代动力学参数的研究有限。需要对磺胺嘧啶-甲氧苄啶组合进行新生儿药代动力学研究，以确保在该人群中安全有效地使用。本研究的目的是确定每 12 小时 (hrs) 每 12 小时 (hrs) 口服 24 mg/kg 的五只健康新生小马驹中磺胺嘧啶-甲氧苄啶的药代动力学，持续 10 天。在大约 72 小时（稳态）和第 5 天和第 10 天的连续时间点收集血液样本，以监测新生儿期年龄的影响。使用一室模型分析确定药代动力学参数，并计算平均值±  SD。ç_最大为 37.8 ± 13.4 μg/ml (SDZ) 和 1.92 ± 0.25 μg/ml (TMP)。T _max为 1.4 ± 0.6 小时 (SDZ) 和 1.4 ± 0.4 小时 (TMP)。SDZ 和 TMP 的C _{min 分别}为 16.84 ± 8.46 μg/ml 和 0.46 ± 0.24 μg/ml。消除半衰期为 10.8 ± 6.1 小时 (SDZ) 和 6.5 ± 2 小时 (TMP)。AUC _{0 → ∞}为 667 ± 424 μg × hr/ml (SDZ) 和 21.1 ± 5.3 μg × hr/ml (TMP)。小马驹保持健康，磺胺嘧啶-甲氧苄啶的血浆浓度达到了马链球菌属的MIC ₍₉₀₎以上水平。(SDZ/TMP)：9.5/0.5 μg/ml)。