The pharmacokinetics and bioavailability of furosemide were determined following intravenous (IV), intramuscular (IM), and subcutaneous (SC) administrations at 2.5 mg/kg dose in sheep. The study was conducted on six healthy sheep in a three-way, three-period, crossover pharmacokinetic design with a 15-day washout period. In first period, furosemide was randomly administered via IV to 2 sheep, IM to 2 sheep and SC to 2 sheep. In second and third periods, each sheep received furosemide via different routes of administration with the 15-day washout period. Plasma concentrations were determined using a high-performance liquid chromatography assay and analyzed by noncompartmental method. The mean total clearance and volume of distribution at steady state following IV administration were 0.24 L h^-1 kg^-1 and 0.17 L/kg, respectively. The elimination half-life was similar for all administration routes. The mean peak plasma concentrations of IM and SC administration were 10.33 and 3.18 μg/ml at 0.33 and 0.42 hr, respectively. The mean bioavailability of IM and SC administration was 97.91% and 37.98%, respectively. The IM injection of furosemide may be the alternative routes in addition to IV. However, further research is required to determine the effect of dose and route of administration on the clinical efficacy of furosemide in sheep.

中文翻译：

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速尿在绵羊体内的药代动力学和生物利用度

在绵羊中以 2.5 mg/kg 剂量静脉内 (IV)、肌肉内 (IM) 和皮下 (SC) 给药后测定呋塞米的药代动力学和生物利用度。该研究在六只健康羊身上进行，采用三向、三期、交叉药代动力学设计，洗脱期为 15 天。在第一阶段，呋塞米通过IV随机给予2只羊，IM给予2只羊，SC给予2只羊。在第二阶段和第三阶段，每只羊通过不同的给药途径接受呋塞米，洗脱期为 15 天。使用高效液相色谱法测定血浆浓度并通过非隔室法进行分析。IV 给药后稳态的平均总清除率和分布容积为 0.24 L h ^-1  kg ^-1和 0.17 L/kg，分别。所有给药途径的消除半衰期相似。在 0.33 和 0.42 小时，IM 和 SC 给药的平均峰值血浆浓度分别为 10.33 和 3.18 μg/ml。IM 和 SC 给药的平均生物利用度分别为 97.91% 和 37.98%。速尿 IM 注射可能是除 IV 外的替代途径。然而，需要进一步的研究来确定剂量和给药途径对绵羊呋塞米临床疗效的影响。