Fipronil (FIP) is an ectoparasiticide of the phenylpyrazole class, used in veterinary medicine in topical form. Supported by evidence of uncontrolled human exposure to FIP and environmental damage caused by commercially available formulations, its use by oral administration has become promising. The effectiveness of FIP against the flea Ctenocephalides felis felis and the tick Rhipicephalus sanguineus and its pharmacokinetics and main active metabolite, fipronil sulfone (SULF) were evaluated after single oral administration of tablets in three different doses (2, 4, and 6 mg/kg) in dogs. Through the plasma concentration curves, it was possible to observe that the FIP showed rapid absorption and metabolization and slow elimination. The values of C_max (β = 0.7653) and AUC_0-t (β = 0.3209) did not increase proportionally with increasing dose. At 48 h after treatment, doses of 4 mg/kg (AUC_0−t = 442.39 ± 137.35 µg/ml*h) and 6 mg/kg (AUC_0−t = 421.32 ± 102.84 µg/ml*h) provided 100% and 99% efficacy against fleas, and 95% and 98% against ticks, respectively. The estimated EC₉₀ of FIP +SULF was 1.30 µg/ml against C. felis felis and 2.16 µg/ml against R. sanguineus. The correlation between the FIP pharmacokinetic and efficacy data demonstrated its potential for oral administration in the form of tablets for the control of ectoparasites in dogs, as a safer alternative for animals, humans, and the environment, aligned with the One Health concept.

中文翻译：

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氟虫腈的口服药代动力学特征和对狗跳蚤和蜱的功效

氟虫腈 (FIP) 是一种苯吡唑类的外寄生虫药，以局部形式用于兽药。有证据表明人类不受控制地暴露于 FIP 和市售制剂造成的环境损害，口服给药已变得很有希望。FIP的对抗跳蚤有效性猫栉首蚤蚤和蜱血红扇头蜱和其药代动力学和主要活性代谢物，氟虫腈砜（SULF）的片剂的单次口服给药后在三个不同的剂量（2,4和6mg / kg的评价) 在狗中。通过血药浓度曲线可以观察到FIP吸收代谢快，消除慢。C _max的值(β = 0.7653) 和 AUC _{0- t} (β = 0.3209) 不随剂量增加成比例增加。治疗后 48 小时，4 mg/kg (AUC _{0- t}  = 442.39 ± 137.35 µg/ml*h) 和 6 mg/kg (AUC _{0- t}  = 421.32 ± 102.84 µg/ml*h) 的剂量提供 100%对跳蚤有 99% 的功效，对蜱有 95% 和 98% 的功效。FIP + SULF 对C的估计 EC ₉₀为 1.30 µg/ml 。felis felis和 2.16 µg/ml 针对R。血腥的. FIP 药代动力学和疗效数据之间的相关性证明了其以片剂形式口服给药以控制狗体外寄生虫的潜力，作为动物、人类和环境的更安全替代方案，符合 One Health 概念。