Pharmacokinetic profile and efficacy against Ctenocephalides felis felis and Rhipicephalus sanguineus administered orally in Beagles dogs
Ectoparasites, phenylpyrazoles, pharmacokinetics, veterinary medicine
The pharmacokinetics of fipronil (FIP) and fipronil-sulfone (SULF), its main active metabolite, were evaluated after oral administration of tablets in three different doses (2, 4 and 6 mg / kg) in dogs, in a single treatment . From the plasma concentration curves it was possible to observe that FIP showed rapid absorption and metabolization and slow elimination. The values of Cmax (β = 0.7653) and AUC0-t (β = 0.3209) did not increase proportionally with the dose. At 48h after treatment, doses of 4 (AUC0-t = 442.39 ± 137.35 µg / mL * h) and 6 mg / kg (AUC0-t = 421.32 ± 102.84 µg / mL * h ) showed efficacy of 100 and 99% respectively for fleas, and for ticks of 95 and 98%. The estimated EC90 for FIP + SULF were 1.30 µg / mL for C. felis felis and 2.16 µg / mL for R. sanguineus, 48h after infestation. It was possible to demonstrate the potential of FIP to be used orally to control ectoparasites in dogs, which in addition to providing greater convenience in administration is a safer alternative for animals, humans and the environment, in line with the concept of One Health .