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Pharmacological particulars
Pharmacotherapeutic group: Antiparasitic product, insecticides and repellent. Other ectoparasiticides for topical use, fipronil
ATCvet code: QP53AX15
Pharmacodynamic properties
Fipronil is an insecticide/acaricide in the phenylpyrazole family. It acts by inhibiting the GABA complex, binding to the chloride channel and thereby blocking pre- and post-synaptic transfer of chloride ions across the membrane. This results in uncontrolled activity of the central nervous system and death in insects and acarids.
Fipronil exhibits insecticidal activity against fleas (Ctenocephalides felis), and acaricidal activity against ticks (Dermacentor reticulatus) in the cat.
Newly arriving fleas are killed within 24 hours of landing on the animal.
The product is effective against flea infestation for approximately 5 weeks and against tick (Dermacentor reticulatus) infestations for 2 weeks, depending on the level of challenge.
Pharmacokinetic properties
Fipronil is mainly metabolised to its sulfone derivative (RM1602), which also possesses insecticidal and acaricidal properties.
After a local application of fipronil to the cat, systemic absorption is negligible.
The concentrations of fipronil on the hair decrease with time.