Fipronil is a broad-spectrum second-generation phenylpyrazole insecticide. It is used frequently as an agricultural and veterinary pesticide. It is used 'off-label' as a topical spray to treat flea, tick, lice, and certain species of mite infestations in pet poultry.
Fipronil works by blocking the glutamate-gated GABA (gamma-aminobutyric acid) chloride channels in nerve cells, resulting in overexcited nervous systems of the parasites, killing them quickly.
