Fluralaner (A1443) is an isoxazoline ectoparasiticide. It potently and selectively inhibits binding of the GABA receptor channel blocker EBOB to housefly head membranes (IC50: 455 pM).

GABA:455 pM

A1443 inhibits specific binding of the gamma-aminobutyric acid (GABA) receptor channel blocker EBOB to housefly-head membranes, with an IC(50) value of 455pM. In contrast, the IC(50) value in rat-brain membranes is>10muM. A1443 blocks GABA- and glutamate-induced chloride currents in Xenopus oocytes expressing MdGBCl or MdGluCl channels, with IC(50) values of 5.32 and 79.9 nM, respectively [1]. Fluralaner potently inhibited flea reproduction capacity in vitro. Oviposition ceased completely at concentrations as low as 25.0 ng/mL. While no ovicidal effect was observed, fluralaner exerted a larvicidal effect at exceptionally low concentrations (6.25 ng/mL) [2].

In the simulated flea-infested home environment, flea-control efficacy on fluralaner-treated dogs was >99% at every time point measured for 12 weeks. No adverse events were observed in fluralaner-treated dogs [2]. No adverse events were observed subsequent to fluralaner treatment of MDR1(-/-) Collies at three times the highest expected clinical dose [3].