Afoxolaner (INN[5]) is an insecticide and acaricide that belongs to the isoxazoline chemical compound group.

It acts as an antagonist at GABA-receptors (those gated by the neurotransmitter gamma-aminobutyric acid) and other ligand-gated chloride channels.

Prolonged afoxolaner-induced hyperexcitation results in uncontrolled activity of the central nervous system and death of insects and acarines.

The Committee for Medicinal Products for Veterinary Use (CVMP) therefore concluded that binding to dog, rat or human GABA receptors is expected to be low for afoxolaner.

[13] The selectivity might be explained by the number of pharmacological differences that exist between GABA-gated chloride channels of insects and vertebrates.