Pharmacodynamic properties
Eprinomectin is a molecule with an endectocidal activity belonging to the macrocyclic lactone class. Compounds of the class bind with high affinity to glutamate-gated chloride ion channels which occur in invertebrate nerve or muscle cells. These compounds bind selectively to these channels, which leads to an increase in the permeability of the cell membrane to chloride ions with hyperpolarization of the nerve or muscle cell, resulting in paralysis and death of the parasite.
Compounds of this class may also interact with other ligand-gated chloride channels, such as those gated by the neurotransmitter GABA (gamma-aminobutyric acid).

Pharmacokinetic particulars
The bioavailability of topically applied eprinomectin in cattle is about 30% with most absorption occurring by about 10 days after treatment. Eprinomectin is strongly linked to plasma proteins (99%). Eprinomectin is not extensively metabolized in cattle following topical administration.
Faeces are the major route of elimination.

Environmental properties
Like other macrocyclic lactones, eprinomectin has the potential to adversely affect non-target organisms (See section 4.5 other precautions).