Studies have shown a wide safety margin and at the recommended dosage, no adverse effects on breeding performance were observed. Virbamec Injectable Solution can be used in breeding ewes and rams and will not affect fertility. At therapeutic doses, ivermectin has no adverse effect on cattle, pigs or sheep since it does not readily penetrate their central nervous systems.

Transitory discomfort has occasionally been observed in some cattle, pigs and sheep following subcutaneous administration. A low incidence of soft tissue swelling at the injection site has been observed in those species. These reactions have disappeared without treatment.

Ivermectin is a highly active, broad spectrum, internal and external parasiticide of the avermectin family.

Ivermectins are isolated after fermentation of the soil organism Streptomyces avermitilis. Ivermectin stimulates the release of gamma amino butyric acid (GABA) at presynaptic nerve terminals (in nematodes) or the neuromuscular junctions (in arthropods, acarids, flies and fleas), leading to the paralysis and death of the parasite concerned.

Virbamec Injectable Solution provides a large safety margin to mammals when used at the recommended dosage. Acetylcholine, the main peripheral neurotransmitter, is not affected by ivermectin. Furthermore, ivermectin does not enter the central nervous system in the mammals, where GABA acts as neurotransmitter.