Ivermectin is one of the most important drugs in veterinary and human medicine for the control of parasitic infection and was the joint focus of the 2015 Nobel Prize in Physiology or Medicine, some 35 years after its remarkable discovery. Although best described for its activity on glutamate-gated chloride channels in parasitic nematodes, understanding of its mode of action remains incomplete. In the field of veterinary medicine, resistance to ivermectin is now widespread, but the mechanisms underlying resistance are unresolved. Here we discuss the history of this versatile drug and its use in global health. Based on recent studies in a variety of systems, we question whether ivermectin could have additional modes of action on parasitic nematodes.
Ligand-gated ion channels, particularly glutamate-gated chloride channels, are well characterised as the targets of IVM in nematodes and insects.
Nematode genomes are helping to cast light on the diversity of ion-channel subunits in different parasite species of human and veterinary importance.
Resistance to IVM is an increasing problem in the control of parasitic nematodes, and resolving the mechanisms is an important research priority.
Recent studies in other biological systems suggest that IVM can affect a number of additional pathways.
IVM may have novel applications in the treatment and control of important human diseases.