Ivermectin glutamate-gated chloride channel

Ivermectin binds selectively and with high affinity to glutamate gated chloride ion channels in invertebrate nerve and muscle cells. This leads to an increase in the permeability of cell membrane to chloride ions with hyperpolarization of nerve of muscle cell, resulting in paralysis and death of the parasite. 

There are five macrocyclic lactones utilized in veterinary practice of which ivermectin (an aver-mectin) and moxidectin (a milbemycin) are approved for use in the horse. Ivermectin and moxidectin selectively paralyze parasites by increasing muscle chloride permeability through interaction with glutamate-gated chloride ion channels (McKellar Benchaoui 1996). There is evidence that ivermectin and moxidectin may have several sites of action within the parasite and the effects of these compounds may also differ between the nematode species (McKellar Benchaoui 1996, Martin 1997). 

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