A mixture of mostly avermectin H2B1a (RN 71827-03-7) with some avermectin H2B1b (RN 70209-81-3), which are macrolides from STREPTOMYCES avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other CHLORIDE CHANNELS. It is a broad spectrum antiparasitic that is active against microfilariae of ONCHOCERCA VOLVULUS but not the adult form.

An orally bioavailable macrocyclic lactone derived from Streptomyces avermitilis, with antiparasitic and potential anti-viral activities. Upon administration, ivermectin exerts its anthelmintic effect through binding and activating glutamate-gated chloride channels (GluCls) expressed on nematode neurons and pharyngeal muscle cells. This causes increased permeability of chloride ions, causing a state of hyperpolarization and results in the paralysis and death of the parasite. Ivermectin may exerts its antiviral effect, including its potential activity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), by binding to the importin (IMP) alpha/beta1 heterodimer, which is responsible for the nuclear import of viral proteins such as the integrase (IN) protein. This inhibits nuclear import of host and viral proteins and may inhibit viral replication.