Ivermectin is 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.
Ivermectin (MK-933) is a specific inhibitor of Impα/β1-mediated nuclear import and has potent antiviral activity towards both HIV-1 and dengue virus. It is a positive allosteric effector of P2X4 and the α7 neuronal nicotinic acetylcholine receptor (nAChRs).
Ivermectin also inhibits bovine herpesvirus1 (BoHV-1) replication and inhibits BoHV-1 DNA polymerase nuclear import.
Ivermectin is a candidate therapeutic against SARS-CoV-2/COVID-19.

[2] Wagstaff KM, et al. Ivermectin is a specific inhibitor of importin α/β-mediated nuclear import able to inhibit replication of HIV-1 and dengue virus. Biochem J. 2012 May 1;443(3):851-6.

[3] Raza S, et al. Ivermectin Inhibits Bovine Herpesvirus 1 DNA Polymerase Nuclear Import and Interferes with Viral Replication. Microorganisms. 2020 Mar 13;8(3). pii: E409.