Abamectin B1b (Avermectin B1b) is a macrocyclic lactone containing an isopropyl reside in the 25-position broad anthelmintic activity. The oral administration of this formulation of avermectin B1 appeared to be highly efficacious against intestinal strongyles and Onchocera microfilaria. Avermectin B1b is a component of marketed and provided commercially Abamectin, which is used to control livestock parasitic nematodes. It is a broad-spectrum acaricide with additional insecticidal action on a limited number of insects. Abamectin acts on insects by increasing the membrane permeability to chloride ions, and it mainly stimulates the release of Ȗ-aminobutyric acid (GABA). The affected arthropod becomes paralysed, stops feeding, and dies after a few days. It exerts contact and stomach action, with limited plant systemic activity, but exhibits translaminar movement into treated leaves. Abamectin is also used as an anthelmintic drug in veterinary medicine.

Avermectin B1a (AVM B1a), a widely used insecticide and acaricide, is reported to both activate and inhibit gamma-aminobutyric acidA (GABA(A)) receptor function in mammalian brain. Avermectin B1a is an antiparasitic agent that paralyzes nematodes without causing hypercontraction or flaccid paralysis. AVM B1a binds to two different sites in the GABA-gated chloride channel with dual effects, i.e., activating the channel on binding to the high-affinity site and blocking it on further binding to the low-affinity site.

Ivermectin is a broad-spectrum anti-parasite medication. It was first marketed under the name Stromectol® and used against worms (except tapeworms), but, in 2012, it was approved for the topical treatment of head lice infestations in patients 6 months of age and older, and marketed under the name Sklice™ as well. Ivermectin is mainly used in humans in the treatment of onchocerciasis but is also effective against other worm infestations (such as strongyloidiasis, ascariasis, trichuriasis, and enterobiasis). Ivermectin binds selectively and with high affinity to glutamate-gated chloride ion channels in invertebrate muscle and nerve cells of the microfilaria. This binding causes an increase in the permeability of the cell membrane to chloride ions and results in hyperpolarization of the cell, leading to paralysis and death of the parasite. Ivermectin also is believed to act as an agonist of the neurotransmitter gamma-aminobutyric acid (GABA), thereby disrupting GABA-mediated central nervous system (CNS) neurosynaptic transmission. Ivermectin may also impair the normal intrauterine development of O. volvulus microfilariae and may inhibit their release from the uteri of gravid female worms. It is sold under brand names Heartgard, Sklice and Stromectol in the United States, Ivomec worldwide by Merial Animal Health, Mectizan in Canada by Merck, Iver-DT in Nepal by Alive Pharmaceutical and Ivexterm in Mexico by Valeant Pharmaceuticals International. In Southeast Asian countries, it is marketed by Delta Pharma Ltd. under the trade name Scabo 6.