History of avermectin and ivermectin, with notes on the history of other macrocyclic lactone antiparasitic agents. - PubMed - NCBI

I use the name avermectin to refer to the family of drugs in general terms. I don't know if this use is widely accepted. Different manufacturers use different names for their products as the patents have expired.

It was fun reading. The drug interrupts neurotransmitters and receptors at a junction that does not exist in vertebrates so it is practically non toxic to them - us.

As with most drugs overuse is leading to resistance.