The avermectins are a series of macrocyclic lactone derivatives with potent anthelmintic properties. Other anthelmintics derived from the avermectins include ivermectin, selamectin, doramectin and abamectin. History In 1978, an actinomycete was isolated at The Kitasato Institute from a soil sample collected at Kawana, Ito City, Shizuoka Prefecture, Japan. Later that year, the isolated actinomycete was sent to Merck Sharp & Dohme Research Laboratories for testing. Various, carefully controlled br… (More on Avermectin)