Levamisole (Ergamisol, HCl salt)'s an antibiotic belonging to a class of synthetic imidazothiazole derivatives. It was discovered at Janssen Pharmaceutica in 1966. Clinical use It was originally used as an antihelminthic to treat worm infestations in both humans and animals. Most commercial preparations are intended for veterinary use as a dewormer for cattle, pigs, and sheep. However, it's also gained prominence among aquarists as an effective treatment for Camallanus roundworm infestations in… (More on Levamisole)