 Nitazoxanide has also been shown to have "in vitro" antiparasitic activity and clinical treatment efficacy for infections caused by other protozoa and helminths; emerging evidence suggests that it possesses efficacy in treating a number of viral infections as well.Chemically, nitazoxanide is the prototype member of the thiazolides, a class of drugs which are synthetic nitrothiazolyl-salicylamide derivatives with antiparasitic and antiviral activity.Tizoxanide, an active metabolite of nitazoxanide in humans, is also an antiparasitic drug of the thiazolide class.