In medicine, nitazoxanide is an antiprotozoal agent "5-nitrothiazolyl derivative used for a broad range of intestinal parasitic infections including cryptosporidium and giardia; it is a redox-active nitrothiazolyl-salicylamide prodrug; structure given in first source."[1]
It may also be effective for the treatment of pseudomembranous enterocolitis.[2]