Nitazoxanide is a synthetic nitrothiazolyl-salicylamide derivative and an antiprotozoal agent. Nitazoxanide is a light yellow crystalline powder. It is poorly soluble in ethanol and practically insoluble in water. The anti-protozoal activity of nitazoxanide is believed to be due to interference with the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme dependent electron transfer reaction which is essential to anaerobic energy metabolism. The mechanism appears to be by selectively blocking the maturation of the viral hemagglutinin at a stage preceding resistance to endoglycosidase H digestion. Nitazoxanide is a first-line choice for the treatment of illness caused by Cryptosporidium parvum or Giardia lamblia infection in immunocompetent adults and children, and is an option to be considered in the treatment of illness caused by other protozoa and/or helminths.