Nitazoxanide is a broad-spectrum antiparasitic and antiviral medication belonging to the thiazolide class of drugs. It is primarily used to treat diarrhea in adults and children caused by protozoa such as Cryptosporidium parvum and Giardia lamblia. The drug functions by inhibiting the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme-dependent electron transfer essential for anaerobic energy metabolism in parasites, leading to their death. Beyond protozoal infections, nitazoxanide exhibits activity against helminths, anaerobic bacteria, and certain viruses, showing potential therapeutic benefits for influenza and hepatitis B.