Nizonide 500mg is an antiparasitic medication primarily containing Nitazoxanide. It is commonly prescribed to treat parasitic infections caused by protozoa such as Giardia lamblia and Cryptosporidium parvum. While effective against specific parasitic infections, nizonide is not suitable for all types of parasitic worms. Its efficacy depends on the type of parasite, and it is generally ineffective against certain helminths (worms). For treating parasitic worm infections like roundworms, tapeworms, or hookworms, alternative medications such as albendazole or mebendazole are often preferred. Always consult a doctor to determine the appropriate treatment and dosage based on the specific parasitic infection.