Nizonide 500mg tablets contain nitazoxanide, an antiparasitic and antiviral medication used to treat diarrhea and worm infections. It is effective against Giardia and Cryptosporidium, common causes of diarrhea. Additionally, Nizonide is used to combat various intestinal worms, including roundworms and tapeworms. The typical dosage is prescribed by a healthcare professional, based on the patient's age and condition. Nizonide works by inhibiting the growth of parasites, leading to their eventual elimination from the body. Common side effects include nausea, abdominal pain, and headaches. Always consult a doctor before starting treatment to ensure safety and proper use.