The nizonide 500mg, containing nitazoxanide, is an antiparasitic medication commonly used to treat worm infections and some protozoal infections in the intestines. It works by inhibiting the energy production of parasites, causing them to die. Nizonide is often prescribed for infections caused by Giardia lamblia or Cryptosporidium parvum, which can lead to symptoms like diarrhea, abdominal cramps, and nausea. This medication should be taken exactly as directed by a healthcare provider, usually twice daily with food. Side effects may include mild nausea, headache, or stomach pain. It’s important to complete the full course even if symptoms improve to ensure complete parasite elimination.