Description
Nizonide (Nitazoxanide) 500 mg
Nizonide 500 mg is a branded medicine containing nitazoxanide. Nitazoxanide is an antiparasitic, with activity against certain intestinal protozoa. The verified U.S. prescribing information identifies nitazoxanide tablets as an oral antiprotozoal medicine.
Active Ingredient and Medicine Class
Active ingredient: nitazoxanide.
Medicine class: antiprotozoal / antiparasitic agent. Nitazoxanide is the active ingredient used in approved tablet formulations for oral use.
Established Medical Uses
According to the FDA/DailyMed prescribing information, nitazoxanide tablets are indicated for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum in patients 12 years of age and older. Clinical trials have also evaluated nitazoxanide in diarrheal illness caused by Entamoeba histolytica and/or E. dispar, but these uses are not the approved U.S. tablet indication.
How It Works
Nitazoxanide is thought to interfere with essential metabolic processes in susceptible parasites. In general terms, it disrupts pathways the organisms need to survive and multiply in the intestine. Its exact mechanism has been described as affecting parasite energy metabolism.
Important Safety Information
Nitazoxanide should not be used in patients with known hypersensitivity to nitazoxanide or any tablet component. The label notes that safety and effectiveness are not established in younger children for the tablet formulation. Important precautions include possible effects when used with other highly protein-bound medicines with narrow therapeutic indexes, such as warfarin, because competition for binding sites may occur.
The label also advises that nitazoxanide has not been adequately studied in certain populations, including pregnancy, so official prescribing information should be reviewed before use.
Possible Side Effects
Reported adverse effects include gastrointestinal symptoms such as abdominal pain, nausea, vomiting, and diarrhea, as well as headache and discoloration of urine. Serious hypersensitivity reactions are uncommon but possible, as with many medicines.
Scientific Evidence
Randomized clinical studies support nitazoxanide’s activity against some intestinal protozoal infections. In adults and adolescents with diarrhea caused by Giardia intestinalis or Entamoeba histolytica/E. dispar, nitazoxanide improved clinical resolution compared with placebo. A pediatric trial found nitazoxanide to be comparably effective to metronidazole for giardiasis, and another randomized study found benefit in cryptosporidiosis.
Medical Information Notice
This page is an educational summary based on sources available at the time of review and does not replace the official patient leaflet or individual assessment by a qualified healthcare professional.
Medical Sources
- U.S. Food and Drug Administration / DailyMed: Nitazoxanide Tablets, Prescribing Information
- Rossignol JF, Ayoub A, Ayers MS.: Treatment of diarrhea caused by Giardia intestinalis and Entamoeba histolytica or E. dispar: a randomized, double-blind, placebo-controlled study of nitazoxanide. Journal of Infectious Diseases. 2001.
