1.1. Adults
Nitazoxanide is FDA-approved for the management of diarrhea caused by Giardia lamblia or Cryptosporidium parvum. Adult dosage recommendations for nitazoxanide are summarized in Table 1. Dosages exceeding these recommendations will be reviewed.
| Treatment Indication | Available Dosage Strengths | Maximum Recommended Dosage |
|---|---|---|
| Diarrhea caused by G. lamblia or C. parvum | 500 mg tablet, 100 mg/5ml suspension | 1 tablet (500 mg) or 25 ml of oral suspension every 12 hours with food for 3 days |
Although not FDA-approved, nitazoxanide 500 mg twice daily for 10 days has demonstrated comparable efficacy to metronidazole in managing Clostridioides difficile colitis in both patients responsive and resistant to metronidazole therapy. Additionally, nitazoxanide may be proven comparable in efficacy to vancomycin in treating C. difficile colitis, although current sample sizes are too small to assess clinical significance. Although several studies have demonstrated possible efficacy and off-label use occurs, nitazoxanide is not currently a guideline recommended therapy for C. diff. infection 4-6.
Nitazoxanide has also shown benefit in treating diarrhea caused by intestinal parasites other than G. lamblia as well as rotavirus but does not yet possess FDA approval for these indications 7-11.
Nitazoxanide has improved eradication rates compared to standard triple therapy when used as part of a four-drug treatment regimen for Helicobacter pylori in treatment-naïve patients but is not FDA-approved for this indication 12-13.
Nitazoxanide, while not FDA-approved, may be considered as an alternative treatment to manage Cryptosporidium-associated diarrhea in adult and adolescent human immunodeficiency virus patients. Dosages utilized are 500 mg to 1000 mg orally twice daily for 14 days to 8 weeks in conjunction with optimized antiretroviral therapy, electrolyte replacement, treatment of symptoms as well as rehydration 14-16.