Nitazoxanide

Clinical summary

Indications and usage 1 INDICATIONS & USAGE Diarrhea caused by Giardia lamblia or Cryptosporidium parvum: Nitazoxanide tablets (patients 12 years and older) are indicated for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum . Limitations of Use Nitazoxanide tablets have not been shown to be effective for the treatment of diarrhea caused by Cryptosporidium parvum in HIV-infected or immunodeficient patients [see Clinical Studies (14.2)]. Nitazoxanide tablet is an antiprotozoal indicated for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum (1). Limitations of Use: Nitazoxanide tablet has not been shown to be effective for the treatment of diarrhea caused by C. parvum in HIV-infected or immunodeficient patients (1). Dosage and administration 2 DOSAGE & ADMINISTRATION Nitazoxanide tablets should not be administered to pediatric patient 11 years of age or younger (2.1). Dosage for treatment of diarrhea caused by G. lamblia or C. parvum (2.1): Age Dosage Duration 12 years and older One nitazoxanide tablet (500 mg nitazoxanide) every 12 hours with food 3 days 2.1 Recommended Dosage and Important Administration Instructions Important Administration Instructions for Pediatric Patients 11 years of Age or Younger: Nitazoxanide tablets should not be administered to pediatric patients 11 years of age or younger because a single tablet contains a greater amount of nitazoxanide than the recommended dosing in this pediatric age group. Table 1. Recommended Dosage Age Dosage Duration 12 years and older One nitazoxanide tablet (500 mg nitazoxanide) taken orally every 12 hours with food. 3 days Drug interactions 7 DRUG INTERACTIONS Competition for binding sites may occur when administered concurrently with other highly plasma protein-bound drugs with narrow therapeutic indices. Monitor for adverse reactions (7). 7.1 Highly Protein Bound Drugs with Narrow Therapeutic Indices Tizoxanide (the active metabolite of nitazoxanide) is highly bound to plasma protein (>99.9%). Therefore, monitor for adverse reactions when administering nitazoxanide concurrently with other highly plasma protein-bound drugs with narrow therapeutic indices, as competition for binding sites may occur (e.g., warfarin). Pregnancy 8.1 Pregnancy Risk Summary There are no data with nitazoxanide in pregnant women to inform a drug-associated risk. No teratogenicity or fetotoxicity was observed in animal reproduction studies with administration of nitazoxanide to pregnant rats and rabbits during organogenesis at exposures 30 and 2 times, respectively, the exposure at the maximum recommended human dose of 500 mg twice daily based on body surface area (BSA). In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data Nitazoxanide was administered orally to pregnant rats at doses of 0, 200, 800 or 3200 mg/kg/day on gestation days 6 to 15. Nitazoxanide produced no evidence of systemic maternal toxicity when administered once daily via oral gavage to pregnant female rats at levels up to 3200 mg/kg/day during the period of organogenesis. In rabbits, nitazoxanide was administered at doses of 0, 25, 50, or 100 mg/kg/day on gestation days 7 to 20. Oral treatment of pregnant rabbits with nitazoxanide during organogenesis resulted in minimal maternal toxicity and no external fetal anomalies.