Drug information of Nitazoxanide

Nitazoxanide

Drug group:

Nitazoxanide is an antiprotozoal medicine that treats infections caused by protozoa (single-cell parasites that live in moist places such as lakes, streams, and soil).
 
Nitazoxanide is used to treat diarrhea caused by Giardia or Cryptosporidium. These conditions are sometimes called "Traveler's diarrhea." Nitazoxanide is used in adults and children who are at least 1 year old.

Nitazoxanide

Mechanism of effect

Nitazoxanide is rapidly metabolized to the active metabolite tizoxanide in vivo. Activity may be due to interference with the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme-dependent electron transfer reaction which is essential to anaerobic metabolism. In vitro, nitazoxanide and tizoxanide inhibit the growth of sporozoites and oocysts of Cryptosporidium parvum and trophozoites of Giardia lamblia.

Pharmacodynamic

Nitazoxanide is rapidly metabolized to the active metabolite tizoxanide in vivo. Activity may be due to interference with the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme-dependent electron transfer reaction which is essential to anaerobic metabolism. In vitro, nitazoxanide and tizoxanide inhibit the growth of sporozoites and oocysts of Cryptosporidium parvum and trophozoites of Giardia lamblia.

Pharmacokinetics

Metabolism
Hepatic, to an active metabolite, tizoxanide. Tizoxanide undergoes conjugation to form tizoxanide glucuronide. Nitazoxanide is not detectable in the serum following oral administration.
 
Excretion
Urine (~33%); feces (~67%)
 
Time to Peak
Plasma: Tizoxanide and tizoxanide glucuronide: 1-4 hours
 
Half-Life Elimination
Tizoxanide: 1 to 1.6 hours
 
Protein Binding
Tizoxanide: >99%

Drug indications

Diarrhea, infectious: Treatment of diarrhea caused by Cryptosporidium parvum or Giardia lamblia

Dosage

Dosing: Adult
Diarrhea, infectious caused by Cryptosporidium parvum or Giardia lamblia: Oral suspension or tablets: 500 mg every 12 hours for 3 days
Clostridioides (formerly Clostridium) difficile infection (off-label use): Oral suspension or tablets: 500 mg every 12 hours for 7 to 10 days
Cryptosporidiosis-associated diarrhea in patients with HIV (off-label use): Oral: 500 mg to 1 g twice daily for 14 days (must be used in conjunction with optimized antiretroviral therapy, electrolyte replacement, symptomatic treatment, and rehydration)
Microsporidiosis-associated diarrhea in patients with HIV (alternative agent) (off-label use): Limited data: Oral: 1 g twice daily for 60 days in combination with optimized antiretroviral therapy, electrolyte replacement, symptomatic treatment, and rehydration)
Dosing: Geriatric
Refer to adult dosing.
Dosing: Pediatric
Note: For doses <500 mg, the oral suspension should be used.
Cryptosporidiosis (Cryptosporidium parvum): Note: In non-HIV patients, usual treatment duration is 3 days (Red Book [AAP 2015]). In HIV-exposed/-positive patients, consistently effective treatment options are lacking; the suggested treatment duration is 3 to 14 days in conjunction with optimized combination antiretroviral therapy
Children 1 to 3 years: Oral: 100 mg every 12 hours
Children 4 to 11 years: Oral: 200 mg every 12 hours
Children ≥12 years and Adolescents: Oral: 500 mg every 12 hours
Fasciola hepatica (sheep liver fluke) : Limited data available:
Children 1 to 3 years: Oral: 100 mg every 12 hours for 7 days
Children 4 to 11 years: Oral: 200 mg every 12 hours for 7 days
Children ≥12 years and Adolescents: Oral: 500 mg every 12 hours for 7 days
Giardiasis (Giardia intestinalis/lamblia/duodenalis); regardless of HIV-status :
Children 1 to 3 years: Oral: 100 mg every 12 hours for 3 days
Children 4 to 11 years: Oral: 200 mg every 12 hours for 3 days
Children ≥12 years and Adolescents: Oral: 500 mg every 12 hours for 3 days
Hymenolepis nana (dwarf tapeworm): Limited data available
Children 1 to 3 years: 100 mg twice daily for 3 days
Children 4 to 11 years: 200 mg twice daily for 3 days
Children ≥12 years and Adolescents: Oral: 500 mg twice daily for 3 days
Influenza; acute uncomplicated: Limited data available: Children ≥12 years and Adolescents: Oral: 600 mg twice daily for 5 days; in a double-blind, placebo controlled trial of 624 subjects (age range: 12 to 65 years), a 5-day course was reported to shorten the duration of symptoms .

Drug contraindications

Hypersensitivity to nitazoxanide or any component of the formulation

Side effects

Side effects requiring immediate medical attention
Along with its needed effects, nitazoxanide may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking nitazoxanide:

Incidence not known

Diarrhea

Interactions

Isoniazid , Rifampin , ritonavir , Efavirenz
There are no known significant interactions.

Alerts

Disease-related concerns:
 
  • HIV: Nitazoxanide had not been studied for treatment of diarrhea caused by G. lamblia in patients with HIV infection. Nitazoxanide has not been shown to be superior to placebo for treatment of diarrhea caused by C. parvum in patients with HIV.
 
Special populations:
 
  • Immunocompromised patients: Nitazoxanide had not been studied for treatment of diarrhea caused by G. lamblia in patients with immunodeficiency. Nitazoxanide has not been shown to be superior to placebo for treatment of diarrhea caused by C. parvum in patients with immunodeficiency.
 
Dosage form specific issues:
 
  • Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity ("gasping syndrome") in neonates; the "gasping syndrome" consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC 1982); some data suggest that benzoate displaces bilirubin from protein-binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer's labeling.

Points of recommendation

Administer with food. Shake suspension well prior to administration

Pregnancy level

Human data are not available; however, nitazoxanide may be used during pregnancy after the first trimester in women with severe symptoms of cryptosporidiosis .

Breast feeding warning


Limited information indicates that a maternal dose of 500 mg of nitazoxanide produces low levels of an active metabolite, tizoxanide, in breastmilk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. But until more data become available, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Related drugs

Albendazol , Tinidazole , Mebendazol


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