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Nitazoxanide

Generic name: nitazoxanide systemic

Brand names: Alinia

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Suspension Reconstituted, Oral:

Alinia: 100 mg/5 mL (60 mL) [contains fd&c red #40, sodium benzoate; strawberry flavor]

Tablet, Oral:

Alinia: 500 mg [contains corn starch, fd&c blue #2 aluminum lake, fd&c yellow #10 aluminum lake, fd&c yellow #6 aluminum lake, soybean lecithin]

Pharmacology

Mechanism of Action

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/Pharmacodynamics

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%

Use: Labeled Indications

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

Use: Off Label

Clostridioides (formerly Clostridium) difficile infectionb

Current evidence from small, controlled trials regarding the use of nitazoxanide in the management of C. difficile infection suggests that it may be comparable to the use of oral metronidazole or vancomycin. The

Cryptosporidiosis-associated diarrhea in HIV-infected patientsyes

Based on the US Department of Health and Human Services (HHS) Guidelines for Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, nitazoxanide may be considered as an alternative agent in the management of diarrhea caused by Cryptosporidium in HIV-infected patients (must be used in combination with optimized antiretroviral therapy (ART), electrolyte replacement, and symptomatic treatment and rehydration).

Contraindications

Hypersensitivity to nitazoxanide or any component of the formulation

Dosage and Administration

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 (Musher 2006; Musher 2009; IDSA [McDonald 2018])

Cryptosporidiosis-associated diarrhea in HIV-infected patients (off-label use): Oral: 500 to 1,000 mg twice daily for 14 days (must be used in conjunction with optimized ART, electrolyte replacement, and symptomatic treatment and rehydration) (HHS [OI adult 2015])

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 (HHS [OI pediatric 2013]).

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) (Red Book [AAP 2015]): 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 (HHS [OI pediatric 2013], Red Book [AAP 2015]):

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 (CDC 2012; Red Book [AAP 2015]):

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 (Haffizulla 2014).

Reconstitution

For preparation at time of dispensing, add 48 mL of water incrementally to 60 mL bottle; shake vigorously. Resulting suspension is 20 mg/mL (100 mg per 5 mL).

Administration

Administer with food. Shake suspension well prior to administration.

Dietary Considerations

Some formulations may contain sucrose.

Storage

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Following reconstitution of oral suspension, discard unused portion after 7 days.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

1% to 10%:

Central nervous system: Headache (>2%)

Gastrointestinal: Abdominal pain (>2%), nausea (>2%)

Genitourinary: Urine discoloration (>2%)

<1%, postmarketing, and/or case reports: Diarrhea (exacerbation), dizziness, dyspnea, gastroesophageal reflux disease, skin rash, urticaria

Warnings/Precautions

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 HIV-infected patients.

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.

Pregnancy

Pregnancy Considerations

Adverse events have not been observed in animal reproduction studies. Human data is not available; however, nitazoxanide may be used during pregnancy after the first trimester in women with severe symptoms of cryptosporidiosis (HHS [opportunistic; adult] 2015).

Patient Education

What is this drug used for?

  • It is used to treat diarrhea caused by certain parasite infections.

Frequently reported side effects of this drug

  • Headache
  • Abdominal pain
  • Nausea
  • Urine discoloration

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

  • A significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated January 25, 2020.