Dosage Forms. Tablet: 500 mg; Suspension: 100 mg/5 mL
Common FDA Label Indication, Dosing, and Titration.
1. Diarrhea caused by Cryptosporidium parvum or Giardia lamblia: Adults: 500 mg po bid × 3 d; Children 1-3 y: 100 mg bid × 3 d; Children 4-11 y: 200 mg bid × 3 d
1. Clostridium difficile-associated diarrhea: 500 mg po bid
MOA. Interference with the pyruvate ferredoxin oxidoreductase (PFOR) enzyme-dependent electron transfer reaction, which is essential to anaerobic metabolism or protozoans.
Drug Characteristics: Nitazoxanide
Medication Safety Issues: Nitazoxanide
Drug Interactions: Nitazoxanide. None
Adverse Reactions: Nitazoxanide
Efficacy Monitoring Parameters. Resolution of signs and symptoms of infection.
Toxicity Monitoring Parameters. Consider LFTs and CBC prior to therapy.
Key Patient Counseling Points. Complete full course of therapy; take with food.
Clinical Pearls. Suspension bioavailability is 70% of tablet, not interchangeable. Preferred agent for treating Cryptosporidium diarrhea in immunocompetent adults, has not been proven to be superior to placebo in HIV-infected individuals. Equivalent efficacy to metronidazole for C difficile and Giardia, however, based on cost metronidazole remains the treatment of choice.