Classifications: antiprotozoal;
Therapeutic: antiprotozoal

Prototype: Metronidazole
Pregnancy Category: B


100 mg/5 mL oral suspension; 500 mg tablets


Antiprotozoal activity believed to be due to interference with an essential enzyme needed for anaerobic energy metabolism in protozoa. Interference with the enzyme may not be the only pathway by which nitazoxanide exhibits antiprotozoal activity.

Therapeutic Effect

Inhibits growth of sporozoites and oocysts of Cryptosporidium parvum and trophozoites of Giardia lamblia.


Treatment of diarrhea caused by Cryptosporidium parvum and Giardia lamblia.


Prior hypersensitivity to nitazoxanide.

Cautious Use

Hepatic and biliary disease, renal disease, renal impairment, renal failure, and combined renal and hepatic disease; pregnancy (category B); lactation. Safety and efficacy in children <1 y or >11 y have not been studied.

Route & Dosage

Adult: PO 500 mg q12h x 3 d
Child: PO 12–47 mo, 100 mg q12h x 3 d; 4–11 y, 200 mg q12h x 3 d


  • Prepare suspension as follows: Tap bottle until powder loosens. Draw up 48 mL of water, add half to bottle, shake to suspend powder, then add remaining 24 mL of water and shake vigorously.
  • Give required dose (5 or 10 mL) with food.
  • Keep container tightly closed, and shake well before each administration.
  • Suspension may be stored for 7 d at 15°–30° C (59°–86° F), after which any unused portion must be discarded.

Adverse Effects (≥1%)

CNS: Headache. GI: Abdominal pain, diarrhea, vomiting.


Food: Increases levels.


Peak: 1–4 h. Distribution: 99% protein bound. Metabolism: Rapidly hydrolyzed in liver to an active metabolite, tizoxanide (desacetyl-nitazoxanide). Elimination: In urine, bile, and feces.

Nursing Implications

Assessment & Drug Effects

  • Monitor for therapeutic effectiveness: No watery stools and ≤2 soft stools with no hematochezia within the past 24 h or no symptoms and no unformed stools within the past 48 h.
  • Monitor closely patients with preexisting hepatic or biliary disease for adverse reactions.
  • Assess appetite, level of abdominal discomfort and extent of bloating.
  • Assess frequency and quantity of diarrhea and monitor total hydration status.
  • Weigh daily to aid in assessment of possible fluid loss from diarrhea.

Patient & Family Education

  • Note that 5 mL of the oral suspension contains approximately 1.5 g of sucrose.
  • Report either no improvement in or worsening of diarrhea and abdominal discomfort.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2023 Last Updated On: 01/27/2023 (0)
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