Indication	First Choice	Alternative	Comments/Special Issues
Primary Prophylaxis	cART to avoid advanced immunodeficiency	N/A	N/A
Secondary Prophylaxis	N/A	N/A	N/A
Treatment	Tinidazole, 50 mg/kg by mouth, administered as 1 dose given with food (maximum 2 g). Note: Based on data from HIV-uninfected children Nitazoxanide. Note: Based on data from HIV-uninfected children 1–3 years: 100 mg by mouth every 12 hours with food for 3 days 4–11 years: 200 mg by mouth every 12 hours with food for 3 days ≥12 years: 500 mg by mouth every 12 hours with food for 3 days	Metronidazole 5 mg/kg by mouth every 8 hours for 5-7 days. Note: Based on data from HIV-uninfected children	Tinidazole is approved in the United States for children aged ≥3 years. It is available in tablets that can be crushed. Metronidazole has high frequency of gastrointestinal side effects. A pediatric suspension of metronidazole is not commercially available but can be compounded from tablets. It is not FDA-approved for the treatment of giardiasis. Supportive Care: Hydration Correction of electrolyte abnormalities Nutritional support Antimotility agents (e.g., loperamide) should be used with caution in young children.

Key to Abbreviations: cART = combination antiretroviral therapy; FDA = U.S. Food and Drug Administration