What Is Nitazoxanide? Uses, Dosage, and What You Need to Know in 2026

Nitazoxanide is an antiparasitic and antiviral prescription medication used to treat diarrhea caused by intestinal parasites. It belongs to a drug class called thiazolides and was originally discovered in the 1980s at the Pasteur Institute in France. In the United States, it is sold under the brand name Alinia, with generic tablets available since 2020. Here is a comprehensive overview of what nitazoxanide is, what it treats, how it's taken, and what to expect.

What Is Nitazoxanide (Alinia) Used For?

The FDA has approved nitazoxanide specifically for two indications in immunocompetent (non-immunocompromised) patients:

1. Giardiasis (Giardia lamblia infection): A parasitic infection of the small intestine causing diarrhea, bloating, gas, and greasy stools. Giardia is commonly acquired through contaminated water, hiking, or international travel. Nitazoxanide is approved for adults and children 1 year and older.
2. Cryptosporidiosis (Cryptosporidium parvum infection): A waterborne parasitic infection causing watery diarrhea. Nitazoxanide is one of the few effective treatments for this infection in immunocompetent individuals. Note: It has NOT been shown effective for Cryptosporidium in HIV-infected or immunodeficient patients.

Off-Label Uses of Nitazoxanide

Beyond its FDA-approved indications, nitazoxanide is used off-label by clinicians for several other infections:

• Clostridioides difficile (C. diff) colitis — used in combination with other agents
• Blastocystis species infections
• Entamoeba histolytica (intestinal amebiasis)
• Hymenolepis nana (dwarf tapeworm) and other helminthic infections
• Influenza — nitazoxanide reached Phase 3 clinical trials for influenza treatment due to its broad antiviral activity

Nitazoxanide Dosage: Adults and Children

Nitazoxanide is taken orally twice daily for 3 days (6 total doses). The specific dose depends on age:

• Adults and adolescents 12 years and older: One 500 mg tablet every 12 hours for 3 days, with food
• Children ages 4-11 years: 10 mL (200 mg) of oral suspension every 12 hours for 3 days, with food
• Children ages 1-3 years: 5 mL (100 mg) of oral suspension every 12 hours for 3 days, with food

Critical: always take with food. Taking nitazoxanide with a meal nearly doubles the amount of active drug absorbed into the bloodstream. Taking it on an empty stomach significantly reduces efficacy.

Dosage Forms Available

Nitazoxanide is available in two forms in the United States:

• Tablets: 500 mg — for patients 12 years and older; generic available since 2020
• Oral suspension: 100 mg/5 mL — strawberry-flavored liquid for children 1-11 years; brand Alinia only (no generic available); must be discarded 7 days after reconstitution

Is Nitazoxanide a Controlled Substance?

No. Nitazoxanide is not a controlled substance and is not scheduled by the DEA. It requires a prescription but has no special prescribing restrictions beyond a valid patient-provider relationship.

Who Should Not Take Nitazoxanide?

The only absolute contraindication is a known hypersensitivity (allergic reaction) to nitazoxanide or any of the inactive ingredients in the formulation. Use with caution in patients with significant liver or kidney disease. Not approved for immunocompromised patients for C. parvum treatment.

For a detailed look at side effects, see our guide: Nitazoxanide Side Effects: What to Expect. Once you have your prescription, medfinder can help you find a pharmacy with it in stock.