Nitazoxanide
Nitazoxanide is an antiprotozoal (anti-parasite) medicine used to treat diarrhea caused by two intestinal parasites, Giardia lamblia and Cryptosporidium parvum.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 4 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Nitazoxanide is an antiprotozoal (anti-parasite) medicine for diarrhea caused by Giardia or Cryptosporidium, thought to block an enzyme these parasites need to make energy without oxygen; on the market since about 2002 and available as a generic, it is a common alternative for Giardia and the go-to prescription for Cryptosporidium. Most people tolerate it well, with mild belly pain, nausea or headache, and urine can turn darker or discolored. Get medical help for a rash, hives or trouble breathing, which can signal an allergic reaction. It has not been shown to work against Cryptosporidium in people with HIV or a weakened immune system.
Clinical pearls
- Take every dose with food, and finish the full short course even if the diarrhea settles early.
- If you take warfarin, mention it before starting, since nitazoxanide can compete with warfarin in the blood and closer watching may be needed.
- Tablets are only for ages 12 and older; children 1 to 11 use the oral suspension, the form studied in them.
- If diarrhea keeps going or worsens after the course, get rechecked rather than repeating the medicine on your own.
Patient information guide A plain-language walkthrough of Nitazoxanide, written from its FDA label.
What Nitazoxanide is used for
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Nitazoxanide treats diarrhea caused by certain intestinal parasites.
- Diarrhea caused by Giardia lamblia
- Diarrhea caused by Cryptosporidium parvum
- Nitazoxanide tablets are for patients 12 years and older.
- Alinia oral suspension is studied in children 1 to 11 years and in those 12 to 17 years.
- It has not been shown to work for Cryptosporidium diarrhea in people with HIV or weakened immune systems.
How Nitazoxanide works
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Nitazoxanide is an antiprotozoal medicine. It is believed to block an enzyme called PFOR, which these parasites need for energy production without oxygen. The body quickly turns nitazoxanide into its active form, tizoxanide.
It may also work in other ways. Whether the parasites can become resistant has not been examined.
Nitazoxanide dosage
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Nitazoxanide is taken by mouth with food. Tablets are taken about every 12 hours for 3 days in patients 12 years and older.
- Tablets are not for children 11 years or younger.
- Alinia oral suspension is another form and is not bioequivalent to the tablets.
- Follow your prescriber and the label for exact directions.
Dosing details from the FDA-approved label
From the Nitazoxanide prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Diarrhea caused by G. lamblia or C. parvum, patients 12 years and older
- One nitazoxanide tablet (500 mg nitazoxanide) taken orally every 12 hours with food for 3 days
- Take with food
- Pediatric patients 11 years of age or younger
- Nitazoxanide tablets should not be administered to pediatric patients 11 years of age or younger
- A single tablet contains a greater amount of nitazoxanide than the recommended dosing in this pediatric age group
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION • Nitazoxanide tablets should not be administered to pediatric patient 11 years of age or younger (2.1). • Dosage for treatment of diarrhea caused by G. lamblia or C. parvum (2.1) : Age Dosage Duration 12 years and older One nitazoxanide tablet (500 mg nitazoxanide) every 12 hours with food 3 days 2.1 Recommended Dosage and Important Administration Instructions Important Administration Instructions for Pediatric Patients 11 years of Age or Younger: Nitazoxanide tablets should not be administered to pediatric patients 11 years of age or younger because a single tablet contains a greater amount of nitazoxanide than the recommended dosing in this pediatric age group. Table 1. Recommended Dosage Age Dosage Duration 12 years and older One Nitazoxanide tablet (500 mg nitazoxanide) taken orally every 12 hours with food 3 days
Read the full Dosage and Administration section on DailyMed →
Nitazoxanide side effects
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The most common side effects in clinical trials were:
Common side effects
- Abdominal pain
- Headache
- Chromaturia (darker or discolored urine)
- Nausea
When to get medical help
- Call your doctor if you develop a rash or hives, which have been reported after approval.
- Get medical help if you have trouble breathing (shortness of breath).
- Tell your doctor if you feel dizzy, or if your diarrhea or reflux symptoms continue or get worse.
- Seek urgent care for signs of an allergic reaction, since the medicine must not be used by anyone allergic to it.
Nitazoxanide warnings and precautions
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- Do not use it if you are allergic to nitazoxanide or any ingredient.
- Tablets should not be given to children 11 years or younger.
- It has not been shown to work for Cryptosporidium diarrhea in people with HIV or weakened immune systems.
- It has not been studied in people with kidney or liver problems.
Nitazoxanide interactions
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Nitazoxanide's active form binds very tightly to proteins in the blood.
- Warfarin and similar drugs: these also bind tightly to blood proteins and have a narrow safety margin, so they may compete and side effects should be watched for.
Interactions listed in the FDA-approved label
From the Nitazoxanide prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Other highly plasma protein-bound drugs with narrow therapeutic indices (e.g., warfarin): Tizoxanide, the active metabolite of nitazoxanide, is highly bound to plasma protein (>99.9%), so competition for binding sites may occur. Monitor for adverse reactions when administering nitazoxanide concurrently with these drugs.
Read the label’s full interactions text
7 DRUG INTERACTIONS Competition for binding sites may occur when administered concurrently with other highly plasma protein-bound drugs with narrow therapeutic indices. Monitor for adverse reactions ( 7 ). 7.1 Highly Protein Bound Drugs with Narrow Therapeutic Indices Tizoxanide (the active metabolite of nitazoxanide) is highly bound to plasma protein (>99.9%). Therefore, monitor for adverse reactions when administering nitazoxanide concurrently with other highly plasma protein-bound drugs with narrow therapeutic indices, as competition for binding sites may occur (e.g., warfarin).
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Nitazoxanide
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- Tell your prescriber about any past allergy to nitazoxanide.
- Pregnancy: there are no human data. Animal studies showed no birth defects or harm to the fetus.
- Breastfeeding: it is not known if the drug passes into milk or affects the baby.
- Older adults: studies had too few people 65 and over to know if they respond differently.
- Kidney or liver problems: the drug has not been studied in these groups.
Nitazoxanide overdose
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Information on overdose is limited. There is no specific antidote. Doctors may consider stomach pumping soon after a dose, and will observe you and give supportive treatment. Dialysis is unlikely to help much.
What Nitazoxanide does in the body
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Nitazoxanide and its active form, tizoxanide, stop the growth of Cryptosporidium parvum and Giardia lamblia in lab tests. It is believed to interfere with an enzyme these parasites need for energy.
How your body processes Nitazoxanide
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After you swallow it, nitazoxanide itself is not found in the blood. It is quickly converted to the active tizoxanide, which is then mostly attached to glucuronic acid for removal. Food raises the amount of medicine absorbed, which is why it is taken with food.
About two-thirds of a dose leaves in the stool and one-third in the urine. Levels did not build up significantly over 7 days of tablets every 12 hours.
How to store Nitazoxanide
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Store the tablets at 20º to 25ºC (68º to 77ºF); excursions permitted to 15° to 30°C (59° to 86°F) .
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Nitazoxanide
17 supplements and herbal products have documented interactions with Nitazoxanide in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 7
- Minor · 9
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nitazoxanide: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Nitazoxanide — the kind of thing our pharmacy team would talk through with you at the counter.
What is this medicine for?
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How should I take it?
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What side effects should I expect?
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Can I take it with my other medicines?
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Can my child take the tablets?
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Is it safe in pregnancy or while breastfeeding?
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Is Nitazoxanide available over the counter?
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When was Nitazoxanide first available?
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Who makes Nitazoxanide?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Nitazoxanide on HelloPharmacist
Nitazoxanide forms and strengths (how it comes)
Nitazoxanide is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Nitazoxanide inactive ingredients by manufacturer.
Tablet
How this form is used
- Nitazoxanide tablets are used for diarrhea caused by Giardia lamblia or Cryptosporidium parvum in patients 12 years and older.
- Nitazoxanide tablets are taken by mouth about every 12 hours with food for 3 days.
- Nitazoxanide tablets should not be given to children 11 years or younger.
Nitazoxanide on the U.S. market: products, makers and brands
How Nitazoxanide appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
4 companies list 4 Nitazoxanide product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 2002. Brand names on the directory include Alinia; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (9) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
How widely Nitazoxanide is used (Medicaid data)
A general measure of how commonly Nitazoxanide is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Nitazoxanide is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Nitazoxanide prescribed? Of the 1,601 medications we measure, Nitazoxanide ranks #1,390 by Medicaid prescriptions — more than 13% of them.
Utilization by Nitazoxanide product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
nitazoxanide 500 MG Oral Tablet
Summed across the 2 of 13 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 427163
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Nitazoxanide, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 2 of 13 listed Nitazoxanide NDCs with Medicaid activity.
Compare Nitazoxanide products
A representative set of FDA-listed product records for Nitazoxanide — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 500 mg | Oral | ANI Pharmaceuticals, Inc. | ANDA | View NDC → |
| 500 mg | Oral | Camber Pharmaceuticals, Inc. | ANDA | View NDC → |
| 500 mg | Oral | e5 Pharma, LLC | ANDA | View NDC → |
| 500 mg | Oral | Rising Pharma Holdings, Inc. | ANDA | View NDC → |
Showing 4 of 4 products — FDA National Drug Code Directory. See every product, package size and price: browse all 4 Nitazoxanide NDCs →
Nitazoxanide side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Nitazoxanide — a signal of what to watch for, not proof the drug caused it.
The effects most often named in FDA reports that mention Nitazoxanide are diarrhoea, disease progression, dyspnoea; about 92% of the reports were classed as serious. These are voluntary reports, so they show what people report, not how often it happens.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Nitazoxanide in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Nitazoxanide FDA approval history
How Nitazoxanide went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Nitazoxanide was first approved by the FDA in 2002 (Brand: ALINIA · Romark); the first generic version was approved in 2020. It remains available in U.S. pharmacies today.
Source: Drugs@FDA.
Nitazoxanide recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Nitazoxanide recalls since July 2021.
✅No Nitazoxanide recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 31819 3 dose forms · 3 strengths
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Dose form (SCDF) Oral Solution RxCUI 378732No current FDA listingClinical drug / strength (SCD) 20 MG/MLRxCUI 351280 -
Dose form (SCDF) Oral Suspension RxCUI 378307No current FDA listingClinical drug / strength (SCD) 20 MG/MLRxCUI 359822 -
Dose form (SCDF) Oral Tablet RxCUI 446753In current FDA listingsClinical drug / strength (SCD) 500 MGRxCUI 427163
Look up RxCUI 31819 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Nitazoxanide supply and shortage status
Whether Nitazoxanide is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
💵 What Nitazoxanide costs pharmacies (NADAC benchmark)
The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.
| Form | Strength | Pharmacy acquisition benchmark | |
|---|---|---|---|
| Tablet, Film Coated · Oral | 500 mg | $82.20 per tablet | NDC details & price history |
Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.
Nitazoxanide brand names
Nitazoxanide is sold under one brand name in the FDA directory — Alinia. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Nitazoxanide: manufacturers and labelers
4 companies list Nitazoxanide products with the FDA. By number of product records, the largest are ANI Pharmaceuticals, Inc., Camber Pharmaceuticals, Inc., Rising Pharma Holdings, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Nitazoxanide drug class (RxNorm)
Nitazoxanide belongs to the Antiprotozoal class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Nitazoxanide page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. ANI Pharmaceuticals, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →