Quick answers
- What is Zileuton used for?
- The FDA-approved label (Zyflo, Chiesi USA, Inc., November 30, 2025) says: “ZYFLO is indicated for the prophylaxis and chronic treatment of asthma in adults and children 12 years of age and older.” This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
- Does Zileuton have a boxed warning?
- No. None of the 6 FDA labels we found for this medicine has a boxed warning.
- Is there a shortage of Zileuton?
- No current shortage is listed by the FDA for the products of this medicine (FDA data from October 30, 2026).
- Has Zileuton been recalled?
- No recall linked to the products of this medicine appears in the FDA enforcement reports we use.
- Who makes Zileuton?
- 6 companies list prescription products of Zileuton in the FDA NDC Directory, including NorthStar RxLLC, Strides Pharma Science Limited and Camber Pharmaceuticals, Inc..
What Zileuton is used for
Quoted from the “Indications and Usage” section of the FDA-approved label.
ZYFLO is indicated for the prophylaxis and chronic treatment of asthma in adults and children 12 years of age and older.
— FDA label: Zyflo, Chiesi USA, Inc., effective November 30, 2025. Read the full label on DailyMed →
The FDA has 6 labels for products of this medicine (different makers and forms); uses can differ between them. Check the label that comes with your own medicine.
This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
Conditions named on the label
These condition names appear word for word in the label’s “Indications and Usage” text (matched with a reviewed table). Each page lists hospitals whose own websites name the condition.
Related medical specialties
Boxed warning
A boxed warning (“black box”) is the FDA’s strongest warning on a drug label, for serious or life-threatening risks.
The label quoted above has no boxed warning.
0 of 6 FDA labels for this medicine have a boxed warning.
Forms and how it is given
| Dosage forms | Tablet, film coated, extended release · Tablet, multilayer, extended release · Tablet · Tablet, extended release |
|---|---|
| Route | Oral |
| Prescription products | 6 in the FDA NDC Directory |
| Brand names | Zyflo |
What pharmacies pay (NADAC)
The National Average Drug Acquisition Cost (NADAC) is the average price U.S. retail pharmacies paid to buy one unit of a medicine (one tablet, one mL or one gram), from a monthly survey of pharmacy invoices by the Centers for Medicare & Medicaid Services (CMS). State Medicaid programs use it to pay pharmacies.
This is not the price you pay. What you pay depends on your insurance (copay or coinsurance), your pharmacy and any discounts, and pharmacies also charge for filling a prescription. Ask your pharmacist or your health plan what your price will be.
| Strength and form | Generic or brand | Pharmacies pay |
|---|---|---|
| zileuton 600 mg tablet, extended release | Generic | $2.07 per tablet |
| zileuton 600 mg tablet, film coated, extended release | Generic | $2.07 per tablet |
| zileuton 600 mg tablet, multilayer, extended release | Generic | $2.07 per tablet |
NADAC list of November 4, 2026; these prices took effect on October 21, 2026. Shown only where a package’s NDC code matches the NADAC list exactly, and only for that exact strength and form: nothing is averaged across strengths. Strengths and forms not listed here have no NADAC price.
Source: NADAC (National Average Drug Acquisition Cost) 2026, data.medicaid.gov (CMS) →
Companies that list this medicine
Labelers in the FDA NDC Directory: the company named on the package (maker or distributor), with the number of prescription products.
- NorthStar RxLLC1 product
- Strides Pharma Science Limited1 product
- Camber Pharmaceuticals, Inc.1 product
- Chiesi USA, Inc.1 product
- Golden State Medical Supply, Inc.1 product
- Rising Pharma Holdings, Inc.1 product
FDA approval history
- NDA: New Drug Application: how a new (usually brand-name) medicine is approved.
- ANDA: Abbreviated New Drug Application: how a generic version is approved.
| Application | Sponsor | Approved | Later changes approved |
|---|---|---|---|
| NDA020471 ZYFLO | Chiesi | December 9, 1996 | 11, latest June 8, 2012 2012: Labeling · 2009: Labeling · 2005: Manufacturing (CMC) |
Generic approvals (3)
- ANDA204929Rising · March 17, 2017
- ANDA212670Strides Pharma Intl · December 16, 2019
- ANDA215742Annora Pharma · October 11, 2022
Shortage status
The FDA drug shortage list does not show these products.
Recalls
No recall linked to these products (by their NDC code) appears in the FDA enforcement reports.
Official identifiers
| RxCUI (RxNorm) | 199904, 211777, 730834 |
|---|---|
| SPL set ID of the quoted label | aee65202-fddb-497f-9f11-17cc727cb157 |
| FDA labels (SPL) | 6 |
| FDA applications | NDA020471, 3 ANDA |
| Active ingredients (FDA) | ZILEUTON |
Sources
- FDA-approved label on DailyMed (National Library of Medicine) — Zyflo, Chiesi USA, Inc., effective November 30, 2025; via openFDA, FDA data exported October 30, 2026, retrieved October 31, 2026
- NDC Directory (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
- Drugs@FDA (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
- Drug recall enforcement reports (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 27, 2026, retrieved October 31, 2026
- Drug shortages (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
openFDA data is provided by the FDA as is; it may be incomplete. Always rely on the label that comes with your medicine. FDA Enforcement Report search →