Zyflo

Treats asthma. NDA 20471, held by Chiesi. Zileuton.

As of Nov 14, 2026, NDA 20471 (Zyflo), held by Chiesi, was first approved by FDA on Dec 9, 1996, with 11 approved supplements and 0 published complete response letters.

First approved: Dec 9, 1996
Review: Standard
Supplements approved: 11
Complete response letters: 0

What It's For

From the FDA-approved label (Indications and Usage)

INDICATIONS AND USAGE ZYFLO is indicated for the prophylaxis and chronic treatment of asthma in adults and children 12 years of age and older.

Full prescribing information on DailyMed ↗

Approvals and New Uses

The original application and every efficacy supplement, newest first; all 12 submissions below

Date	Submission	Status	Documents
Dec 9, 1996	Original applicationNew molecular entity · Standard review	Approved	Review

Products

2 strengths and forms


Zyflo300MG · tablet;oral	Zileuton	DiscontinuedReference drug
Zyflo600MG · tablet;oral	Zileuton	DiscontinuedReference drug

All 12 submissions, including labeling and manufacturing supplements


Jun 8, 2012	Supplement 17Labeling	Approved	Label Letter
Aug 21, 2009	Supplement 14Labeling · Standard review	Approved	Letter Label
Sep 28, 2005	Supplement 11Manufacturing · Standard review	Approved	Letter Label
Dec 16, 2002	Supplement 9Labeling · Standard review	Approved	Review Letter
Apr 23, 2001	Supplement 8Labeling · Standard review	Approved	None posted
Sep 24, 1998	Supplement 6Manufacturing · Standard review	Approved	None posted
Sep 4, 1998	Supplement 7Labeling · Standard review	Approved	Review
Sep 8, 1997	Supplement 5Manufacturing · Standard review	Approved	None posted
May 30, 1997	Supplement 3Manufacturing · Standard review	Approved	None posted
May 21, 1997	Supplement 1Manufacturing · Standard review	Approved	None posted
May 6, 1997	Supplement 4Manufacturing · Standard review	Approved	None posted
Dec 9, 1996	Original applicationNew molecular entity · Standard review	Approved	Review

Identifiers

Application: NDA 20471
Drugs@FDA: Overview at FDA
Company: Chiesi

Approvals, supplements, products and documents come from FDA's Drugs@FDA data files, refreshed daily; Drugs@FDA lists approved applications only. Complete response letters are FDA's published letters. Drugs@FDA and FDA complete response letters