Unasyn

Treats infections due to susceptible strains of the designated microorganisms in the…. NDA 50608, held by Pfizer. Ampicillin Sodium; Sulbactam Sodium.

As of Nov 14, 2026, NDA 50608 (Unasyn), held by Pfizer, was first approved by FDA on Dec 31, 1986, with 29 approved supplements and 0 published complete response letters.

First approved: Dec 31, 1986
Review: Standard
Supplements approved: 29
Complete response letters: 0

What It's For

From the FDA-approved label (Indications and Usage)

INDICATIONS AND USAGE UNASYN is indicated for the treatment of infections due to susceptible strains of the designated microorganisms in the conditions listed below. Skin and Skin Structure Infections caused by beta-lactamase producing strains of Staphylococcus aureus, Escherichia coli, Efficacy for this organism in this organ system was studied in fewer than 10 infections. Klebsiella spp. (including K. pneumoniae ), Proteus mirabilis, Bacteroides fragilis, Enterobacter spp., and Acinetobacter calcoaceticus. NOTE: For information on use in pediatric patients (see PRECAUTIONS-Pediatric Use and CLINICAL STUDIES sections).

Full prescribing information on DailyMed ↗

Approvals and New Uses

The original application and every efficacy supplement, newest first; all 30 submissions below


Feb 12, 1997	Supplement 19Efficacy (new indication or use) · Standard review	Approved	Review
Dec 31, 1986	Original applicationNew molecular entity, new combination · Standard review	Approved	Review

Products

4 strengths and forms


UnasynEQ 2GM BASE/VIAL;EQ 1GM BASE/VIAL · injectable;injection	Ampicillin Sodium; Sulbactam Sodium	RxReference drug
UnasynEQ 1GM BASE/VIAL;EQ 500MG BASE/VIAL · injectable;injection	Ampicillin Sodium; Sulbactam Sodium	RxReference drug
UnasynEQ 500MG BASE/VIAL;EQ 250MG BASE/VIAL · injectable;injection	Ampicillin Sodium; Sulbactam Sodium	Discontinued
UnasynEQ 10GM BASE/VIAL;EQ 5GM BASE/VIAL · injectable;injection	Ampicillin Sodium; Sulbactam Sodium	RxReference drug

All 30 submissions, including labeling and manufacturing supplements


Nov 5, 2025	Supplement 58Labeling · Standard review	Approved	Label Letter
Jan 31, 2025	Supplement 56Labeling · Standard review	Approved	Letter Label
May 1, 2024	Supplement 53Labeling · Standard review	Approved	Label Letter
Oct 9, 2020	Supplement 47Labeling · Standard review	Approved	Letter Label
Apr 19, 2018	Supplement 46Labeling · Standard review	Approved	Letter Label
Feb 13, 2017	Supplement 44Labeling · Standard review	Approved	Label Letter
Feb 9, 2015	Supplement 43Manufacturing · Standard review	Approved	None posted
Nov 17, 2014	Supplement 42Labeling · Standard review	Approved	Label Letter
Nov 17, 2014	Supplement 41Labeling · Standard review	Approved	Label Letter
Dec 14, 2012	Supplement 38Manufacturing · Standard review	Approved	None posted
Mar 6, 2012	Supplement 40Labeling · Standard review	Approved	Letter Label
Apr 14, 2008	Supplement 29Labeling · Standard review	Approved	Label Letter
Aug 19, 2004	Supplement 26Labeling · Standard review	Approved	Letter
Mar 13, 2002	Supplement 25Manufacturing · Standard review	Approved	None posted
Feb 14, 2001	Supplement 24Manufacturing · Standard review	Approved	None posted
May 29, 1998	Supplement 23Manufacturing · Standard review	Approved	None posted
Feb 12, 1997	Supplement 19Efficacy (new indication or use) · Standard review	Approved	Review
Dec 6, 1996	Supplement 21Manufacturing · Standard review	Approved	None posted
May 15, 1996	Supplement 20Manufacturing · Standard review	Approved	None posted
Dec 10, 1993	Supplement 18Manufacturing · Standard review	Approved	None posted
Nov 5, 1993	Supplement 17Labeling · Standard review	Approved	None posted
Mar 24, 1993	Supplement 15Manufacturing · Standard review	Approved	None posted
Oct 8, 1992	Supplement 16Labeling	Approved	None posted
May 8, 1992	Supplement 14Manufacturing · Standard review	Approved	None posted
Apr 23, 1992	Supplement 13Manufacturing · Standard review	Approved	None posted
Mar 27, 1992	Supplement 11Labeling	Approved	None posted
Jan 2, 1992	Supplement 12Manufacturing · Standard review	Approved	None posted
Nov 22, 1991	Supplement 9Manufacturing · Standard review	Approved	None posted
Aug 3, 1989	Supplement 7Manufacturing · Standard review	Approved	None posted
Dec 31, 1986	Original applicationNew molecular entity, new combination · Standard review	Approved	Review

Identifiers

Application: NDA 50608
Drugs@FDA: Overview at FDA
Company: Pfizer

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