PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Prescription medication · Cephalosporin / Beta-Lactamase Inhibitor

ceftolozane/tazobactam

Also sold as Zerbaxa. Zerbaxa treats complicated infections in the stomach area and urinary tract.

Data updated 2026-05-15

342
FDA reports
Rx
Availability

ceftolozane/tazobactam (Zerbaxa) is a prescription Cephalosporin / Beta-Lactamase Inhibitor. Zerbaxa treats complicated infections in the stomach area and urinary tract.

Zerbaxa is a combination of two antibiotics, ceftolozane and tazobactam. It fights bacterial infections in your body.

Verify with FDA → · CMS NADAC pricing →

View Alternatives → Compare with Another Drug →

What it does

Zerbaxa treats complicated infections in the stomach area and urinary tract.

Common side effects

Nausea, Diarrhea, Headache

Key warnings

Zerbaxa may not work as well if your kidneys aren't working well.

The sections below are summarized in plain English from ceftolozane/tazobactam's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Ceftolozane kills bacteria by stopping them from building cell walls. Tazobactam helps ceftolozane work better by blocking the bacteria's defense mechanisms. This allows ceftolozane to effectively kill the bacteria.

How to Take It

Zerbaxa is given through a vein (IV) every 8 hours. Each dose is infused slowly over 1 hour. Your doctor will decide the right dose and how long you need treatment. The typical treatment lasts 4 to 14 days, depending on the infection.

This is a plain-language summary of ceftolozane/tazobactam's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.

Pregnancy & Breastfeeding

It is not known if Zerbaxa will harm an unborn baby. Talk to your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

This is a plain-language summary of ceftolozane/tazobactam's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.

Missed Dose

If you miss a dose, contact your doctor as soon as possible to reschedule it.

This is a plain-language summary of ceftolozane/tazobactam's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.

Storage

Keep Zerbaxa vials refrigerated at 36 to 46°F (2 to 8°C) and away from light.

Side Effects (from patient reports)

Based on 342 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for ceftolozane/tazobactam, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS)

Serious Warnings

Zerbaxa may not work as well if your kidneys aren't working well. Your doctor should check your kidney function daily and adjust your dose if needed. Zerbaxa can also cause severe allergic reactions. Tell your doctor if you are allergic to any beta-lactam antibiotics. Diarrhea can occur with Zerbaxa, even months after you stop taking it. Tell your doctor right away if you have diarrhea.

Common Questions

What should I tell my doctor before taking Zerbaxa?
Tell your doctor if you are allergic to any antibiotics, especially penicillins or cephalosporins. Also, tell them if you have kidney problems or diarrhea.
Can Zerbaxa cause an allergic reaction?
Yes, Zerbaxa can cause serious allergic reactions. Get medical help right away if you have hives, trouble breathing, or swelling of your face, lips, tongue, or throat.
How long will I need to take Zerbaxa?
The length of treatment depends on the type and severity of your infection. Your doctor will decide how long you need to take Zerbaxa, usually for 4 to 14 days.
What if I have kidney problems?
Your doctor will adjust the dose of Zerbaxa if you have kidney problems. They will also monitor your kidney function regularly.
Can Zerbaxa cause diarrhea?
Yes, Zerbaxa can cause diarrhea, even severe diarrhea caused by Clostridioides difficile. Tell your doctor right away if you have diarrhea while taking Zerbaxa or even after you stop taking it.
Is Zerbaxa safe to use during pregnancy?
It is not known if Zerbaxa is safe to use during pregnancy. Talk to your doctor if you are pregnant or planning to become pregnant.
Can I breastfeed while taking Zerbaxa?
Talk to your doctor if you are breastfeeding or planning to breastfeed while taking Zerbaxa.
What are the common side effects of Zerbaxa?
The most common side effects are nausea, diarrhea, headache, and fever.
How is Zerbaxa given?
Zerbaxa is given through a vein (IV) by a healthcare professional.
What does Zerbaxa contain?
Zerbaxa contains ceftolozane and tazobactam as active ingredients. It also contains sodium chloride, citric acid, and L-arginine.
What are the common side effects of ceftolozane/tazobactam?
The most commonly reported side effects of ceftolozane/tazobactam include Nausea, Diarrhea, Headache, Fever, Increased liver enzymes. Based on 342 FDA adverse event reports. Always consult your healthcare provider about potential side effects.
What drug class is ceftolozane/tazobactam?
ceftolozane/tazobactam belongs to the Cephalosporin / Beta-Lactamase Inhibitor drug class. It requires a prescription (Rx). Zerbaxa treats complicated infections in the stomach area and urinary tract.
Is ceftolozane/tazobactam safe during pregnancy?
It is not known if Zerbaxa will harm an unborn baby. Talk to your doctor if you are pregnant, planning to become pregnant, or breastfeeding. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.

Related Medications in Cephalosporin / Beta-Lactamase Inhibitor

Other drugs grouped near ceftolozane/tazobactam - same-class peers and common alternatives.

amikacin

Amikin

Amikacin is an antibiotic medicine.

Compare with ceftolozane/tazobactam →

amoxicillin

Amoxil

Amoxicillin and Clavulanate Potassium is a combination medicine used to fight bacterial infections.

Compare with ceftolozane/tazobactam →

amoxicillin/clavulanate

Augmentin

Augmentin is a combination of two medicines, amoxicillin and clavulanate.

Compare with ceftolozane/tazobactam →

ampicillin/sulbactam

Unasyn

Unasyn is a combination of two antibiotics that fights bacteria in your body.

Compare with ceftolozane/tazobactam →

azithromycin

Zithromax, Z-Pack

Azithromycin is an antibiotic that fights bacteria.

Compare with ceftolozane/tazobactam →

Compare ceftolozane/tazobactam vs amikacin side-by-side →

Medication Guides

Understanding Drug Interactions

How CYP450 enzymes, inhibitors, and inducers affect your medications

Generic vs Brand Name Drugs

FDA requirements, cost savings, and when the difference matters

Narrow Therapeutic Index Drugs

Why some drugs demand precise dosing and monitoring

Common Drug Interactions

Dangerous medication combinations and how to protect yourself

Save on ceftolozane/tazobactam

Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.

Check Prices on GoodRx →

Disclosure: This link may earn us a commission at no extra cost to you. See our terms.

What the FDA Data Shows for ceftolozane/tazobactam

The FDA label for ceftolozane/tazobactam (sold under brand names such as Zerbaxa) classifies it as a prescription-only medication in the Cephalosporin / Beta-Lactamase Inhibitor class. Zerbaxa treats complicated infections in the stomach area and urinary tract. Official labeling lists 11 commonly reported side effects, including Nausea, Diarrhea, Headache.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 342 voluntary reports. Interaction data is drawn directly from FDA-approved prescribing information. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: November 4, 2024

Read our methodology - how this data is sourced, computed, and verified.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.

All federal data sources used on this page