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.
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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.
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
- Death
Death
81 reports
- Pathogen Resistance
Pathogen Resistance
54 reports
- Drug Resistance 30
Drug Resistance
30 reports
- Acute Kidney Injury 29
Acute Kidney Injury
29 reports
- Incorrect Dose Administered 26
Incorrect Dose Administered
26 reports
- Pneumonia 26
Pneumonia
26 reports
- Pancytopenia 25
Pancytopenia
25 reports
- Septic Shock 24
Septic Shock
24 reports
- Thrombocytopenia 24
Thrombocytopenia
24 reports
- Encephalopathy 23
Encephalopathy
23 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.
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?
Can Zerbaxa cause an allergic reaction?
How long will I need to take Zerbaxa?
What if I have kidney problems?
Can Zerbaxa cause diarrhea?
Is Zerbaxa safe to use during pregnancy?
Can I breastfeed while taking Zerbaxa?
What are the common side effects of Zerbaxa?
How is Zerbaxa given?
What does Zerbaxa contain?
What are the common side effects of ceftolozane/tazobactam?
What drug class is ceftolozane/tazobactam?
What pregnancy or breastfeeding source fields are listed for ceftolozane/tazobactam?
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.
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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.
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ampicillin/sulbactam
Unasyn
Unasyn is a combination of two antibiotics that fights bacteria in your body.
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azithromycin
Zithromax, Z-Pack
Azithromycin is an antibiotic that fights bacteria.
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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 are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
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. This registry does not provide medication decisions.
Last updated: November 4, 2024
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
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 from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages