Drug · FAERS side-effect profile with label screen
Tazobactam and Piperacillin side effects: what 6,719 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Tazobactam Sodium And Piperacillin Sodium (Zosyn In Galaxy Containers)
closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match
Who reports
6,719 reports · 89% serious · 1,655 with death outcome · 44% female
openFDA FAERS counts, all years, deduplication not applied
Used for
ZOSYN is a combination of piperacillin, a penicillin-class antibacterial and tazobactam, a beta-lactamase inhibitor, indicated for the treatment of: • Intra-abdominal infections in adult and pediatric patients 2 months of age and older ( 1.1 ) • Nosoco.
FDA label, Indications and Usage
What it is
ZOSYN (piperacillin and tazobactam) Injection is an injectable antibacterial combination product consisting of the semisynthetic antibacterial piperacillin sodium and the beta-lactamase inhibitor tazobactam sodium for intravenous administration. Piperacillin sodium is derived from D(-)-α-aminobenzyl-penicillin.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 6Labeled (related wording) 6Likely indication confounding 2Lab value / disease marker 3Not in label — unassessed 23
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 409 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Renal tubular necrosis | 94 | 30.1 24.6–36.8ROR 30.5 · χ² 2,593 / p <1e-300 | 29.7 EB05 25.0 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious PRR 18.9 · 94% clinician | no trial data cached |
| Disseminated intravascular coagulation | 126 | 28.1 23.6–33.4ROR 28.6 · χ² 3,238 / p <1e-300 | 27.7 EB05 23.9 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious PRR 18.0 · 90% clinician | no trial data cached |
| Multi-organ failure | 103 | 18.4 15.2–22.3ROR 18.7 · χ² 1,672 / p <1e-300 | 18.3 EB05 15.5 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 11.6 | no trial data cached |
| Acute respiratory failure | 108 | 17.7 14.7–21.4ROR 18.0 · χ² 1,677 / p <1e-300 | 17.6 EB05 14.9 · IC025 +3.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 11.4 | no trial data cached |
| Tubulointerstitial nephritis | 101 | 16.9 13.9–20.5ROR 17.2 · χ² 1,490 / p <1e-300 | 16.8 EB05 14.2 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 10.7 · 100% clinician | no trial data cached |
| Atelectasis | 52 | 16.8 12.8–22.1ROR 16.9 · χ² 754 / p 2e-166 | 16.6 EB05 13.1 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 10.9 | no trial data cached |
| Renal failure acute | 219 | 16.0 14.0–18.2ROR 16.5 · χ² 3,046 / p <1e-300 | 15.9 EB05 14.2 · IC025 +3.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 9.8 | no trial data cached |
| Nephropathy toxic | 53 | 14.9 11.4–19.5ROR 15.0 · χ² 672 / p 2e-148 | 14.7 EB05 11.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 · 94% clinician | no trial data cached |
| Clostridium difficile colitis | 48 | 14.2 10.7–18.8ROR 14.3 · χ² 572 / p 1e-126 | 13.9 EB05 10.8 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 9.3 | no trial data cached |
| Leukocytosis | 80 | 13.9 11.1–17.2ROR 14.0 · χ² 939 / p 2e-206 | 13.7 EB05 11.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 | no trial data cached |
| Septic shock | 184 | 13.3 11.6–15.4ROR 13.7 · χ² 2,084 / p <1e-300 | 13.2 EB05 11.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 | no trial data cached |
| Sepsis (blood infection) | 458 | 12.9 11.8–14.1ROR 13.7 · χ² 5,003 / p <1e-300 | 12.8 EB05 11.8 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 8.3 | no trial data cached |
| Bacteraemia | 48 | 12.8 9.6–16.9ROR 12.9 · χ² 508 / p 1e-112 | 12.5 EB05 9.6 · IC025 +3.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 7.9 | no trial data cached |
| Acute respiratory distress syndrome | 72 | 12.8 10.1–16.1ROR 12.9 · χ² 765 / p 9e-169 | 12.5 EB05 10.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 | no trial data cached |
| Toxic epidermal necrolysis (severe skin peeling reaction) | 59 | 12.3 9.5–15.8ROR 12.4 · χ² 597 / p 4e-132 | 12.0 EB05 9.5 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.6 | no trial data cached |
| Febrile neutropenia | 259 | 12.3 10.9–13.8ROR 12.7 · χ² 2,663 / p <1e-300 | 12.2 EB05 11.0 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.9 · 92% clinician | no trial data cached |
| Mental status changes | 103 | 11.6 9.6–14.1ROR 11.8 · χ² 985 / p 1e-216 | 11.4 EB05 9.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 | no trial data cached |
| Cytokine release syndrome | 69 | 11.3 9.0–14.3ROR 11.4 · χ² 639 / p 4e-141 | 11.1 EB05 9.0 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 7.4 · 91% clinician | no trial data cached |
| Pneumonia aspiration | 90 | 11.3 9.2–13.9ROR 11.4 · χ² 833 / p 1e-183 | 11.1 EB05 9.2 · IC025 +3.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 7.2 | no trial data cached |
| Hepatic function abnormal | 131 | 11.1 9.3–13.1ROR 11.3 · χ² 1,187 / p 2e-260 | 10.9 EB05 9.4 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.4 | no trial data cached |
| End stage renal disease | 65 | 11.0 8.7–14.1ROR 11.1 · χ² 583 / p 5e-129 | 10.8 EB05 8.6 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Hypoxia (low oxygen) | 123 | 11.0 9.2–13.1ROR 11.2 · χ² 1,104 / p 2e-242 | 10.8 EB05 9.3 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Respiratory failure | 254 | 10.9 9.7–12.3ROR 11.3 · χ² 2,273 / p <1e-300 | 10.8 EB05 9.7 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.9 | no trial data cached |
| Cholecystitis | 41 | 10.8 8.0–14.7ROR 10.9 · χ² 354 / p 3e-79 | 10.3 EB05 7.8 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 | no trial data cached |
| Blood urea increased | 58 | 10.8 8.3–13.9ROR 10.9 · χ² 504 / p 7e-112 | 10.5 EB05 8.3 · IC025 +2.9 3/3 methods agree | Lab value / disease marker | serious PRR 7.7 | no trial data cached |
| Thrombotic microangiopathy | 33 | 10.7 7.6–15.0ROR 10.7 · χ² 279 / p 7e-63 | 10.1 EB05 7.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Dialysis | 46 | 10.1 7.6–13.5ROR 10.2 · χ² 368 / p 2e-82 | 9.7 EB05 7.4 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Blood alkaline phosphatase increased | 75 | 9.4 7.5–11.8ROR 9.5 · χ² 556 / p 3e-123 | 9.1 EB05 7.5 · IC025 +2.8 3/3 methods agree | Lab value / disease marker | serious PRR 6.2 | no trial data cached |
| Drug eruption | 53 | 9.4 7.2–12.3ROR 9.5 · χ² 389 / p 6e-87 | 9.0 EB05 7.1 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 · 94% clinician | no trial data cached |
| Pancytopenia (all blood cells low) | 163 | 9.2 7.9–10.7ROR 9.4 · χ² 1,175 / p 7e-258 | 9.0 EB05 7.9 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.9 | no trial data cached |
| Hyperbilirubinaemia | 30 | 9.1 6.4–13.0ROR 9.1 · χ² 208 / p 2e-47 | 8.4 EB05 6.0 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
| Blood creatinine increased | 190 | 9.1 7.9–10.5ROR 9.3 · χ² 1,360 / p 5e-298 | 9.0 EB05 7.9 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.1 | no trial data cached |
| Tachypnoea | 39 | 9.0 6.6–12.3ROR 9.1 · χ² 269 / p 9e-61 | 8.4 EB05 6.3 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 | no trial data cached |
| Hypokalaemia (low potassium) | 131 | 8.9 7.5–10.6ROR 9.1 · χ² 914 / p 4e-201 | 8.7 EB05 7.5 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.8 | no trial data cached |
| Ventricular tachycardia | 47 | 8.9 6.7–11.8ROR 8.9 · χ² 320 / p 8e-72 | 8.4 EB05 6.5 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
| Stevens-johnson syndrome (severe blistering skin reaction) | 63 | 8.8 6.9–11.3ROR 8.9 · χ² 430 / p 8e-96 | 8.5 EB05 6.8 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.5 | no trial data cached |
| Haematocrit decreased | 56 | 8.8 6.8–11.4ROR 8.8 · χ² 377 / p 2e-84 | 8.4 EB05 6.6 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious PRR 6.1 | no trial data cached |
| Malnutrition | 31 | 8.7 6.1–12.4ROR 8.8 · χ² 204 / p 1e-46 | 8.0 EB05 5.8 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Aspartate aminotransferase increased | 146 | 8.6 7.3–10.1ROR 8.8 · χ² 973 / p 6e-214 | 8.4 EB05 7.3 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.9 | no trial data cached |
| Pleural effusion | 162 | 8.3 7.1–9.7ROR 8.5 · χ² 1,036 / p 1e-227 | 8.2 EB05 7.2 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Pyrexia (fever) | 552 | 5.0 4.6–5.4ROR 5.3 · χ² 1,780 / p <1e-300 | 5.0 EB05 4.6 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.9 | no trial data cached |
| Pneumonia (lung infection) | 537 | 5.2 4.8–5.6ROR 5.6 · χ² 1,839 / p <1e-300 | 5.2 EB05 4.8 · IC025 +2.2 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 3.5 | no trial data cached |
| Sepsis (blood infection) | 458 | 12.9 11.8–14.1ROR 13.7 · χ² 5,003 / p <1e-300 | 12.8 EB05 11.8 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 8.3 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 363 | 7.5 6.7–8.2ROR 7.8 · χ² 2,032 / p <1e-300 | 7.4 EB05 6.8 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.8 | no trial data cached |
| Diarrhoea (diarrhea) | 354 | 1.7 1.6–1.9ROR 1.8 · χ² 109 / p 9e-26 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.8 | no trial data cached |
| Renal failure (kidney failure) | 333 | 7.8 7.0–8.6ROR 8.1 · χ² 1,971 / p <1e-300 | 7.7 EB05 7.0 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.0 | no trial data cached |
| Dyspnoea (shortness of breath) | 322 | 1.8 1.6–2.0ROR 1.8 · χ² 112 / p 2e-26 | 1.8 EB05 1.6 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.5 | no trial data cached |
| Hypotension (low blood pressure) | 309 | 4.8 4.3–5.4ROR 5.0 · χ² 940 / p 1e-206 | 4.8 EB05 4.4 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.5 | no trial data cached |
| Anaemia (low red blood cells) | 273 | 4.5 4.0–5.0ROR 4.6 · χ² 738 / p 1e-162 | 4.4 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.2 | no trial data cached |
| Rash | 268 | 1.9 1.7–2.2ROR 2.0 · χ² 122 / p 1e-28 | 1.9 EB05 1.7 · IC025 +0.7 | Labeled adverse reaction exact term | serious PRR 2.0 | no trial data cached |
| Febrile neutropenia | 259 | 12.3 10.9–13.8ROR 12.7 · χ² 2,663 / p <1e-300 | 12.2 EB05 11.0 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.9 · 92% clinician | no trial data cached |
| Thrombocytopenia (low platelets) | 257 | 7.2 6.4–8.1ROR 7.5 · χ² 1,372 / p 1e-300 | 7.1 EB05 6.4 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.6 | no trial data cached |
| Respiratory failure | 254 | 10.9 9.7–12.3ROR 11.3 · χ² 2,273 / p <1e-300 | 10.8 EB05 9.7 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.9 | no trial data cached |
| Drug hypersensitivity | 238 | 3.8 3.4–4.3ROR 3.9 · χ² 499 / p 1e-110 | 3.8 EB05 3.4 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.6 | no trial data cached |
| Platelet count decreased | 234 | 6.9 6.1–7.8ROR 7.1 · χ² 1,171 / p 6e-257 | 6.8 EB05 6.1 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.1 · 91% clinician | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Renal tubular necrosis — n=94, PRR 30.1
- Disseminated intravascular coagulation — n=126, PRR 28.1
- Multi-organ failure — n=103, PRR 18.4
- Tubulointerstitial nephritis — n=101, PRR 16.9
- Atelectasis — n=52, PRR 16.8
- Nephropathy toxic — n=53, PRR 14.9
- Leukocytosis — n=80, PRR 13.9
- Septic shock — n=184, PRR 13.3
- Sepsis — n=458, PRR 12.9
- Acute respiratory distress syndrome — n=72, PRR 12.8
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Tazobactam and Piperacillin?
In FDA FAERS, the most frequently co-reported reaction terms for Tazobactam and Piperacillin are pyrexia, pneumonia, sepsis, acute kidney injury, diarrhoea, renal failure. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Tazobactam and Piperacillin have an FDA boxed warning?
No. The FDA label retrieved for Tazobactam and Piperacillin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Tazobactam and Piperacillin causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 8ab9d90d-2f7f-4599-a44f-3d0a8f8ab623, effective 20230315; matched on
openfda.generic_name.exact:"TAZOBACTAM SODIUM AND PIPERACILLIN SODIUM") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 449 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.