Piperacillin and Tazobactam side effects: what 19,504 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Piperacillin Sodium And Tazobactam Sodium (Piperacillin And Tazobactam)
Who reports
19,504 reports · 95% serious · 4,339 with death outcome · 42% female
Used for
Piperacillin and tazobactam for injection is a combination of piperacillin, a penicillin-class antibacterial and tazobactam, a beta-lactamase inhibitor, indicated for treatment of: Intra-abdominal infections in adult and pediatric patients 2 months of .
What it is
Piperacillin and Tazobactam for 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.
Boxed warning
PHARMACY BULK PACKAGE – NOT FOR DIRECT INFUSION PHARMACY BULK PACKAGE – NOT FOR DIRECT INFUSION
Causality screen of the 40 strongest signals
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. 1,116 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Antibiotic level above therapeutic | 32 | 93.4 65.1–134.1ROR 93.6 · χ² 2,605 / p <1e-300 | 81.9 EB05 60.7 · IC025 +4.6 3/3 methods agree | Lab value / disease marker | serious n=31 | not reported in cached trials |
| Geotrichum infection | 16 | 87.4 52.5–145.5ROR 87.5 · χ² 1,184 / p 9e-260 | 74.0 EB05 48.3 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Trichosporon infection | 28 | 81.8 55.7–120.1ROR 81.9 · χ² 1,999 / p <1e-300 | 72.4 EB05 52.5 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Spinal muscular atrophy | 17 | 72.4 44.3–118.3ROR 72.4 · χ² 1,054 / p 2e-231 | 63.2 EB05 41.8 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Pyroglutamic acidosis | 22 | 66.1 43.0–101.6ROR 66.1 · χ² 1,266 / p 1e-277 | 59.2 EB05 41.2 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=22 · 100% clinician | not reported in cached trials |
| Acid base balance abnormal | 13 | 65.3 37.3–114.3ROR 65.3 · χ² 716 / p 5e-158 | 56.7 EB05 35.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=13 | not reported in cached trials |
| Choroiditis | 20 | 60.4 38.5–94.8ROR 60.5 · χ² 1,050 / p 1e-230 | 54.4 EB05 37.2 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=20 · 90% clinician | not reported in cached trials |
| Scrotal abscess | 19 | 56.9 35.9–90.2ROR 56.9 · χ² 938 / p 3e-206 | 51.4 EB05 34.8 · IC025 +3.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=19 | not reported in cached trials |
| Linear iga disease | 82 | 55.7 44.6–69.5ROR 55.9 · χ² 4,132 / p <1e-300 | 52.3 EB05 43.5 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=82 · 100% clinician | not reported in cached trials |
| Genital abscess | 19 | 52.7 33.3–83.6ROR 52.8 · χ² 870 / p 2e-191 | 48.0 EB05 32.5 · IC025 +3.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=19 | not reported in cached trials |
| Clostridium test positive | 99 | 51.1 41.8–62.5ROR 51.3 · χ² 4,591 / p <1e-300 | 48.4 EB05 40.9 · IC025 +5.0 3/3 methods agree | Lab value / disease marker | serious n=98 · 94% clinician | not reported in cached trials |
| Antimicrobial susceptibility test resistant | 14 | 50.5 29.5–86.3ROR 50.5 · χ² 602 / p 4e-133 | 45.5 EB05 28.8 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious n=14 | not reported in cached trials |
| Pneumococcal sepsis | 24 | 41.1 27.3–61.8ROR 41.1 · χ² 866 / p 1e-190 | 38.5 EB05 27.2 · IC025 +3.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=24 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Disseminated mucormycosis | 14 | 40.2 23.6–68.6ROR 40.2 · χ² 479 / p 2e-106 | 37.0 EB05 23.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=14 | not reported in cached trials |
| Symmetrical drug-related intertriginous and flexural exanthema | 28 | 39.3 27.0–57.3ROR 39.4 · χ² 971 / p 1e-213 | 37.1 EB05 26.9 · IC025 +3.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=27 · ♀ 62% (drug 42%) · 100% clinician | not reported in cached trials |
| Necrosis ischaemic | 16 | 38.5 23.4–63.3ROR 38.5 · χ² 528 / p 4e-117 | 35.7 EB05 23.3 · IC025 +3.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=16 | not reported in cached trials |
| Systemic candida | 85 | 38.3 30.9–47.6ROR 38.5 · χ² 2,946 / p <1e-300 | 36.7 EB05 30.6 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=85 · 96% clinician | not reported in cached trials |
| Nephritis interstitial | 44 | 38.2 28.3–51.5ROR 38.2 · χ² 1,501 / p <1e-300 | 36.3 EB05 28.2 · IC025 +4.2 3/3 methods agree | Labeled (related wording) related wording | serious n=32 · 100% clinician | not reported in cached trials |
| Respiratory tract infection bacterial | 17 | 37.8 23.3–61.3ROR 37.8 · χ² 553 / p 2e-122 | 35.2 EB05 23.3 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=17 | not reported in cached trials |
| Pneumatosis | 15 | 37.5 22.4–62.7ROR 37.5 · χ² 480 / p 1e-106 | 34.8 EB05 22.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Perineal abscess | 15 | 37.2 22.3–62.3ROR 37.3 · χ² 477 / p 6e-106 | 34.6 EB05 22.2 · IC025 +3.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=15 | not reported in cached trials |
| Lower respiratory tract infection bacterial | 16 | 34.5 21.0–56.7ROR 34.5 · χ² 472 / p 7e-105 | 32.3 EB05 21.0 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious n=16 | not reported in cached trials |
| Fungaemia | 48 | 34.0 25.5–45.3ROR 34.1 · χ² 1,458 / p <1e-300 | 32.6 EB05 25.6 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=48 · 100% clinician | not reported in cached trials |
| Respiratory tract infection fungal | 16 | 33.4 20.3–54.9ROR 33.4 · χ² 456 / p 1e-101 | 31.3 EB05 20.4 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious n=16 | not reported in cached trials |
| Acinetobacter infection | 32 | 32.7 23.0–46.5ROR 32.8 · χ² 924 / p 3e-203 | 31.2 EB05 23.2 · IC025 +3.8 3/3 methods agree | Likely indication confounding term in indications | serious n=31 · 100% clinician | not reported in cached trials |
| Enterococcus test positive | 19 | 32.2 20.4–50.9ROR 32.3 · χ² 528 / p 4e-117 | 30.4 EB05 20.6 · IC025 +3.4 3/3 methods agree | Lab value / disease marker | serious n=19 | not reported in cached trials |
| Pseudomembranous colitis | 63 | 31.0 24.2–39.8ROR 31.1 · χ² 1,750 / p <1e-300 | 29.9 EB05 24.2 · IC025 +4.2 3/3 methods agree | Labeled adverse reaction exact term | serious n=63 · 92% clinician | NCT00402727: 1/426 (0.2%) on Piperacillin and Tazobactam (serious AE) |
| Eosinophilic pneumonia acute | 24 | 30.8 20.5–46.1ROR 30.8 · χ² 643 / p 4e-142 | 29.3 EB05 20.7 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious n=24 · 100% clinician | not reported in cached trials |
| Pseudomonal bacteraemia | 23 | 30.3 20.0–45.8ROR 30.3 · χ² 605 / p 7e-134 | 28.8 EB05 20.2 · IC025 +3.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=23 | not reported in cached trials |
| Candida sepsis | 24 | 29.4 19.6–44.2ROR 29.5 · χ² 614 / p 7e-136 | 28.1 EB05 19.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=24 · 100% clinician | not reported in cached trials |
| Jarisch-herxheimer reaction | 19 | 29.4 18.6–46.3ROR 29.4 · χ² 479 / p 2e-106 | 27.9 EB05 18.8 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Pneumonia necrotising | 17 | 29.2 18.0–47.3ROR 29.2 · χ² 424 / p 2e-94 | 27.7 EB05 18.3 · IC025 +3.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=17 | not reported in cached trials |
| Abdominal compartment syndrome | 16 | 28.3 17.2–46.5ROR 28.3 · χ² 384 / p 7e-86 | 26.8 EB05 17.5 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Anaemia haemolytic autoimmune | 21 | 27.5 17.9–42.5ROR 27.6 · χ² 498 / p 1e-110 | 26.3 EB05 18.1 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=21 · 100% clinician | not reported in cached trials |
| Renal tubular necrosis | 243 | 27.2 24.0–30.9ROR 27.6 · χ² 5,961 / p <1e-300 | 26.5 EB05 23.8 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious PRR 16.2 · 96% clinician | not reported in cached trials |
| Delayed graft function | 17 | 26.5 16.4–42.8ROR 26.5 · χ² 382 / p 2e-85 | 25.2 EB05 16.6 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=17 | not reported in cached trials |
| Fusarium infection | 16 | 25.7 15.7–42.2ROR 25.8 · χ² 348 / p 7e-78 | 24.5 EB05 15.9 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Tracheobronchitis | 18 | 25.6 16.0–40.9ROR 25.6 · χ² 392 / p 2e-87 | 24.4 EB05 16.3 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Serratia infection | 17 | 25.2 15.6–40.8ROR 25.3 · χ² 363 / p 3e-81 | 24.1 EB05 15.8 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Red man syndrome | 20 | 24.6 15.8–38.4ROR 24.7 · χ² 421 / p 9e-94 | 23.6 EB05 16.1 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Piperacillin and Tazobactam as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (1 of 40 signal terms matched).
- NCT03269994 — Does Cefoxitin or Piperacillin-Tazobactam Prevent Postoperative Surgical Site Infections After Pancreatoduoden (N=967, PHASE3; 1 AE terms posted; arms: Cefoxitin; Piperacillin-tazobactam)
- NCT00402727 — Comparison of Sequential IV/PO Moxifloxacin With IV Piperacillin/Tazobactam Followed by PO Amoxicillin/Clavula (N=813, PHASE3; 41 AE terms posted; arms: Moxifloxacin; PIP/TAZ-AMC)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
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 |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 1,665 | 1.4 1.3–1.4ROR 1.4 · χ² 169 / p 7e-39 | 1.4 EB05 1.3 · IC025 +0.4 | Reporting / coding artifact | serious PRR 2.3 · 93% clinician | not reported in cached trials |
| Pyrexia (fever) | 1,458 | 4.5 4.3–4.8ROR 4.8 · χ² 4,075 / p <1e-300 | 4.5 EB05 4.3 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.4 | NCT00402727: 7/426 (1.6%) on Piperacillin and Tazobactam |
| Acute kidney injury (sudden kidney damage) | 1,334 | 9.5 9.0–10.0ROR 10.1 · χ² 10,110 / p <1e-300 | 9.4 EB05 9.0 · IC025 +3.1 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 5.7 · 93% clinician | not reported in cached trials |
| Off label use (used outside approved label) | 1,204 | 1.5 1.4–1.6ROR 1.5 · χ² 203 / p 2e-46 | 1.5 EB05 1.4 · IC025 +0.5 | Reporting / coding artifact | serious PRR 1.6 · 91% clinician | not reported in cached trials |
| Pneumonia (lung infection) | 997 | 3.3 3.1–3.5ROR 3.4 · χ² 1,637 / p <1e-300 | 3.3 EB05 3.1 · IC025 +1.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 2.1 | NCT00402727: 1/377 (0.3%) on Piperacillin and Tazobactam (serious AE) |
| Sepsis (blood infection) | 884 | 8.6 8.0–9.2ROR 8.9 · χ² 5,894 / p <1e-300 | 8.5 EB05 8.0 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | NCT00402727: 1/426 (0.2%) on Piperacillin and Tazobactam (serious AE) |
| Diarrhoea (diarrhea) | 809 | 1.4 1.3–1.4ROR 1.4 · χ² 76 / p 1e-18 | 1.4 EB05 1.3 · IC025 +0.3 | Labeled — boxed warning exact term | serious PRR 1.4 | NCT00402727: 10/426 (2.3%) on Piperacillin and Tazobactam |
| Thrombocytopenia (low platelets) | 745 | 7.2 6.7–7.8ROR 7.5 · χ² 3,984 / p <1e-300 | 7.2 EB05 6.7 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.4 · 93% clinician | not reported in cached trials |
| Dyspnoea (shortness of breath) | 733 | 1.4 1.3–1.5ROR 1.4 · χ² 83 / p 3e-20 | 1.4 EB05 1.3 · IC025 +0.4 | Not in label — unassessed | serious PRR 1.1 | not reported in cached trials |
| Hypotension (low blood pressure) | 726 | 3.9 3.6–4.2ROR 4.0 · χ² 1,577 / p <1e-300 | 3.9 EB05 3.7 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.7 | not reported in cached trials |
| Rash | 655 | 1.6 1.5–1.8ROR 1.6 · χ² 160 / p 6e-37 | 1.6 EB05 1.5 · IC025 +0.6 | Labeled — boxed warning exact term | serious PRR 1.9 | not reported in cached trials |
| Septic shock | 620 | 15.6 14.5–16.9ROR 16.1 · χ² 8,373 / p <1e-300 | 15.4 EB05 14.4 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 9.3 · 92% clinician | not reported in cached trials |
| Respiratory failure | 612 | 9.1 8.4–9.8ROR 9.3 · χ² 4,373 / p <1e-300 | 9.0 EB05 8.4 · IC025 +3.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.5 | not reported in cached trials |
| Febrile neutropenia | 603 | 9.9 9.1–10.7ROR 10.2 · χ² 4,769 / p <1e-300 | 9.8 EB05 9.1 · IC025 +3.1 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 6.0 · 94% clinician | not reported in cached trials |
| Condition aggravated | 585 | 2.1 1.9–2.3ROR 2.1 · χ² 333 / p 9e-75 | 2.1 EB05 1.9 · IC025 +0.9 | Reporting / coding artifact | serious PRR 1.9 · 92% clinician | not reported in cached trials |
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.
- Trichosporon infection — n=28, PRR 81.8
- Pyroglutamic acidosis — n=22, PRR 66.1
- Choroiditis — n=20, PRR 60.4
- Linear iga disease — n=82, PRR 55.7
- Systemic candida — n=85, PRR 38.3
- Fungaemia — n=48, PRR 34.0
- Candida sepsis — n=24, PRR 29.4
- Anaemia haemolytic autoimmune — n=21, PRR 27.5
- Renal tubular necrosis — n=243, PRR 27.2
- Red man syndrome — n=20, PRR 24.6
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 Piperacillin and Tazobactam?
In FDA FAERS, the most frequently co-reported reaction terms for Piperacillin and Tazobactam are pyrexia, acute kidney injury, pneumonia, sepsis, diarrhoea, thrombocytopenia. 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 Piperacillin and Tazobactam have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: PHARMACY BULK PACKAGE – NOT FOR DIRECT INFUSION PHARMACY BULK PACKAGE – NOT FOR DIRECT INFUSION
Do FAERS signals prove that Piperacillin and Tazobactam 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 68d5384d-1691-4afc-8a1a-488f8e2ef2c5, effective 20250226; matched on
openfda.generic_name.exact:"PIPERACILLIN SODIUM AND TAZOBACTAM 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, 1,156 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 - ClinicalTrials.gov API v2 (query
PIPERACILLIN, results-bearing studies sorted by enrollment)
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.