Piperacillin and Tazobactam side effects: what 26,370 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Piperacillin Sodium,Tazobactam Sodium (Piperacillin And Tazobactam)
Who reports
26,370 reports · 98% serious · 5,395 with death outcome · 42% female
Used for
Piperacillin and tazobactam for injection, for intravenous use 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 pedia.
What it is
Piperacillin and Tazobactam for Injection, USP 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
None in the current label
Causality screen of the 40 strongest signals
What the badges mean
- 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.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- 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, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,078 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 |
|---|---|---|---|---|---|---|
| New onset refractory status epilepticus | 27 | 271.3 175.2–420.1ROR 271.5 · calibrated p 2e-10 ✓ | 176.7 EB05 127.6 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=27 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Protothecosis | 21 | 228.6 140.6–371.6ROR 228.8 · calibrated p 1e-9 ✓ | 152.8 EB05 105.5 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=21 · ♀ 100% (drug 42%) · 100% clinician | not reported in cached trials |
| Retinitis viral | 20 | 159.9 98.9–258.7ROR 160.1 · calibrated p 2e-8 ✓ | 118.3 EB05 80.8 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=20 · ♀ 100% (drug 42%) | not reported in cached trials |
| Choroiditis | 55 | 136.4 102.5–181.6ROR 136.7 · calibrated p 2e-8 ✓ | 111.9 EB05 89.2 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious n=55 · ♀ 0% (drug 42%) | not reported in cached trials |
| Intra-abdominal pressure increased | 20 | 116.1 72.6–185.7ROR 116.2 · calibrated p 2e-7 ✓ | 92.5 EB05 63.3 · IC025 +4.1 3/3 methods agree | Lab value / disease marker | serious n=20 · ♀ 100% (drug 42%) | not reported in cached trials |
| Trichosporon infection | 50 | 114.9 85.4–154.6ROR 115.1 · calibrated p 7e-8 ✓ | 96.7 EB05 76.2 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=50 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Geotrichum infection | 26 | 110.7 73.5–166.9ROR 110.8 · calibrated p 2e-7 ✓ | 90.9 EB05 65.2 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=26 · 100% clinician | not reported in cached trials |
| Delusion of grandeur | 50 | 100.0 74.5–134.1ROR 100.1 · calibrated p 2e-7 ✓ | 85.9 EB05 67.7 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=50 · ♀ 0% (drug 42%) | not reported in cached trials |
| Aeromonas infection | 17 | 85.4 51.8–140.9ROR 85.5 · calibrated p 2e-6 ✓ | 71.2 EB05 47.1 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Clostridium test positive | 195 | 78.0 67.4–90.4ROR 78.6 · calibrated p 7e-7 ✓ | 70.6 EB05 62.7 · IC025 +5.7 3/3 methods agree | Lab value / disease marker | serious n=195 · 97% clinician | not reported in cached trials |
| Spinal muscular atrophy | 24 | 77.7 51.1–118.2ROR 77.8 · calibrated p 2e-6 ✓ | 67.2 EB05 47.5 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=24 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Pyroglutamic acidosis | 33 | 75.6 52.9–108.1ROR 75.7 · calibrated p 2e-6 ✓ | 66.5 EB05 49.6 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=33 · 100% clinician | not reported in cached trials |
| Alveolar lung disease | 16 | 72.5 43.4–120.9ROR 72.5 · calibrated p 5e-6 ✓ | 61.8 EB05 40.3 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Rhinocerebral mucormycosis | 28 | 70.8 48.1–104.2ROR 70.9 · calibrated p 3e-6 ✓ | 62.4 EB05 45.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=28 · 100% clinician | not reported in cached trials |
| Linear iga disease | 132 | 68.5 57.3–81.8ROR 68.8 · calibrated p 2e-6 ✓ | 62.5 EB05 54.0 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious n=132 · 100% clinician | not reported in cached trials |
| Anal inflammation | 47 | 63.5 47.2–85.5ROR 63.6 · calibrated p 5e-6 ✓ | 57.5 EB05 45.0 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=47 · ♀ 0% (drug 42%) · 98% clinician | not reported in cached trials |
| Respiratory tract infection bacterial | 37 | 63.4 45.4–88.7ROR 63.5 · calibrated p 5e-6 ✓ | 57.1 EB05 43.3 · IC025 +4.5 3/3 methods agree | Labeled (related wording) related wording | serious n=37 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Trichoglossia | 29 | 60.4 41.4–88.2ROR 60.5 · calibrated p 8e-6 ✓ | 54.3 EB05 39.6 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 0% (drug 42%) | not reported in cached trials |
| Congenital aplasia | 20 | 58.9 37.4–92.8ROR 59.0 · calibrated p 1e-5 ✓ | 52.3 EB05 35.7 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=20 · 100% clinician | not reported in cached trials |
| Acid base balance abnormal | 15 | 56.2 33.3–95.0ROR 56.3 · calibrated p 2e-5 ✓ | 49.5 EB05 31.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Intensive care unit acquired weakness | 25 | 55.7 37.1–83.5ROR 55.7 · calibrated p 1e-5 ✓ | 50.2 EB05 35.7 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=24 | not reported in cached trials |
| Disseminated mucormycosis | 25 | 54.7 36.5–82.1ROR 54.8 · calibrated p 2e-5 ✓ | 49.4 EB05 35.2 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=25 · 100% clinician | not reported in cached trials |
| Symmetrical drug-related intertriginous and flexural exanthema | 50 | 53.5 40.2–71.2ROR 53.6 · calibrated p 1e-5 ✓ | 49.2 EB05 38.8 · IC025 +4.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=47 · 100% clinician | not reported in cached trials |
| Antibiotic level above therapeutic | 25 | 53.0 35.3–79.4ROR 53.0 · calibrated p 2e-5 ✓ | 48.0 EB05 34.2 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious n=25 · 96% clinician | not reported in cached trials |
| Dysbiosis | 50 | 52.9 39.7–70.4ROR 53.0 · calibrated p 1e-5 ✓ | 48.7 EB05 38.4 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=50 · ♀ 69% (drug 42%) | not reported in cached trials |
| Pulmonary mucormycosis | 32 | 52.6 36.8–75.2ROR 52.6 · calibrated p 2e-5 ✓ | 48.0 EB05 35.6 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=32 · 94% clinician | not reported in cached trials |
| Cholangitis infective | 15 | 48.2 28.6–81.1ROR 48.2 · calibrated p 5e-5 ✓ | 43.1 EB05 27.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Stoma closure | 17 | 47.4 29.1–77.3ROR 47.4 · calibrated p 5e-5 ✓ | 42.8 EB05 28.3 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Necrosis ischaemic | 26 | 47.3 31.8–70.2ROR 47.3 · calibrated p 4e-5 ✓ | 43.3 EB05 31.1 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=26 · ♀ 100% (drug 42%) | not reported in cached trials |
| Systemic candida | 135 | 46.0 38.7–54.7ROR 46.2 · calibrated p 2e-5 ✓ | 43.2 EB05 37.5 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=135 · 95% clinician | not reported in cached trials |
| Pneumatosis | 23 | 43.3 28.5–65.9ROR 43.4 · calibrated p 7e-5 ✓ | 39.9 EB05 28.0 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=23 | not reported in cached trials |
| Antimicrobial susceptibility test resistant | 16 | 42.9 26.0–71.0ROR 43.0 · calibrated p 9e-5 ✓ | 39.0 EB05 25.5 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=16 | not reported in cached trials |
| Sars-cov-2 test negative | 35 | 42.9 30.5–60.2ROR 42.9 · calibrated p 6e-5 ✓ | 39.9 EB05 30.0 · IC025 +4.1 3/3 methods agree | Reporting / coding artifact | serious n=35 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Pseudomonal bacteraemia | 40 | 39.8 29.0–54.6ROR 39.8 · calibrated p 8e-5 ✓ | 37.3 EB05 28.6 · IC025 +4.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=40 · 90% clinician | not reported in cached trials |
| Congestive hepatopathy | 21 | 39.4 25.4–61.0ROR 39.4 · calibrated p 1e-4 ✓ | 36.4 EB05 25.1 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=21 | not reported in cached trials |
| Endometrial disorder | 19 | 39.1 24.7–61.9ROR 39.1 · calibrated p 1e-4 ✓ | 36.0 EB05 24.4 · IC025 +3.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=19 | not reported in cached trials |
| Pneumococcal sepsis | 30 | 38.4 26.6–55.3ROR 38.4 · calibrated p 1e-4 ✓ | 35.9 EB05 26.3 · IC025 +3.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=30 · ♀ 0% (drug 42%) · 100% clinician | not reported in cached trials |
| Fungaemia | 71 | 37.8 29.8–47.9ROR 37.9 · calibrated p 9e-5 ✓ | 35.8 EB05 29.3 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=71 · 100% clinician | not reported in cached trials |
| Sjs-ten overlap | 29 | 37.2 25.6–54.0ROR 37.2 · calibrated p 1e-4 ✓ | 34.8 EB05 25.4 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=29 · 100% clinician | not reported in cached trials |
| Enterococcus test positive | 29 | 37.0 25.5–53.6ROR 37.0 · calibrated p 1e-4 ✓ | 34.6 EB05 25.3 · IC025 +3.9 3/3 methods agree | Lab value / disease marker | serious n=29 · ♀ 64% (drug 42%) | 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 (0 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) | 2,925 | 1.8 1.7–1.8ROR 1.9 · calibrated p 0.867 | 1.8 EB05 1.7 · IC025 +0.8 | Reporting / coding artifact | serious PRR 2.9 · 95% clinician | not reported in cached trials |
| Off label use (used outside approved label) | 2,607 | 2.4 2.3–2.5ROR 2.5 · calibrated p 0.794 | 2.4 EB05 2.3 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 2.5 · 95% clinician | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 2,014 | 10.6 10.2–11.1ROR 11.4 · calibrated p 0.020 ✓ | 10.5 EB05 10.1 · IC025 +3.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.2 · 97% clinician | not reported in cached trials |
| Pyrexia (fever) | 1,723 | 4.0 3.8–4.2ROR 4.2 · calibrated p 0.346 | 4.0 EB05 3.8 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.9 · 93% clinician | NCT00402727: 7/426 (1.6%) on Piperacillin and Tazobactam |
| Condition aggravated | 1,088 | 2.9 2.7–3.0ROR 3.0 · calibrated p 0.642 | 2.9 EB05 2.7 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious PRR 2.6 · 95% clinician | not reported in cached trials |
| Diarrhoea (diarrhea) | 1,076 | 1.3 1.3–1.4ROR 1.3 · calibrated p 0.538 | 1.3 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.4 · 93% clinician | NCT00402727: 10/426 (2.3%) on Piperacillin and Tazobactam |
| Thrombocytopenia (low platelets) | 1,019 | 7.3 6.9–7.8ROR 7.6 · calibrated p 0.079 | 7.2 EB05 6.9 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.4 · 96% clinician | not reported in cached trials |
| Pneumonia (lung infection) | 977 | 2.4 2.3–2.6ROR 2.5 · calibrated p 0.830 | 2.4 EB05 2.3 · IC025 +1.2 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 1.5 · 94% clinician | NCT00402727: 1/377 (0.3%) on Piperacillin and Tazobactam (serious AE) |
| Neutropenia (low neutrophils (infection-fighting cells)) | 945 | 5.6 5.2–5.9ROR 5.7 · calibrated p 0.168 | 5.5 EB05 5.2 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 · 94% clinician | not reported in cached trials |
| Drug reaction with eosinophilia and systemic symptoms | 916 | 29.5 27.7–31.5ROR 30.6 · calibrated p 2e-4 ✓ | 28.5 EB05 27.0 · IC025 +4.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 16.8 · 98% clinician | not reported in cached trials |
| Febrile neutropenia | 875 | 10.6 10.0–11.4ROR 11.0 · calibrated p 0.023 ✓ | 10.5 EB05 9.9 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.2 · 96% clinician | not reported in cached trials |
| Rash | 832 | 1.5 1.4–1.6ROR 1.5 · calibrated p 0.671 | 1.5 EB05 1.4 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 1.9 · 92% clinician | not reported in cached trials |
| Dyspnoea (shortness of breath) | 785 | 1.1 1.0–1.2ROR 1.1 · calibrated p 0.378 | 1.1 EB05 1.0 · IC025 +0.0 | Not in label — unassessed | serious PRR 0.9 · 90% clinician | not reported in cached trials |
| Drug interaction | 780 | 3.9 3.7–4.2ROR 4.0 · calibrated p 0.376 | 3.9 EB05 3.7 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 2.6 · 96% clinician | not reported in cached trials |
| Sepsis (blood infection) | 778 | 5.6 5.2–6.0ROR 5.7 · calibrated p 0.170 | 5.5 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.3 · 93% clinician | NCT00402727: 1/426 (0.2%) on Piperacillin and Tazobactam (serious AE) |
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.
- New onset refractory status epilepticus — n=27, PRR 271.3
- Protothecosis — n=21, PRR 228.6
- Retinitis viral — n=20, PRR 159.9
- Choroiditis — n=55, PRR 136.4
- Trichosporon infection — n=50, PRR 114.9
- Geotrichum infection — n=26, PRR 110.7
- Delusion of grandeur — n=50, PRR 100.0
- Spinal muscular atrophy — n=24, PRR 77.7
- Pyroglutamic acidosis — n=33, PRR 75.6
- Rhinocerebral mucormycosis — n=28, PRR 70.8
✓ A hand-written Bradford Hill causality assessment exists for this drug: Methotrexate Sodium ↔ Rheumatoid Arthritis.
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 acute kidney injury, pyrexia, diarrhoea, thrombocytopenia, pneumonia, neutropenia. 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?
No. The FDA label retrieved for Piperacillin and Tazobactam has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
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 2cd82553-79dc-45f0-9755-2c08df524ed5, effective 20251031; matched on
openfda.generic_name.exact:"PIPERACILLIN SODIUM,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, 1,118 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 2026-10-14. 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.