Drug · FAERS side-effect profile with label screen
Cefazolin side effects: what 9,070 FDA adverse event reports show
Drug class
Cephalosporin antibacterial
FDA label, Indications wording
Who reports
9,070 reports · 93% serious · 1,031 with death outcome · 49% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Cefazolin for Injection is a cephalosporin antibacterial indicated for: Treatment of the following infections caused by susceptible isolates of the designated microorganisms in adult and pediatric patients 1 month of age and older for whom appropriate .
FDA label, Indications and Usage
What it is
Cefazolin for Injection contains cefazolin sodium, a semi-synthetic cephalosporin. It is the sodium salt of 3-{[(5-methyl-1,3,4-thiadiazol-2-yl)thio]-methyl}-8-oxo-7-[2-(1H-tetrazol-1-yl) acetamido]-5-thia-1-azabicyclo [4.2.0]oct-2-ene-2-carboxylic acid.
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 2Labeled (related wording) 1Likely indication confounding 2Reporting / coding artifact 2Lab value / disease marker 1Not in label — unassessed 32
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.
- 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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 1,033 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 |
|---|---|---|---|---|---|---|
| Lymphoid tissue hypoplasia | 68 | 1,962.9 1,420.3–2,712.9ROR 1,977.7 · χ² 70,610 / p <1e-300 | 812.2 EB05 662.7 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=68 · ♀ 0% (drug 49%) | no trial data cached |
| Thymus hypoplasia | 67 | 1,483.4 1,091.3–2,016.3ROR 1,494.4 · χ² 59,241 / p <1e-300 | 714.4 EB05 582.0 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=67 · ♀ 0% (drug 49%) | no trial data cached |
| Multiple lentigines syndrome | 10 | 814.4 395.7–1,676.2ROR 815.3 · χ² 5,402 / p <1e-300 | 279.6 EB05 162.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Hypoprothrombinaemia | 55 | 514.0 383.9–688.2ROR 517.2 · χ² 22,565 / p <1e-300 | 366.1 EB05 291.9 · IC025 +6.0 3/3 methods agree | Not in label — unassessed | serious n=55 · 100% clinician | no trial data cached |
| Pericarditis fungal | 12 | 506.8 271.2–946.9ROR 507.4 · χ² 4,551 / p <1e-300 | 250.0 EB05 152.4 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Disseminated aspergillosis | 63 | 359.2 275.6–468.1ROR 361.7 · χ² 19,132 / p <1e-300 | 283.7 EB05 229.6 · IC025 +6.1 3/3 methods agree | Not in label — unassessed | serious n=63 · ♀ 0% (drug 49%) | no trial data cached |
| Gastritis fungal | 12 | 300.7 164.8–548.8ROR 301.1 · χ² 2,908 / p <1e-300 | 187.2 EB05 114.1 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Mycobacterial peritonitis | 11 | 298.6 159.3–559.7ROR 299.0 · χ² 2,628 / p <1e-300 | 181.5 EB05 108.2 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Vitamin k deficiency | 34 | 216.0 152.0–306.8ROR 216.8 · χ² 6,451 / p <1e-300 | 177.8 EB05 133.1 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=34 · 100% clinician | no trial data cached |
| Arthrodesis | 70 | 170.9 134.2–217.7ROR 172.2 · χ² 10,843 / p <1e-300 | 152.5 EB05 124.8 · IC025 +5.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=70 · ♀ 100% (drug 49%) | no trial data cached |
| Mycobacterium fortuitum infection | 12 | 160.0 89.2–287.2ROR 160.2 · χ² 1,627 / p <1e-300 | 121.3 EB05 73.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Recurrence of neuromuscular blockade | 11 | 156.8 85.1–288.7ROR 157.0 · χ² 1,451 / p <1e-300 | 117.4 EB05 70.0 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Chorioamnionitis | 11 | 140.1 76.3–257.5ROR 140.3 · χ² 1,304 / p 1e-285 | 107.9 EB05 64.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Vancomycin infusion reaction | 18 | 120.4 75.0–193.3ROR 120.6 · χ² 1,912 / p <1e-300 | 102.3 EB05 68.4 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Incision site infection | 44 | 116.1 85.8–157.1ROR 116.7 · χ² 4,670 / p <1e-300 | 105.6 EB05 81.9 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=44 · ♀ 100% (drug 49%) · 100% clinician | no trial data cached |
| Meningitis fungal | 10 | 103.7 55.0–195.3ROR 103.8 · χ² 877 / p 6e-193 | 83.8 EB05 48.7 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Clostridium test positive | 81 | 89.1 71.5–111.2ROR 89.9 · χ² 6,710 / p <1e-300 | 84.2 EB05 69.9 · IC025 +5.5 3/3 methods agree | Lab value / disease marker | serious n=81 · 100% clinician | no trial data cached |
| Maternal exposure during delivery | 30 | 73.6 51.2–105.9ROR 73.9 · χ² 2,013 / p <1e-300 | 68.4 EB05 50.2 · IC025 +4.4 3/3 methods agree | Reporting / coding artifact | serious n=29 · ♀ 100% (drug 49%) | no trial data cached |
| Kounis syndrome | 67 | 70.6 55.4–90.0ROR 71.1 · χ² 4,393 / p <1e-300 | 67.3 EB05 54.8 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=67 · 100% clinician | no trial data cached |
| Pyroglutamic acidosis | 11 | 68.9 37.8–125.5ROR 69.0 · χ² 650 / p 1e-143 | 60.3 EB05 35.9 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Allergic oedema | 17 | 62.0 38.3–100.4ROR 62.1 · χ² 935 / p 1e-205 | 56.8 EB05 37.5 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| Procedural hypotension | 22 | 60.9 39.9–92.9ROR 61.0 · χ² 1,205 / p 3e-264 | 56.6 EB05 39.4 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=22 · 100% clinician | no trial data cached |
| Foetal exposure during delivery | 16 | 55.3 33.7–90.7ROR 55.4 · χ² 780 / p 5e-172 | 50.9 EB05 33.2 · IC025 +3.5 3/3 methods agree | Reporting / coding artifact | serious n=16 | no trial data cached |
| Tryptase increased | 16 | 53.7 32.7–88.2ROR 53.8 · χ² 758 / p 3e-167 | 49.6 EB05 32.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Urticarial vasculitis | 11 | 50.0 27.5–90.8ROR 50.0 · χ² 470 / p 2e-104 | 45.3 EB05 27.0 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Linear iga disease | 32 | 45.3 31.9–64.2ROR 45.5 · χ² 1,316 / p 2e-288 | 43.4 EB05 32.2 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=32 · ♀ 77% (drug 49%) · 100% clinician | no trial data cached |
| Hyperthermia malignant | 27 | 43.0 29.4–62.9ROR 43.2 · χ² 1,047 / p 5e-230 | 41.1 EB05 29.7 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=27 · ♀ 22% (drug 49%) · 100% clinician | no trial data cached |
| Delivery | 11 | 39.0 21.5–70.8ROR 39.1 · χ² 364 / p 2e-81 | 36.2 EB05 21.5 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious n=11 | no trial data cached |
| Cataract subcapsular | 10 | 38.6 20.7–72.1ROR 38.6 · χ² 324 / p 1e-72 | 35.6 EB05 20.6 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Dysbiosis | 13 | 38.1 22.0–65.9ROR 38.2 · χ² 426 / p 5e-95 | 35.7 EB05 22.2 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Acute generalised exanthematous pustulosis | 125 | 38.0 31.8–45.2ROR 38.5 · χ² 4,389 / p <1e-300 | 37.2 EB05 32.0 · IC025 +4.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 23.0 · 98% clinician | no trial data cached |
| Scedosporium infection | 11 | 37.3 20.5–67.6ROR 37.3 · χ² 347 / p 9e-78 | 34.7 EB05 20.6 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Toxic shock syndrome | 10 | 37.1 19.9–69.2ROR 37.1 · χ² 311 / p 7e-70 | 34.3 EB05 19.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Red man syndrome | 14 | 36.9 21.8–62.5ROR 36.9 · χ² 446 / p 3e-99 | 34.7 EB05 22.0 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Cytomegalovirus viraemia | 68 | 36.5 28.7–46.3ROR 36.7 · χ² 2,275 / p <1e-300 | 35.6 EB05 29.0 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=68 · ♀ 0% (drug 49%) | no trial data cached |
| Episcleritis | 10 | 34.1 18.3–63.6ROR 34.1 · χ² 285 / p 4e-64 | 31.7 EB05 18.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Delayed graft function | 10 | 33.1 17.8–61.9ROR 33.2 · χ² 276 / p 2e-62 | 30.9 EB05 17.8 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Shoulder arthroplasty | 37 | 32.7 23.6–45.2ROR 32.8 · χ² 1,089 / p 3e-239 | 31.8 EB05 24.1 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=37 · ♀ 100% (drug 49%) | no trial data cached |
| Clostridium difficile colitis | 147 | 32.4 27.6–38.1ROR 33.0 · χ² 4,388 / p <1e-300 | 31.9 EB05 27.8 · IC025 +4.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 20.3 · ♀ 28% (drug 49%) | no trial data cached |
| Amniotic cavity infection | 10 | 32.4 17.4–60.5ROR 32.5 · χ² 270 / p 5e-61 | 30.3 EB05 17.5 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=10 | 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 |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 612 | 1.1 1.0–1.2ROR 1.1 · χ² 3 / p 0.035 | 1.1 EB05 1.0 · IC025 -0.0 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.8 · 90% clinician | no trial data cached |
| Hypotension (low blood pressure) | 559 | 6.5 6.0–7.0ROR 6.8 · χ² 2,596 / p <1e-300 | 6.4 EB05 6.0 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 93% clinician | no trial data cached |
| Anaphylactic reaction (severe allergic reaction) | 488 | 20.7 19.0–22.6ROR 21.8 · χ² 9,079 / p <1e-300 | 20.5 EB05 19.0 · IC025 +4.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 12.8 · 93% clinician | no trial data cached |
| Rash | 471 | 2.5 2.3–2.7ROR 2.6 · χ² 436 / p 4e-97 | 2.5 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.2 | no trial data cached |
| Renal failure (kidney failure) | 436 | 7.6 6.9–8.3ROR 7.9 · χ² 2,481 / p <1e-300 | 7.5 EB05 6.9 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.7 | no trial data cached |
| Pain | 386 | 1.5 1.3–1.6ROR 1.5 · χ² 55 / p 5e-14 | 1.5 EB05 1.3 · IC025 +0.4 | Not in label — unassessed | serious PRR 1.4 | no trial data cached |
| Pyrexia (fever) | 381 | 2.5 2.3–2.8ROR 2.6 · χ² 362 / p 6e-81 | 2.5 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 1.9 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 377 | 5.7 5.2–6.3ROR 5.9 · χ² 1,476 / p <1e-300 | 5.7 EB05 5.2 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.5 | no trial data cached |
| Anaphylactic shock | 341 | 31.2 28.1–34.6ROR 32.3 · χ² 9,805 / p <1e-300 | 30.7 EB05 28.1 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 19.1 · 94% clinician | no trial data cached |
| Off label use (used outside approved label) | 333 | 0.9 0.8–1.0ROR 0.9 · χ² 5 / p 0.014 | 0.9 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 0.9 | no trial data cached |
| Drug hypersensitivity | 307 | 3.7 3.3–4.1ROR 3.8 · χ² 595 / p 1e-131 | 3.6 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.2 · ♀ 71% (drug 49%) | no trial data cached |
| Anxiety | 296 | 2.4 2.1–2.7ROR 2.4 · χ² 243 / p 3e-55 | 2.4 EB05 2.2 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Nausea | 293 | 0.9 0.8–1.0ROR 0.9 · χ² 7 / p 0.004 | 0.9 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 1.0 | no trial data cached |
| Urticaria (hives) | 274 | 3.8 3.4–4.3ROR 3.9 · χ² 569 / p 5e-126 | 3.8 EB05 3.4 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | no trial data cached |
| Dyspnoea (shortness of breath) | 268 | 1.1 1.0–1.2ROR 1.1 · χ² 2 / p 0.069 | 1.1 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 0.9 | 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.
- Lymphoid tissue hypoplasia — n=68, PRR 1,962.9
- Thymus hypoplasia — n=67, PRR 1,483.4
- Hypoprothrombinaemia — n=55, PRR 514.0
- Disseminated aspergillosis — n=63, PRR 359.2
- Vitamin k deficiency — n=34, PRR 216.0
- Incision site infection — n=44, PRR 116.1
- Kounis syndrome — n=67, PRR 70.6
- Procedural hypotension — n=22, PRR 60.9
- Linear iga disease — n=32, PRR 45.3
- Hyperthermia malignant — n=27, PRR 43.0
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 Cefazolin?
In FDA FAERS, the most frequently co-reported reaction terms for Cefazolin are hypotension, anaphylactic reaction, rash, renal failure, pain, pyrexia. 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 Cefazolin have an FDA boxed warning?
No. The FDA label retrieved for Cefazolin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Cefazolin 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 1367568c-7d27-479f-a4c5-58e99942f686, effective 20251101; matched on
openfda.generic_name.exact:"CEFAZOLIN") - 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, 1,073 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.