Cefoxitin side effects: what 1,173 FDA adverse event reports show

Cefoxitin · 39 reaction terms · 699 drug–reaction co-reports · data 2026-09-14

Drug class

Not stated in label

Who reports

1,173 reports · 88% serious · 105 with death outcome · 56% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Treatment Cefoxitin for Injection, USP is indicated for the treatment of serious infections caused by susceptible strains of the designated microorganisms in the diseases listed below. (1) Lower respiratory tract infections , including pneumonia and lu.

FDA label, Indications and Usage

What it is

DESCRIPTION Cefoxitin for Injection, USP contains cefoxitin sodium a semi-synthetic, broad-spectrum cephalosporin antibiotic for parenteral administration. It is derived from cephalosporin C, which is produced by Cephalosporium Acremonium .

FDA label, Description section

Boxed warning

PHARMACY BULK PACKAGE – NOT FOR DIRECT INFUSION

FDA 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 26 strongest signals

Labeled — boxed warning 3Labeled (related wording) 1Reporting / coding artifact 3Not in label — unassessed 19

What the badges mean

Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
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.
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. 13 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Drug resistance	83	57.9 47.0–71.3ROR 62.2 · χ² 4,575 / p <1e-300	57.0 EB05 47.4 · IC025 +5.1 3/3 methods agree	Reporting / coding artifact	serious PRR 27.5 · 98% clinician	no trial data cached
Drug reaction with eosinophilia and systemic symptoms	74	51.9 41.6–64.7ROR 55.3 · χ² 3,635 / p <1e-300	51.1 EB05 42.0 · IC025 +4.9 3/3 methods agree	Not in label — unassessed	serious PRR 33.8 · 96% clinician	no trial data cached
Rash maculo-papular	36	29.1 21.1–40.1ROR 30.0 · χ² 947 / p 3e-208	28.6 EB05 21.6 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious PRR 19.8 · 100% clinician	no trial data cached
Eosinophilia	21	21.5 14.1–32.8ROR 21.9 · χ² 390 / p 4e-87	21.1 EB05 14.4 · IC025 +3.1 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 10.5 · ♀ 30% (drug 56%) · 100% clinician	no trial data cached
Nephropathy toxic	13	20.9 12.2–35.8ROR 21.1 · χ² 226 / p 2e-51	20.1 EB05 12.1 · IC025 +2.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.9	no trial data cached
Circulatory collapse	18	18.8 11.9–29.8ROR 19.1 · χ² 286 / p 2e-64	18.3 EB05 12.0 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 12.3	no trial data cached
Hyperbilirubinaemia	10	17.4 9.4–32.2ROR 17.5 · χ² 138 / p 3e-32	15.9 EB05 8.1 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 10.4	no trial data cached
Premature delivery	15	16.8 10.1–27.7ROR 17.0 · χ² 207 / p 3e-47	16.0 EB05 9.7 · IC025 +2.6 3/3 methods agree	Not in label — unassessed	serious PRR 11.2	no trial data cached
Pulmonary mass	13	15.6 9.1–26.8ROR 15.8 · χ² 164 / p 9e-38	14.6 EB05 8.2 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious PRR 11.1	no trial data cached
Anaphylactic shock	22	15.3 10.1–23.2ROR 15.6 · χ² 281 / p 2e-63	14.9 EB05 10.0 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 10.0 · 91% clinician	no trial data cached
Hepatocellular injury	12	15.1 8.6–26.5ROR 15.2 · χ² 144 / p 2e-33	13.8 EB05 7.5 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 9.9	no trial data cached
Deafness	22	15.0 9.9–22.7ROR 15.3 · χ² 274 / p 8e-62	14.5 EB05 9.7 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 10.2	no trial data cached
Tubulointerstitial nephritis	13	12.4 7.2–21.3ROR 12.5 · χ² 125 / p 2e-29	10.9 EB05 6.1 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 8.1	no trial data cached
Anaphylactic reaction (severe allergic reaction)	38	12.4 9.0–16.9ROR 12.7 · χ² 386 / p 3e-86	12.0 EB05 8.9 · IC025 +2.9 3/3 methods agree	Labeled — boxed warning synonym match	serious PRR 8.2 · ♀ 76% (drug 56%) · 97% clinician	no trial data cached
Neurotoxicity	12	12.3 7.0–21.7ROR 12.5 · χ² 114 / p 6e-27	10.7 EB05 5.8 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 8.1	no trial data cached
Pancreatitis acute	14	11.2 6.7–18.9ROR 11.3 · χ² 120 / p 3e-28	9.8 EB05 5.7 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 7.3	no trial data cached
Premature baby	18	10.7 6.7–16.9ROR 10.8 · χ² 148 / p 2e-34	9.5 EB05 6.0 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 7.1	no trial data cached
Encephalopathy	14	10.2 6.1–17.2ROR 10.3 · χ² 107 / p 2e-25	8.7 EB05 5.2 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 6.7	no trial data cached
Electrocardiogram qt prolonged	20	9.9 6.4–15.3ROR 10.1 · χ² 152 / p 3e-35	8.9 EB05 5.8 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 6.6 · 95% clinician	no trial data cached
Thrombocytopenia (low platelets)	51	8.2 6.2–10.7ROR 8.5 · χ² 315 / p 7e-71	7.8 EB05 6.1 · IC025 +2.5 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 5.3 · ♀ 29% (drug 56%) · 96% clinician	no trial data cached
Transaminases increased	10	8.0 4.3–14.9ROR 8.1 · χ² 55 / p 6e-14	6.3 EB05 3.5 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 5.6	no trial data cached
Hepatitis (liver inflammation)	11	7.7 4.3–13.8ROR 7.7 · χ² 57 / p 2e-14	6.1 EB05 3.6 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 5.1	no trial data cached
Cardio-respiratory arrest	18	7.6 4.8–12.1ROR 7.7 · χ² 98 / p 3e-23	6.6 EB05 4.3 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 5.0	no trial data cached
Treatment failure	33	7.2 5.1–10.1ROR 7.4 · χ² 170 / p 3e-39	6.6 EB05 4.9 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 7.9 · 97% clinician	no trial data cached
Renal injury	11	6.5 3.6–11.8ROR 6.6 · χ² 46 / p 5e-12	5.3 EB05 3.1 · IC025 +1.4 3/3 methods agree	Not in label — unassessed	serious PRR 3.9	no trial data cached
Foetal exposure during pregnancy	17	3.7 2.3–6.0ROR 3.8 · χ² 32 / p 1e-8	3.4 EB05 2.3 · IC025 +1.0 3/3 methods agree	Reporting / coding artifact	serious PRR 2.5	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 resistance	83	57.9 47.0–71.3ROR 62.2 · χ² 4,575 / p <1e-300	57.0 EB05 47.4 · IC025 +5.1 3/3 methods agree	Reporting / coding artifact	serious PRR 27.5 · 98% clinician	no trial data cached
Drug reaction with eosinophilia and systemic symptoms	74	51.9 41.6–64.7ROR 55.3 · χ² 3,635 / p <1e-300	51.1 EB05 42.0 · IC025 +4.9 3/3 methods agree	Not in label — unassessed	serious PRR 33.8 · 96% clinician	no trial data cached
Thrombocytopenia (low platelets)	51	8.2 6.2–10.7ROR 8.5 · χ² 315 / p 7e-71	7.8 EB05 6.1 · IC025 +2.5 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 5.3 · ♀ 29% (drug 56%) · 96% clinician	no trial data cached
Anaphylactic reaction (severe allergic reaction)	38	12.4 9.0–16.9ROR 12.7 · χ² 386 / p 3e-86	12.0 EB05 8.9 · IC025 +2.9 3/3 methods agree	Labeled — boxed warning synonym match	serious PRR 8.2 · ♀ 76% (drug 56%) · 97% clinician	no trial data cached
Rash maculo-papular	36	29.1 21.1–40.1ROR 30.0 · χ² 947 / p 3e-208	28.6 EB05 21.6 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious PRR 19.8 · 100% clinician	no trial data cached
Treatment failure	33	7.2 5.1–10.1ROR 7.4 · χ² 170 / p 3e-39	6.6 EB05 4.9 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 7.9 · 97% clinician	no trial data cached
Deafness	22	15.0 9.9–22.7ROR 15.3 · χ² 274 / p 8e-62	14.5 EB05 9.7 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 10.2	no trial data cached
Anaphylactic shock	22	15.3 10.1–23.2ROR 15.6 · χ² 281 / p 2e-63	14.9 EB05 10.0 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 10.0 · 91% clinician	no trial data cached
Eosinophilia	21	21.5 14.1–32.8ROR 21.9 · χ² 390 / p 4e-87	21.1 EB05 14.4 · IC025 +3.1 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 10.5 · ♀ 30% (drug 56%) · 100% clinician	no trial data cached
Electrocardiogram qt prolonged	20	9.9 6.4–15.3ROR 10.1 · χ² 152 / p 3e-35	8.9 EB05 5.8 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 6.6 · 95% clinician	no trial data cached
Cardio-respiratory arrest	18	7.6 4.8–12.1ROR 7.7 · χ² 98 / p 3e-23	6.6 EB05 4.3 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 5.0	no trial data cached
Premature baby	18	10.7 6.7–16.9ROR 10.8 · χ² 148 / p 2e-34	9.5 EB05 6.0 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 7.1	no trial data cached
Circulatory collapse	18	18.8 11.9–29.8ROR 19.1 · χ² 286 / p 2e-64	18.3 EB05 12.0 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 12.3	no trial data cached
Foetal exposure during pregnancy	17	3.7 2.3–6.0ROR 3.8 · χ² 32 / p 1e-8	3.4 EB05 2.3 · IC025 +1.0 3/3 methods agree	Reporting / coding artifact	serious PRR 2.5	no trial data cached
Premature delivery	15	16.8 10.1–27.7ROR 17.0 · χ² 207 / p 3e-47	16.0 EB05 9.7 · IC025 +2.6 3/3 methods agree	Not in label — unassessed	serious PRR 11.2	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.

Drug reaction with eosinophilia and systemic symptoms — n=74, PRR 51.9
Rash maculo-papular — n=36, PRR 29.1
Anaphylactic shock — n=22, PRR 15.3
Deafness — n=22, PRR 15.0
Electrocardiogram qt prolonged — n=20, PRR 9.9

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 Cefoxitin?

In FDA FAERS, the most frequently co-reported reaction terms for Cefoxitin are drug reaction with eosinophilia and systemic symptoms, thrombocytopenia, anaphylactic reaction, rash maculo-papular, deafness, anaphylactic shock. 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 Cefoxitin have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: PHARMACY BULK PACKAGE – NOT FOR DIRECT INFUSION

Do FAERS signals prove that Cefoxitin 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 4c6f7665-204f-6c69-7669-61204d756e6e, effective 20200609; matched on openfda.generic_name.exact:"CEFOXITIN")
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, field patient.drug.openfda.generic_name.exact, 39 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.