Benzocaine side effects: what 1,003 FDA adverse event reports show

Benzocaine · Defend · 39 reaction terms · 510 drug–reaction co-reports · data 2026-09-14

Drug class

Standardized Chemical Allergen

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Defend

openFDA label

Who reports

1,003 reports · 74% serious · 77 with death outcome · 63% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Use For oral mucosal use only, as directed by dentist. For the temporary relief of pain due to minor dental procedures

FDA label, Indications and Usage

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 18 strongest signals

Reporting / coding artifact 3Lab value / disease marker 1No label text to screen 14

What the badges mean

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.
No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.

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. 21 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
Autoimmune disorder	23	50.3 33.6–75.4ROR 51.5 · χ² 1,062 / p 4e-233	48.3 EB05 33.9 · IC025 +3.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 41.9 · 100% clinician	no trial data cached
Cyanosis (blue skin from low oxygen)	35	46.5 33.6–64.4ROR 48.2 · χ² 1,512 / p <1e-300	45.4 EB05 34.1 · IC025 +4.3 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 36.2	no trial data cached
Bursitis	25	43.4 29.5–63.9ROR 44.5 · χ² 992 / p 5e-218	42.0 EB05 29.9 · IC025 +3.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 39.7 · 96% clinician	no trial data cached
Hypoxia (low oxygen)	27	16.1 11.1–23.4ROR 16.5 · χ² 368 / p 3e-82	15.8 EB05 11.2 · IC025 +3.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.3 · 92% clinician	no trial data cached
End stage renal disease	14	15.9 9.4–26.8ROR 16.1 · χ² 181 / p 2e-41	15.0 EB05 8.8 · IC025 +2.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.4	no trial data cached
Paraesthesia oral	10	14.6 7.9–27.0ROR 14.7 · χ² 113 / p 1e-26	12.8 EB05 6.4 · IC025 +2.1 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 20.2	no trial data cached
Respiratory distress	19	14.4 9.2–22.5ROR 14.7 · χ² 224 / p 7e-51	13.7 EB05 8.8 · IC025 +2.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.4	no trial data cached
Hypoaesthesia oral	10	13.9 7.5–25.7ROR 14.0 · χ² 107 / p 2e-25	12.0 EB05 6.0 · IC025 +2.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 13.9	no trial data cached
Blood cholesterol increased	25	11.2 7.6–16.5ROR 11.5 · χ² 223 / p 1e-50	10.5 EB05 7.1 · IC025 +2.6 3/3 methods agree	Lab value / disease marker	serious PRR 13.2 · 100% clinician	no trial data cached
Amnesia (memory loss)	33	10.6 7.6–14.8ROR 10.9 · χ² 277 / p 2e-62	10.0 EB05 7.2 · IC025 +2.6 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.1 · ♀ 100% (drug 63%) · 94% clinician	no trial data cached
Blister	27	10.1 6.9–14.6ROR 10.3 · χ² 212 / p 2e-48	9.3 EB05 6.5 · IC025 +2.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.5 · ♀ 100% (drug 63%) · 96% clinician	no trial data cached
Medication error	26	9.8 6.7–14.3ROR 10.0 · χ² 197 / p 4e-45	9.0 EB05 6.2 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 10.9 · 96% clinician	no trial data cached
Arthropathy	24	9.0 6.1–13.4ROR 9.2 · χ² 163 / p 1e-37	8.1 EB05 5.6 · IC025 +2.3 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 8.5 · 92% clinician	no trial data cached
Lip swelling	14	8.8 5.2–14.8ROR 8.9 · χ² 89 / p 2e-21	7.4 EB05 4.5 · IC025 +1.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 10.2	no trial data cached
Swelling face	27	8.7 6.0–12.6ROR 8.9 · χ² 176 / p 1e-40	7.9 EB05 5.6 · IC025 +2.3 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 9.5	no trial data cached
Mucosal inflammation	10	8.0 4.3–14.9ROR 8.1 · χ² 55 / p 7e-14	6.3 EB05 3.5 · IC025 +1.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 6.6	no trial data cached
Exposure during pregnancy	20	6.7 4.4–10.4ROR 6.8 · χ² 92 / p 4e-22	5.9 EB05 4.0 · IC025 +1.8 3/3 methods agree	Reporting / coding artifact	serious PRR 7.1 · 90% clinician	no trial data cached
Maternal exposure during pregnancy	23	5.5 3.6–8.2ROR 5.6 · χ² 80 / p 2e-19	4.9 EB05 3.5 · IC025 +1.6 3/3 methods agree	Reporting / coding artifact	serious PRR 5.4 · 96% clinician	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
Cyanosis (blue skin from low oxygen)	35	46.5 33.6–64.4ROR 48.2 · χ² 1,512 / p <1e-300	45.4 EB05 34.1 · IC025 +4.3 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 36.2	no trial data cached
Amnesia (memory loss)	33	10.6 7.6–14.8ROR 10.9 · χ² 277 / p 2e-62	10.0 EB05 7.2 · IC025 +2.6 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.1 · ♀ 100% (drug 63%) · 94% clinician	no trial data cached
Swelling face	27	8.7 6.0–12.6ROR 8.9 · χ² 176 / p 1e-40	7.9 EB05 5.6 · IC025 +2.3 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 9.5	no trial data cached
Blister	27	10.1 6.9–14.6ROR 10.3 · χ² 212 / p 2e-48	9.3 EB05 6.5 · IC025 +2.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.5 · ♀ 100% (drug 63%) · 96% clinician	no trial data cached
Hypoxia (low oxygen)	27	16.1 11.1–23.4ROR 16.5 · χ² 368 / p 3e-82	15.8 EB05 11.2 · IC025 +3.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.3 · 92% clinician	no trial data cached
Medication error	26	9.8 6.7–14.3ROR 10.0 · χ² 197 / p 4e-45	9.0 EB05 6.2 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 10.9 · 96% clinician	no trial data cached
Blood cholesterol increased	25	11.2 7.6–16.5ROR 11.5 · χ² 223 / p 1e-50	10.5 EB05 7.1 · IC025 +2.6 3/3 methods agree	Lab value / disease marker	serious PRR 13.2 · 100% clinician	no trial data cached
Bursitis	25	43.4 29.5–63.9ROR 44.5 · χ² 992 / p 5e-218	42.0 EB05 29.9 · IC025 +3.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 39.7 · 96% clinician	no trial data cached
Arthropathy	24	9.0 6.1–13.4ROR 9.2 · χ² 163 / p 1e-37	8.1 EB05 5.6 · IC025 +2.3 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 8.5 · 92% clinician	no trial data cached
Maternal exposure during pregnancy	23	5.5 3.6–8.2ROR 5.6 · χ² 80 / p 2e-19	4.9 EB05 3.5 · IC025 +1.6 3/3 methods agree	Reporting / coding artifact	serious PRR 5.4 · 96% clinician	no trial data cached
Autoimmune disorder	23	50.3 33.6–75.4ROR 51.5 · χ² 1,062 / p 4e-233	48.3 EB05 33.9 · IC025 +3.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 41.9 · 100% clinician	no trial data cached
Exposure during pregnancy	20	6.7 4.4–10.4ROR 6.8 · χ² 92 / p 4e-22	5.9 EB05 4.0 · IC025 +1.8 3/3 methods agree	Reporting / coding artifact	serious PRR 7.1 · 90% clinician	no trial data cached
Respiratory distress	19	14.4 9.2–22.5ROR 14.7 · χ² 224 / p 7e-51	13.7 EB05 8.8 · IC025 +2.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 11.4	no trial data cached
Lip swelling	14	8.8 5.2–14.8ROR 8.9 · χ² 89 / p 2e-21	7.4 EB05 4.5 · IC025 +1.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 10.2	no trial data cached
End stage renal disease	14	15.9 9.4–26.8ROR 16.1 · χ² 181 / p 2e-41	15.0 EB05 8.8 · IC025 +2.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 12.4	no trial data cached

Unlabeled candidate signals

Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.

✓ A hand-written Bradford Hill causality assessment exists for this drug: Benzocaine ↔ Methaemoglobinaemia.

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 Benzocaine?

In FDA FAERS, the most frequently co-reported reaction terms for Benzocaine are cyanosis, amnesia, swelling face, blister, hypoxia, blood cholesterol increased. 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 Benzocaine have an FDA boxed warning?

No. The FDA label retrieved for Benzocaine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Benzocaine 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 0301c1bc-db48-4635-97f5-9eaef7ab9579, effective 20250116; matched on openfda.generic_name.exact:"BENZOCAINE")
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.