Drug · FAERS side-effect profile with label screen
Ethambutol side effects: what 2,666 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Ethambutol Hydrochloride (Ethambutol Hydrochloride)
closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match
Who reports
2,666 reports · 82% serious · 331 with death outcome · 52% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Ethambutol Hydrochloride Tablets, USP are indicated for the treatment of pulmonary tuberculosis. It should not be used as the sole antituberculous drug, but should be used in conjunction with at least one other antituberculous drug. Selection of the companion drug should be based on clinical experience, considerations of comparative safety, and appropriate in vitro susceptibility studies.
FDA label, Indications and Usage
What it is
DESCRIPTION Ethambutol hydrochloride is an oral chemotherapeutic agent which is specifically effective against actively growing microorganisms of the genus Mycobacterium, including M. tuberculosis. Ethambutol hydrochloride is a white, crystalline powder.
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 4Labeled (related wording) 3Likely indication confounding 1Reporting / coding artifact 4Lab value / disease marker 3Not in label — unassessed 25
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. 57 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 |
|---|---|---|---|---|---|---|
| Tuberculosis | 58 | 35.6 27.6–45.9ROR 36.3 · χ² 1,906 / p <1e-300 | 35.0 EB05 28.1 · IC025 +4.3 3/3 methods agree | Likely indication confounding term in indications | serious PRR 25.4 | no trial data cached |
| Hepatic cytolysis | 50 | 32.2 24.5–42.5ROR 32.8 · χ² 1,478 / p <1e-300 | 31.8 EB05 25.0 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 22.6 · 100% clinician | no trial data cached |
| Acute hepatic failure | 36 | 20.8 15.1–28.8ROR 21.1 · χ² 659 / p 1e-145 | 20.6 EB05 15.5 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 14.6 · 100% clinician | no trial data cached |
| Hepatic encephalopathy | 23 | 19.4 12.9–29.1ROR 19.5 · χ² 382 / p 2e-85 | 19.0 EB05 13.2 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 13.7 · ♀ 74% (drug 52%) · 100% clinician | no trial data cached |
| Hepatotoxicity (liver damage) | 52 | 18.5 14.1–24.2ROR 18.8 · χ² 840 / p 5e-185 | 18.3 EB05 14.5 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 13.0 · ♀ 72% (drug 52%) · 93% clinician | no trial data cached |
| Hepatitis (liver inflammation) | 58 | 17.8 13.8–23.0ROR 18.2 · χ² 903 / p 9e-199 | 17.7 EB05 14.2 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.8 · 93% clinician | no trial data cached |
| Rash maculo-papular | 49 | 17.4 13.2–23.0ROR 17.7 · χ² 740 / p 3e-163 | 17.2 EB05 13.5 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 · 100% clinician | no trial data cached |
| Toxic epidermal necrolysis (severe skin peeling reaction) | 27 | 14.1 9.7–20.5ROR 14.2 · χ² 315 / p 1e-70 | 13.6 EB05 9.6 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 9.9 · ♀ 19% (drug 52%) · 96% clinician | no trial data cached |
| Drug resistance | 41 | 12.5 9.3–17.0ROR 12.7 · χ² 424 / p 2e-94 | 12.2 EB05 9.2 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 5.6 | no trial data cached |
| Jaundice (yellowing of skin/eyes) | 38 | 11.1 8.1–15.2ROR 11.2 · χ² 338 / p 9e-76 | 10.6 EB05 7.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 · 91% clinician | no trial data cached |
| Drug-induced liver injury | 43 | 11.0 8.1–14.7ROR 11.1 · χ² 379 / p 9e-85 | 10.5 EB05 8.0 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Hyperbilirubinaemia | 14 | 10.7 6.3–18.0ROR 10.7 · χ² 113 / p 1e-26 | 9.2 EB05 5.4 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Drug ineffective for unapproved indication | 74 | 10.4 8.3–13.1ROR 10.7 · χ² 623 / p 1e-137 | 10.2 EB05 8.3 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 0.4 | no trial data cached |
| Hepatomegaly | 13 | 10.3 6.0–17.8ROR 10.4 · χ² 101 / p 6e-24 | 8.7 EB05 5.0 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 7.3 | no trial data cached |
| Eosinophilia | 23 | 10.3 6.9–15.5ROR 10.4 · χ² 185 / p 2e-42 | 9.5 EB05 6.4 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.3 · 100% clinician | no trial data cached |
| Hepatocellular injury | 17 | 9.4 5.8–15.1ROR 9.4 · χ² 119 / p 5e-28 | 8.2 EB05 5.2 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Drug eruption | 21 | 9.4 6.1–14.3ROR 9.4 · χ² 149 / p 2e-34 | 8.4 EB05 5.6 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.5 | no trial data cached |
| Cholestasis (bile flow blockage) | 22 | 9.1 6.0–13.7ROR 9.1 · χ² 150 / p 1e-34 | 8.1 EB05 5.5 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Drug intolerance | 105 | 8.6 7.1–10.3ROR 8.9 · χ² 697 / p 6e-154 | 8.4 EB05 7.1 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 2.0 | no trial data cached |
| Drug reaction with eosinophilia and systemic symptoms | 26 | 8.0 5.5–11.7ROR 8.1 · χ² 152 / p 3e-35 | 7.2 EB05 5.1 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.6 · 96% clinician | no trial data cached |
| Aphonia | 14 | 7.9 4.7–13.3ROR 7.9 · χ² 77 / p 7e-19 | 6.6 EB05 4.1 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 | no trial data cached |
| Oral candidiasis (oral thrush) | 13 | 7.9 4.6–13.5ROR 7.9 · χ² 71 / p 2e-17 | 6.5 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.7 | no trial data cached |
| Lymphopenia | 14 | 7.8 4.6–13.2ROR 7.9 · χ² 77 / p 1e-18 | 6.5 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Malnutrition | 11 | 7.8 4.3–14.0ROR 7.8 · χ² 58 / p 1e-14 | 6.2 EB05 3.6 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Lymphadenopathy | 35 | 7.8 5.6–10.8ROR 7.9 · χ² 200 / p 1e-45 | 7.2 EB05 5.3 · IC025 +2.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.0 | no trial data cached |
| Uveitis | 13 | 7.6 4.4–13.0ROR 7.6 · χ² 68 / p 1e-16 | 6.2 EB05 3.8 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 | no trial data cached |
| Ventricular extrasystoles | 10 | 7.6 4.1–14.0ROR 7.6 · χ² 50 / p 6e-13 | 5.9 EB05 3.4 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Pancytopenia (all blood cells low) | 53 | 7.5 5.7–9.8ROR 7.6 · χ² 291 / p 1e-65 | 7.1 EB05 5.6 · IC025 +2.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.3 · 98% clinician | no trial data cached |
| Transaminases increased | 21 | 7.4 4.8–11.4ROR 7.5 · χ² 110 / p 4e-26 | 6.6 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 · 90% clinician | no trial data cached |
| Productive cough (cough with phlegm) | 42 | 7.0 5.2–9.4ROR 7.1 · χ² 209 / p 1e-47 | 6.5 EB05 5.0 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Blood alkaline phosphatase increased | 22 | 6.9 4.6–10.5ROR 7.0 · χ² 106 / p 3e-25 | 6.2 EB05 4.3 · IC025 +1.9 3/3 methods agree | Lab value / disease marker | serious PRR 5.4 | no trial data cached |
| Product use in unapproved indication | 213 | 6.9 6.0–7.8ROR 7.4 · χ² 1,070 / p 6e-235 | 6.8 EB05 6.0 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 3.5 | no trial data cached |
| Haemoptysis | 24 | 6.7 4.5–10.0ROR 6.8 · χ² 112 / p 2e-26 | 6.1 EB05 4.3 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Blindness | 34 | 6.6 4.7–9.2ROR 6.6 · χ² 155 / p 7e-36 | 6.1 EB05 4.5 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.3 | no trial data cached |
| Blood bilirubin increased | 22 | 6.4 4.2–9.7ROR 6.4 · χ² 95 / p 1e-22 | 5.7 EB05 3.9 · IC025 +1.8 3/3 methods agree | Lab value / disease marker | serious PRR 4.5 · 95% clinician | no trial data cached |
| Agranulocytosis (severe loss of white cells) | 15 | 6.4 3.8–10.6ROR 6.4 · χ² 63 / p 1e-15 | 5.4 EB05 3.5 · IC025 +1.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.5 | no trial data cached |
| Visual acuity reduced | 27 | 6.3 4.4–9.2ROR 6.4 · χ² 116 / p 2e-27 | 5.8 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
| Drug toxicity | 11 | 6.3 3.5–11.3ROR 6.3 · χ² 43 / p 2e-11 | 5.1 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Alanine aminotransferase increased | 48 | 6.1 4.6–8.1ROR 6.2 · χ² 202 / p 4e-46 | 5.8 EB05 4.6 · IC025 +2.1 3/3 methods agree | Lab value / disease marker | serious PRR 4.7 · 98% clinician | no trial data cached |
| Disseminated intravascular coagulation | 11 | 6.1 3.4–11.0ROR 6.1 · χ² 42 / p 4e-11 | 5.0 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | 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 |
|---|---|---|---|---|---|---|
| Product use in unapproved indication | 213 | 6.9 6.0–7.8ROR 7.4 · χ² 1,070 / p 6e-235 | 6.8 EB05 6.0 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 3.5 | no trial data cached |
| Drug interaction | 115 | 5.7 4.8–6.8ROR 5.9 · χ² 443 / p 1e-98 | 5.6 EB05 4.8 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 4.1 | no trial data cached |
| Drug intolerance | 105 | 8.6 7.1–10.3ROR 8.9 · χ² 697 / p 6e-154 | 8.4 EB05 7.1 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 2.0 | no trial data cached |
| Drug ineffective for unapproved indication | 74 | 10.4 8.3–13.1ROR 10.7 · χ² 623 / p 1e-137 | 10.2 EB05 8.3 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 0.4 | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 64 | 3.7 2.9–4.7ROR 3.8 · χ² 125 / p 3e-29 | 3.6 EB05 2.9 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.6 · 97% clinician | no trial data cached |
| Hepatitis (liver inflammation) | 58 | 17.8 13.8–23.0ROR 18.2 · χ² 903 / p 9e-199 | 17.7 EB05 14.2 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.8 · 93% clinician | no trial data cached |
| Tuberculosis | 58 | 35.6 27.6–45.9ROR 36.3 · χ² 1,906 / p <1e-300 | 35.0 EB05 28.1 · IC025 +4.3 3/3 methods agree | Likely indication confounding term in indications | serious PRR 25.4 | no trial data cached |
| Pancytopenia (all blood cells low) | 53 | 7.5 5.7–9.8ROR 7.6 · χ² 291 / p 1e-65 | 7.1 EB05 5.6 · IC025 +2.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.3 · 98% clinician | no trial data cached |
| Hepatotoxicity (liver damage) | 52 | 18.5 14.1–24.2ROR 18.8 · χ² 840 / p 5e-185 | 18.3 EB05 14.5 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 13.0 · ♀ 72% (drug 52%) · 93% clinician | no trial data cached |
| Hepatic cytolysis | 50 | 32.2 24.5–42.5ROR 32.8 · χ² 1,478 / p <1e-300 | 31.8 EB05 25.0 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 22.6 · 100% clinician | no trial data cached |
| Rash maculo-papular | 49 | 17.4 13.2–23.0ROR 17.7 · χ² 740 / p 3e-163 | 17.2 EB05 13.5 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 · 100% clinician | no trial data cached |
| Alanine aminotransferase increased | 48 | 6.1 4.6–8.1ROR 6.2 · χ² 202 / p 4e-46 | 5.8 EB05 4.6 · IC025 +2.1 3/3 methods agree | Lab value / disease marker | serious PRR 4.7 · 98% clinician | no trial data cached |
| Drug-induced liver injury | 43 | 11.0 8.1–14.7ROR 11.1 · χ² 379 / p 9e-85 | 10.5 EB05 8.0 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Productive cough (cough with phlegm) | 42 | 7.0 5.2–9.4ROR 7.1 · χ² 209 / p 1e-47 | 6.5 EB05 5.0 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Drug resistance | 41 | 12.5 9.3–17.0ROR 12.7 · χ² 424 / p 2e-94 | 12.2 EB05 9.2 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 5.6 | 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.
- Hepatic cytolysis — n=50, PRR 32.2
- Acute hepatic failure — n=36, PRR 20.8
- Hepatic encephalopathy — n=23, PRR 19.4
- Hepatotoxicity — n=52, PRR 18.5
- Rash maculo-papular — n=49, PRR 17.4
- Toxic epidermal necrolysis — n=27, PRR 14.1
- Jaundice — n=38, PRR 11.1
- Drug-induced liver injury — n=43, PRR 11.0
- Drug eruption — n=21, PRR 9.4
- Cholestasis — n=22, PRR 9.1
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 Ethambutol?
In FDA FAERS, the most frequently co-reported reaction terms for Ethambutol are neutropenia, hepatitis, tuberculosis, pancytopenia, hepatotoxicity, hepatic cytolysis. 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 Ethambutol have an FDA boxed warning?
No. The FDA label retrieved for Ethambutol has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Ethambutol 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 08decdf3-a397-42e7-8ac3-e489c0cc7085, effective 20231108; matched on
openfda.generic_name.exact:"ETHAMBUTOL HYDROCHLORIDE") - 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, 97 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.