Drug · FAERS side-effect profile with label screen
Hydralazine side effects: what 2,614 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Hydralazine Hydrochloride (Hydralazine 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
2,614 reports · 81% serious · 204 with death outcome · 59% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Essential hypertension, alone or as an adjunct.
FDA label, Indications and Usage
What it is
DESCRIPTION HydrALAZINE hydrochloride, USP, is an antihypertensive, for oral administration.
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 1Labeled (related wording) 1Likely indication confounding 2Reporting / coding artifact 5Lab value / disease marker 3Not in label — unassessed 28
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. 52 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 |
|---|---|---|---|---|---|---|
| Hepatic steatosis | 96 | 41.6 34.2–50.6ROR 43.1 · χ² 3,747 / p <1e-300 | 41.1 EB05 34.6 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious PRR 33.7 · ♀ 99% (drug 59%) | no trial data cached |
| Vasculitis | 58 | 40.1 31.1–51.8ROR 41.0 · χ² 2,163 / p <1e-300 | 39.4 EB05 31.6 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious PRR 30.1 · 96% clinician | no trial data cached |
| Contraindicated product administered | 81 | 21.6 17.4–26.8ROR 22.3 · χ² 1,568 / p <1e-300 | 21.4 EB05 17.8 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 17.5 · ♀ 90% (drug 59%) | no trial data cached |
| Gout | 40 | 17.9 13.2–24.3ROR 18.2 · χ² 620 / p 3e-137 | 17.7 EB05 13.5 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 18.3 · ♀ 90% (drug 59%) | no trial data cached |
| Therapeutic product effect decreased | 94 | 17.0 14.0–20.8ROR 17.6 · χ² 1,402 / p <1e-300 | 16.9 EB05 14.2 · IC025 +3.6 3/3 methods agree | Reporting / coding artifact | serious PRR 23.7 · ♀ 100% (drug 59%) | no trial data cached |
| End stage renal disease | 37 | 16.1 11.7–22.2ROR 16.4 · χ² 510 / p 3e-113 | 15.9 EB05 11.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 11.5 | no trial data cached |
| Haematuria (blood in urine) | 61 | 14.3 11.1–18.3ROR 14.6 · χ² 741 / p 2e-163 | 14.1 EB05 11.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 · ♀ 91% (drug 59%) | no trial data cached |
| Cardiac failure congestive | 131 | 13.0 11.0–15.3ROR 13.6 · χ² 1,439 / p <1e-300 | 12.9 EB05 11.1 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 9.3 · ♀ 88% (drug 59%) | no trial data cached |
| Systemic lupus erythematosus | 52 | 11.8 9.0–15.5ROR 12.0 · χ² 504 / p 7e-112 | 11.5 EB05 9.0 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.5 · 96% clinician | no trial data cached |
| Pericardial effusion | 32 | 11.2 7.9–15.8ROR 11.3 · χ² 286 / p 2e-64 | 10.6 EB05 7.6 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 · 100% clinician | no trial data cached |
| Hyperkalaemia (high potassium) | 48 | 11.0 8.3–14.6ROR 11.2 · χ² 429 / p 2e-95 | 10.7 EB05 8.2 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 · ♀ 85% (drug 59%) | no trial data cached |
| Liver disorder | 60 | 10.9 8.5–14.0ROR 11.1 · χ² 529 / p 3e-117 | 10.6 EB05 8.4 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 9.2 · ♀ 98% (drug 59%) | no trial data cached |
| Dialysis | 19 | 10.7 6.9–16.8ROR 10.8 · χ² 158 / p 2e-36 | 9.7 EB05 6.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 | no trial data cached |
| Gastric disorder | 46 | 10.6 8.0–14.1ROR 10.8 · χ² 391 / p 3e-87 | 10.2 EB05 7.8 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 15.8 · ♀ 98% (drug 59%) | no trial data cached |
| Blood potassium increased | 19 | 9.4 6.0–14.7ROR 9.5 · χ² 134 / p 2e-31 | 8.3 EB05 5.4 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 6.0 | no trial data cached |
| Hypertensive crisis | 13 | 9.3 5.4–16.1ROR 9.4 · χ² 89 / p 2e-21 | 7.8 EB05 4.6 · IC025 +1.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 6.7 | no trial data cached |
| Premature delivery | 18 | 9.0 5.7–14.3ROR 9.1 · χ² 121 / p 2e-28 | 7.9 EB05 5.1 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Exposure during pregnancy | 69 | 8.9 7.1–11.2ROR 9.1 · χ² 478 / p 4e-106 | 8.6 EB05 7.0 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 2.8 · ♀ 100% (drug 59%) · 96% clinician | no trial data cached |
| Renal impairment | 90 | 8.6 7.0–10.6ROR 8.9 · χ² 602 / p 3e-133 | 8.4 EB05 7.0 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · ♀ 86% (drug 59%) | no trial data cached |
| Cardiac failure (heart failure) | 86 | 8.6 7.0–10.6ROR 8.9 · χ² 571 / p 2e-126 | 8.3 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · ♀ 93% (drug 59%) | no trial data cached |
| Tubulointerstitial nephritis | 17 | 7.3 4.5–11.7ROR 7.3 · χ² 86 / p 9e-21 | 6.3 EB05 4.1 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 138 | 7.3 6.2–8.6ROR 7.6 · χ² 745 / p 2e-164 | 7.1 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 · 94% clinician | no trial data cached |
| Premature baby | 27 | 7.2 4.9–10.4ROR 7.2 · χ² 138 / p 5e-32 | 6.5 EB05 4.7 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Hypertension (high blood pressure) | 187 | 7.1 6.2–8.1ROR 7.5 · χ² 979 / p 3e-215 | 7.0 EB05 6.2 · IC025 +2.6 3/3 methods agree | Likely indication confounding term in indications | serious PRR 5.9 · ♀ 81% (drug 59%) | no trial data cached |
| Hepatic enzyme increased | 59 | 7.0 5.4–9.0ROR 7.1 · χ² 296 / p 1e-66 | 6.7 EB05 5.3 · IC025 +2.3 3/3 methods agree | Lab value / disease marker | serious PRR 7.0 · ♀ 96% (drug 59%) | no trial data cached |
| Blood pressure abnormal | 17 | 6.9 4.3–11.1ROR 6.9 · χ² 80 / p 2e-19 | 5.9 EB05 3.9 · IC025 +1.7 3/3 methods agree | Lab value / disease marker | serious PRR 4.2 | no trial data cached |
| Abdominal discomfort | 136 | 6.5 5.5–7.7ROR 6.8 · χ² 636 / p 1e-140 | 6.4 EB05 5.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 · ♀ 83% (drug 59%) | no trial data cached |
| Drug intolerance | 75 | 6.3 5.0–7.8ROR 6.4 · χ² 327 / p 2e-73 | 6.0 EB05 5.0 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 7.1 · ♀ 100% (drug 59%) | no trial data cached |
| Drug-induced liver injury | 24 | 6.2 4.2–9.3ROR 6.3 · χ² 101 / p 6e-24 | 5.6 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 100% clinician | no trial data cached |
| Ascites | 22 | 6.0 4.0–9.1ROR 6.0 · χ² 87 / p 6e-21 | 5.4 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | no trial data cached |
| Proteinuria | 14 | 6.0 3.5–10.1ROR 6.0 · χ² 53 / p 2e-13 | 5.1 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Skin reaction | 10 | 5.7 3.1–10.6ROR 5.7 · χ² 34 / p 2e-9 | 4.6 EB05 2.7 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Gastrointestinal disorder | 60 | 5.4 4.2–7.0ROR 5.6 · χ² 214 / p 8e-49 | 5.2 EB05 4.2 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 · ♀ 92% (drug 59%) | no trial data cached |
| Photosensitivity reaction (sun sensitivity) | 11 | 5.4 3.0–9.7ROR 5.4 · χ² 35 / p 2e-9 | 4.5 EB05 2.7 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.1 | no trial data cached |
| Chronic kidney disease | 48 | 5.0 3.8–6.7ROR 5.1 · χ² 151 / p 5e-35 | 4.8 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 | no trial data cached |
| Maternal exposure during pregnancy | 53 | 4.8 3.7–6.3ROR 4.9 · χ² 157 / p 2e-36 | 4.6 EB05 3.7 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 3.8 · ♀ 96% (drug 59%) | no trial data cached |
| Drug hypersensitivity | 112 | 4.6 3.9–5.5ROR 4.8 · χ² 318 / p 2e-71 | 4.5 EB05 3.9 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.5 · ♀ 94% (drug 59%) | no trial data cached |
| Respiratory failure | 42 | 4.6 3.4–6.2ROR 4.7 · χ² 116 / p 3e-27 | 4.4 EB05 3.4 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 · 95% clinician | no trial data cached |
| Abdominal pain upper | 111 | 4.3 3.6–5.2ROR 4.5 · χ² 284 / p 5e-64 | 4.3 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 · ♀ 98% (drug 59%) | no trial data cached |
| Cough | 141 | 4.0 3.4–4.7ROR 4.2 · χ² 324 / p 9e-73 | 4.0 EB05 3.5 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 · ♀ 88% (drug 59%) | 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 |
|---|---|---|---|---|---|---|
| Hypertension (high blood pressure) | 187 | 7.1 6.2–8.1ROR 7.5 · χ² 979 / p 3e-215 | 7.0 EB05 6.2 · IC025 +2.6 3/3 methods agree | Likely indication confounding term in indications | serious PRR 5.9 · ♀ 81% (drug 59%) | no trial data cached |
| Cough | 141 | 4.0 3.4–4.7ROR 4.2 · χ² 324 / p 9e-73 | 4.0 EB05 3.5 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 · ♀ 88% (drug 59%) | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 138 | 7.3 6.2–8.6ROR 7.6 · χ² 745 / p 2e-164 | 7.1 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 · 94% clinician | no trial data cached |
| Abdominal discomfort | 136 | 6.5 5.5–7.7ROR 6.8 · χ² 636 / p 1e-140 | 6.4 EB05 5.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 · ♀ 83% (drug 59%) | no trial data cached |
| Cardiac failure congestive | 131 | 13.0 11.0–15.3ROR 13.6 · χ² 1,439 / p <1e-300 | 12.9 EB05 11.1 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 9.3 · ♀ 88% (drug 59%) | no trial data cached |
| Drug hypersensitivity | 112 | 4.6 3.9–5.5ROR 4.8 · χ² 318 / p 2e-71 | 4.5 EB05 3.9 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.5 · ♀ 94% (drug 59%) | no trial data cached |
| Abdominal pain upper | 111 | 4.3 3.6–5.2ROR 4.5 · χ² 284 / p 5e-64 | 4.3 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 · ♀ 98% (drug 59%) | no trial data cached |
| Hepatic steatosis | 96 | 41.6 34.2–50.6ROR 43.1 · χ² 3,747 / p <1e-300 | 41.1 EB05 34.6 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious PRR 33.7 · ♀ 99% (drug 59%) | no trial data cached |
| Therapeutic product effect decreased | 94 | 17.0 14.0–20.8ROR 17.6 · χ² 1,402 / p <1e-300 | 16.9 EB05 14.2 · IC025 +3.6 3/3 methods agree | Reporting / coding artifact | serious PRR 23.7 · ♀ 100% (drug 59%) | no trial data cached |
| Renal impairment | 90 | 8.6 7.0–10.6ROR 8.9 · χ² 602 / p 3e-133 | 8.4 EB05 7.0 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · ♀ 86% (drug 59%) | no trial data cached |
| Cardiac failure (heart failure) | 86 | 8.6 7.0–10.6ROR 8.9 · χ² 571 / p 2e-126 | 8.3 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · ♀ 93% (drug 59%) | no trial data cached |
| Contraindicated product administered | 81 | 21.6 17.4–26.8ROR 22.3 · χ² 1,568 / p <1e-300 | 21.4 EB05 17.8 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 17.5 · ♀ 90% (drug 59%) | no trial data cached |
| Drug intolerance | 75 | 6.3 5.0–7.8ROR 6.4 · χ² 327 / p 2e-73 | 6.0 EB05 5.0 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 7.1 · ♀ 100% (drug 59%) | no trial data cached |
| Exposure during pregnancy | 69 | 8.9 7.1–11.2ROR 9.1 · χ² 478 / p 4e-106 | 8.6 EB05 7.0 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 2.8 · ♀ 100% (drug 59%) · 96% clinician | no trial data cached |
| Hospitalisation | 63 | 3.3 2.6–4.2ROR 3.4 · χ² 100 / p 6e-24 | 3.3 EB05 2.6 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 2.4 | 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 steatosis — n=96, PRR 41.6
- Vasculitis — n=58, PRR 40.1
- Gout — n=40, PRR 17.9
- End stage renal disease — n=37, PRR 16.1
- Haematuria — n=61, PRR 14.3
- Cardiac failure congestive — n=131, PRR 13.0
- Pericardial effusion — n=32, PRR 11.2
- Hyperkalaemia — n=48, PRR 11.0
- Liver disorder — n=60, PRR 10.9
- Gastric disorder — n=46, PRR 10.6
✓ A hand-written Bradford Hill causality assessment exists for this drug: Hydralazine ↔ Drug-induced lupus.
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 Hydralazine?
In FDA FAERS, the most frequently co-reported reaction terms for Hydralazine are hypertension, cough, acute kidney injury, abdominal discomfort, cardiac failure congestive, drug hypersensitivity. 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 Hydralazine have an FDA boxed warning?
No. The FDA label retrieved for Hydralazine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Hydralazine 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 0c7f9bd0-6c0a-4521-b77a-3582faa96874, effective 20251210; matched on
openfda.generic_name.exact:"HYDRALAZINE 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, 92 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.