Drug · FAERS side-effect profile with label screen
Hydrochlorothiazide side effects: what 144,362 FDA adverse event reports show
Who reports
144,362 reports · 67% serious · 10,118 with death outcome · 64% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Hydrochlorothiazide tablets are indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. Hydrochlorothiazide has also been found useful in edema due to various forms of renal dysfunction such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.
FDA label, Indications and Usage
What it is
Hydrochlorothiazide is a benzothiadiazine that is 3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide substituted by a chloro group at position 6 and a sulfonamide at 7.
PubChem CID 3639 (ChEBI)
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) 3Likely indication confounding 2Lab value / disease marker 4Not in label — unassessed 30
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.
- 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, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,126 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 |
|---|---|---|---|---|---|---|
| Cardiospasm | 398 | 370.1 307.2–446.0ROR 371.2 · calibrated p 2e-12 ✓ | 103.0 EB05 94.8 · IC025 +6.4 3/3 methods agree vs other Thiazide Diuretics: only this drug | Likely indication confounding shares a disease stem with the indications wording | serious n=398 | not reported in cached trials |
| Vaginal flatulence | 188 | 234.7 186.0–296.1ROR 235.0 · calibrated p 2e-10 ✓ | 88.4 EB05 78.3 · IC025 +5.9 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=188 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Immunisation | 257 | 213.9 176.3–259.5ROR 214.2 · calibrated p 3e-10 ✓ | 85.5 EB05 77.1 · IC025 +6.0 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=257 | not reported in cached trials |
| Palmoplantar keratoderma | 386 | 169.0 145.8–195.8ROR 169.4 · calibrated p 2e-9 ✓ | 77.5 EB05 71.2 · IC025 +6.0 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=386 | not reported in cached trials |
| Neurologic neglect syndrome | 180 | 68.7 57.5–82.0ROR 68.7 · calibrated p 2e-6 ✓ | 46.4 EB05 41.0 · IC025 +5.1 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=180 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Total lung capacity abnormal | 104 | 54.4 43.4–68.2ROR 54.4 · calibrated p 1e-5 ✓ | 39.4 EB05 33.4 · IC025 +4.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=104 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Pulmonary vasculitis | 131 | 47.7 39.1–58.1ROR 47.7 · calibrated p 2e-5 ✓ | 35.8 EB05 30.9 · IC025 +4.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Labeled (related wording) related wording | serious n=131 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Amaurosis fugax | 242 | 42.3 36.7–48.8ROR 42.4 · calibrated p 4e-5 ✓ | 32.8 EB05 29.4 · IC025 +4.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=242 · 100% clinician | not reported in cached trials |
| Carotid artery thrombosis | 183 | 39.5 33.5–46.5ROR 39.5 · calibrated p 6e-5 ✓ | 31.0 EB05 27.4 · IC025 +4.6 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=183 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Atrial tachycardia | 436 | 37.7 33.9–41.9ROR 37.8 · calibrated p 8e-5 ✓ | 30.0 EB05 27.7 · IC025 +4.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=434 | not reported in cached trials |
| Milk-alkali syndrome | 102 | 34.6 27.9–43.0ROR 34.7 · calibrated p 1e-4 ✓ | 27.9 EB05 23.7 · IC025 +4.3 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=102 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Pruritus genital | 407 | 30.6 27.5–34.1ROR 30.7 · calibrated p 2e-4 ✓ | 25.3 EB05 23.3 · IC025 +4.5 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=396 | not reported in cached trials |
| Adjustment disorder | 183 | 23.6 20.2–27.6ROR 23.6 · calibrated p 1e-3 ✓ | 20.3 EB05 18.0 · IC025 +4.0 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=182 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Carotid artery occlusion | 480 | 21.8 19.8–24.0ROR 21.9 · calibrated p 0.001 ✓ | 19.0 EB05 17.6 · IC025 +4.1 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=479 | not reported in cached trials |
| Female genital tract fistula | 207 | 19.7 17.1–22.8ROR 19.8 · calibrated p 0.002 ✓ | 17.4 EB05 15.5 · IC025 +3.8 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=207 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 124 | 18.8 15.6–22.7ROR 18.8 · calibrated p 0.003 ✓ | 16.7 EB05 14.4 · IC025 +3.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=124 | not reported in cached trials |
| Nephrogenic anaemia | 531 | 18.5 16.9–20.3ROR 18.6 · calibrated p 0.003 ✓ | 16.5 EB05 15.3 · IC025 +3.9 3/3 methods agree vs other Thiazide Diuretics: only this drug | Likely indication confounding shares a disease stem with the indications wording | serious n=531 | not reported in cached trials |
| Dust allergy | 103 | 17.3 14.1–21.2ROR 17.3 · calibrated p 0.004 ✓ | 15.4 EB05 13.1 · IC025 +3.5 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=103 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Hyperparathyroidism secondary | 270 | 17.2 15.2–19.6ROR 17.3 · calibrated p 0.004 ✓ | 15.5 EB05 14.0 · IC025 +3.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=269 | not reported in cached trials |
| Tension headache | 434 | 16.2 14.7–17.9ROR 16.3 · calibrated p 0.005 ✓ | 14.6 EB05 13.5 · IC025 +3.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Labeled (related wording) related wording | serious n=414 | not reported in cached trials |
| Radiculopathy | 261 | 15.9 14.0–18.0ROR 15.9 · calibrated p 0.006 ✓ | 14.3 EB05 12.9 · IC025 +3.6 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=258 · ♀ 100% (drug 64%) | not reported in cached trials |
| Neuritis | 152 | 15.8 13.4–18.7ROR 15.8 · calibrated p 0.006 ✓ | 14.3 EB05 12.5 · IC025 +3.5 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=149 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Sleep terror | 404 | 15.3 13.8–17.0ROR 15.4 · calibrated p 0.006 ✓ | 13.9 EB05 12.8 · IC025 +3.6 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=399 | not reported in cached trials |
| Chronic sinusitis | 348 | 14.8 13.2–16.5ROR 14.8 · calibrated p 0.007 ✓ | 13.5 EB05 12.3 · IC025 +3.6 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=338 · ♀ 100% (drug 64%) | not reported in cached trials |
| Rebound acid hypersecretion | 263 | 13.5 11.9–15.4ROR 13.6 · calibrated p 0.011 ✓ | 12.4 EB05 11.2 · IC025 +3.4 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=263 | not reported in cached trials |
| Blood pressure systolic abnormal | 202 | 12.7 11.0–14.7ROR 12.8 · calibrated p 0.014 ✓ | 11.7 EB05 10.4 · IC025 +3.3 3/3 methods agree vs other Thiazide Diuretics: only this drug | Lab value / disease marker | serious n=200 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Macular degeneration | 895 | 11.7 10.9–12.5ROR 11.8 · calibrated p 0.018 ✓ | 10.9 EB05 10.3 · IC025 +3.3 3/3 methods agree vs other Thiazide Diuretics: PRR 479.1 (179.4–1,279.2) | Not in label — unassessed | serious PRR 10.0 · ♀ 94% (drug 64%) | not reported in cached trials |
| Proctitis | 210 | 11.7 10.1–13.4ROR 11.7 · calibrated p 0.019 ✓ | 10.8 EB05 9.6 · IC025 +3.2 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=209 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Personality disorder | 195 | 11.5 10.0–13.3ROR 11.5 · calibrated p 0.020 ✓ | 10.7 EB05 9.4 · IC025 +3.2 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=193 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Conjunctivitis allergic | 104 | 11.0 9.0–13.5ROR 11.1 · calibrated p 0.024 ✓ | 10.1 EB05 8.6 · IC025 +3.0 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=103 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Blood pressure diastolic abnormal | 173 | 10.4 8.9–12.2ROR 10.4 · calibrated p 0.029 ✓ | 9.7 EB05 8.5 · IC025 +3.0 3/3 methods agree vs other Thiazide Diuretics: only this drug | Lab value / disease marker | serious n=171 · ♀ 100% (drug 64%) · 100% clinician | not reported in cached trials |
| Eosinophilic granulomatosis with polyangiitis | 133 | 10.2 8.5–12.1ROR 10.2 · calibrated p 0.031 ✓ | 9.4 EB05 8.1 · IC025 +2.9 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=133 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Facial pain | 545 | 9.4 8.6–10.2ROR 9.4 · calibrated p 0.040 ✓ | 8.8 EB05 8.2 · IC025 +3.0 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=515 | not reported in cached trials |
| Blood pressure diastolic decreased | 415 | 8.6 7.7–9.4ROR 8.6 · calibrated p 0.054 | 8.1 EB05 7.4 · IC025 +2.8 3/3 methods agree vs other Thiazide Diuretics: only this drug | Lab value / disease marker | serious PRR 7.3 | not reported in cached trials |
| Urinary tract disorder | 250 | 8.5 7.5–9.6ROR 8.5 · calibrated p 0.056 | 8.0 EB05 7.2 · IC025 +2.8 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious n=239 · 100% clinician | not reported in cached trials |
| Haemorrhagic stroke | 433 | 8.4 7.6–9.3ROR 8.4 · calibrated p 0.057 | 7.9 EB05 7.3 · IC025 +2.8 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | serious PRR 6.9 | not reported in cached trials |
| Vasculitis | 630 | 8.2 7.6–8.9ROR 8.3 · calibrated p 0.060 | 7.8 EB05 7.3 · IC025 +2.8 3/3 methods agree vs other Thiazide Diuretics: only this drug | Labeled adverse reaction exact term | age-adj. PRR 8.1 · serious PRR 7.1 | not reported in cached trials |
| Forced expiratory volume decreased | 152 | 8.2 6.9–9.6ROR 8.2 · calibrated p 0.064 | 7.6 EB05 6.7 · IC025 +2.7 3/3 methods agree vs other Thiazide Diuretics: only this drug | Lab value / disease marker | serious n=150 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Respiratory symptom | 149 | 8.1 6.9–9.6ROR 8.1 · calibrated p 0.065 | 7.6 EB05 6.6 · IC025 +2.6 3/3 methods agree vs other Thiazide Diuretics: only this drug | Labeled (related wording) related wording | serious n=144 · ♀ 0% (drug 64%) · 100% clinician | not reported in cached trials |
| Hyponatraemia (low sodium) | 2,897 | 7.8 7.6–8.1ROR 8.0 · calibrated p 0.067 | 7.5 EB05 7.3 · IC025 +2.8 3/3 methods agree vs other Thiazide Diuretics: PRR 163.2 (118.6–224.7) | Not in label — unassessed | age-adj. PRR 6.1 · serious PRR 6.4 | NCT02185417: 362/6,767 (5.3%) on Hydrochlorothiazide |
Clinical concept groups
MedDRA splits one clinical problem across several terms (e.g. "neutropenia", "neutrophil count decreased", "agranulocytosis"), which dilutes term-level signals. These rows count reports with any term in a concept group (an exact union, not a sum), compared with all other drugs. Groups are hand-built and listed in the methods.
| Concept | Reports | PRR 95% CI | Reading |
|---|---|---|---|
| Hyponatraemia | 3,589 | 6.76.5–7.0 | signal |
| Kidney injury | 10,290 | 3.33.3–3.4 | signal |
| Arrhythmia / qt | 3,444 | 2.62.5–2.7 | signal |
| Pancreatitis | 1,363 | 2.52.4–2.6 | signal |
| Fall / fracture | 6,072 | 2.32.3–2.4 | signal |
| Gi bleeding | 2,762 | 2.22.1–2.3 | signal |
| Hyperglycaemia / diabetes | 5,176 | 2.22.1–2.3 | signal |
| Rhabdomyolysis / myopathy | 1,176 | 2.12.0–2.2 | signal |
| Myocardial infarction | 2,922 | 2.12.0–2.2 | signal |
| Hypoglycaemia | 1,345 | 2.11.9–2.2 | raised |
| Tendon disorder | 526 | 2.01.9–2.2 | raised |
| Stroke | 3,404 | 2.01.9–2.1 | raised |
| Anaemia | 3,877 | 1.91.8–1.9 | raised |
| Heart failure | 2,297 | 1.91.8–2.0 | raised |
| Anaphylaxis / angioedema | 1,528 | 1.81.7–1.9 | raised |
| Depression | 3,327 | 1.71.7–1.8 | raised |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Hydrochlorothiazide as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (1 of 40 signal terms matched).
- NCT02185417 — Diuretic Comparison Project (N=20723, PHASE3; 9 AE terms posted; arms: Hydrochlorothiazide; Chlorthalidone)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
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 |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 10,330 | 1.9 1.9–2.0ROR 2.0 · calibrated p 0.953 | 1.9 EB05 1.9 · IC025 +0.9 vs other Thiazide Diuretics: only this drug | Not in label — unassessed | age-adj. PRR 1.7 · serious PRR 2.1 | not reported in cached trials |
| Nausea | 9,966 | 1.8 1.8–1.9ROR 1.9 · calibrated p 0.893 | 1.8 EB05 1.8 · IC025 +0.8 vs other Thiazide Diuretics: PRR 52.8 (47.9–58.3) | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 2.1 | not reported in cached trials |
| Drug ineffective (drug did not work) | 9,606 | 1.1 1.0–1.1ROR 1.1 · calibrated p 0.349 | 1.1 EB05 1.0 · IC025 +0.0 vs other Thiazide Diuretics: only this drug | Reporting / coding artifact | age-adj. PRR 1.2 · serious PRR 1.5 | not reported in cached trials |
| Diarrhoea (diarrhea) | 8,590 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.951 | 1.9 EB05 1.9 · IC025 +0.9 vs other Thiazide Diuretics: PRR 31.5 (29.1–34.3) | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 2.0 | not reported in cached trials |
| Pain | 7,864 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.898 | 1.9 EB05 1.8 · IC025 +0.9 vs other Thiazide Diuretics: only this drug | Labeled adverse reaction exact term | age-adj. PRR 2.1 · serious PRR 1.9 | not reported in cached trials |
| Headache | 7,780 | 1.8 1.8–1.9ROR 1.9 · calibrated p 0.866 | 1.8 EB05 1.8 · IC025 +0.8 vs other Thiazide Diuretics: only this drug | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 2.1 | not reported in cached trials |
| Dyspnoea (shortness of breath) | 7,774 | 2.0 2.0–2.1ROR 2.1 · calibrated p 0.980 | 2.0 EB05 2.0 · IC025 +1.0 vs other Thiazide Diuretics: only this drug | Not in label — unassessed | age-adj. PRR 1.7 · serious PRR 1.9 | not reported in cached trials |
| Dizziness | 7,496 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.917 | 2.2 EB05 2.1 · IC025 +1.1 3/3 methods agree vs other Thiazide Diuretics: PRR 27.0 (24.9–29.3) | Labeled adverse reaction exact term | age-adj. PRR 1.9 · serious PRR 2.3 | not reported in cached trials |
| Arthralgia (joint pain) | 6,273 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.916 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | age-adj. PRR 1.9 · serious PRR 2.6 | not reported in cached trials |
| Off label use (used outside approved label) | 5,935 | 1.0 1.0–1.0ROR 1.0 · calibrated p 0.302 | 1.0 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC vs other Thiazide Diuretics: only this drug | Reporting / coding artifact | age-adj. PRR 1.0 · serious PRR 1.1 | not reported in cached trials |
| Asthenia (weakness) | 5,742 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.909 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | age-adj. PRR 1.8 · serious PRR 2.2 | not reported in cached trials |
| Fall | 5,705 | 2.5 2.5–2.6ROR 2.6 · calibrated p 0.779 | 2.5 EB05 2.4 · IC025 +1.3 3/3 methods agree vs other Thiazide Diuretics: only this drug | Not in label — unassessed | age-adj. PRR 1.9 · serious PRR 2.3 | not reported in cached trials |
| Vomiting | 5,702 | 1.8 1.7–1.8ROR 1.8 · calibrated p 0.834 | 1.8 EB05 1.7 · IC025 +0.8 vs other Thiazide Diuretics: only this drug | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 1.8 | not reported in cached trials |
| Malaise (feeling unwell) | 5,345 | 1.8 1.7–1.8ROR 1.8 · calibrated p 0.833 | 1.8 EB05 1.7 · IC025 +0.8 vs other Thiazide Diuretics: only this drug | Not in label — unassessed | age-adj. PRR 1.7 · serious PRR 2.0 | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 5,029 | 4.9 4.8–5.1ROR 5.1 · calibrated p 0.227 | 4.8 EB05 4.7 · IC025 +2.2 3/3 methods agree vs other Thiazide Diuretics: PRR 10.9 (10.2–11.7) | Labeled (related wording) related wording | age-adj. PRR 3.4 · serious PRR 4.1 | NCT02185417: 512/6,767 (7.6%) on Hydrochlorothiazide |
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.
- Vaginal flatulence — n=188, PRR 234.7
- Immunisation — n=257, PRR 213.9
- Palmoplantar keratoderma — n=386, PRR 169.0
- Neurologic neglect syndrome — n=180, PRR 68.7
- Total lung capacity abnormal — n=104, PRR 54.4
- Amaurosis fugax — n=242, PRR 42.3
- Carotid artery thrombosis — n=183, PRR 39.5
- Atrial tachycardia — n=436, PRR 37.7
- Milk-alkali syndrome — n=102, PRR 34.6
- Pruritus genital — n=407, PRR 30.6
✓ A hand-written Bradford Hill causality assessment exists for this drug: Hydrochlorothiazide (thiazides) ↔ Hyponatraemia.
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 Hydrochlorothiazide?
In FDA FAERS, the most frequently co-reported reaction terms for Hydrochlorothiazide are fatigue, nausea, diarrhoea, pain, headache, dyspnoea. 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 Hydrochlorothiazide have an FDA boxed warning?
No. The FDA label retrieved for Hydrochlorothiazide has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Hydrochlorothiazide 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 01ad3531-5ed9-434c-b7d5-02d72aa82e46, effective 20231225; matched on
openfda.generic_name.exact:"HYDROCHLOROTHIAZIDE" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG") - PubChem CID 3639 description (ChEBI)
- 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, 1,166 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 - ClinicalTrials.gov API v2 (query
HYDROCHLOROTHIAZIDE, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. 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.