Drug · FAERS side-effect profile with label screen
Terazosin Hydrochloride side effects: what 8,841 FDA adverse event reports show
Drug class
Not stated in label
Who reports
8,841 reports · 69% serious · 951 with death outcome · 15% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Terazosin capsules are indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH). There is a rapid response, with approximately 70% of patients experiencing an increase in urinary flow and improvement in symptoms of BPH when treated with terazosin capsules.
FDA label, Indications and Usage
What it is
DESCRIPTION Terazosin hydrochloride, USP an alpha-1-selective adrenoceptor blocking agent, is a quinazoline derivative represented by the following chemical name and structural formula: (RS)-Piperazine,1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-[(tetra-hydro-2-furanyl)carbonyl]-, monohydrochloride, dihydrate.
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 7Lab 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.
- 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. 1,016 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 |
|---|---|---|---|---|---|---|
| Myasthenic syndrome | 20 | 63.9 41.0–99.6ROR 64.1 · χ² 1,145 / p 2e-251 | 58.9 EB05 40.3 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=20 | no trial data cached |
| Chronic kidney disease-mineral and bone disorder | 24 | 54.1 36.1–81.0ROR 54.2 · χ² 1,171 / p 6e-257 | 50.9 EB05 36.0 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=24 | no trial data cached |
| White coat hypertension | 10 | 44.6 23.9–83.4ROR 44.7 · χ² 377 / p 3e-84 | 40.7 EB05 23.6 · IC025 +2.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=10 | no trial data cached |
| Hyperparathyroidism secondary | 41 | 39.0 28.7–53.1ROR 39.2 · χ² 1,457 / p <1e-300 | 37.8 EB05 29.0 · IC025 +4.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=41 | no trial data cached |
| Nephrogenic anaemia | 74 | 38.1 30.3–47.9ROR 38.4 · χ² 2,597 / p <1e-300 | 37.2 EB05 30.6 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=74 | no trial data cached |
| Neoplasm skin | 23 | 35.6 23.6–53.7ROR 35.7 · χ² 728 / p 1e-160 | 34.2 EB05 24.0 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=23 · ♀ 100% (drug 15%) | no trial data cached |
| Micturition frequency decreased | 10 | 31.9 17.1–59.5ROR 31.9 · χ² 265 / p 6e-60 | 29.8 EB05 17.2 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Diffuse alveolar damage | 11 | 22.8 12.6–41.3ROR 22.8 · χ² 206 / p 5e-47 | 21.6 EB05 12.4 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Prostatomegaly | 32 | 19.5 13.8–27.6ROR 19.5 · χ² 538 / p 2e-119 | 19.1 EB05 14.1 · IC025 +3.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=28 | no trial data cached |
| Bradyarrhythmia | 13 | 18.9 11.0–32.6ROR 19.0 · χ² 202 / p 5e-46 | 18.0 EB05 10.6 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| End stage renal disease | 139 | 18.0 15.3–21.3ROR 18.3 · χ² 2,203 / p <1e-300 | 17.9 EB05 15.5 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 14.9 | no trial data cached |
| Rebound acid hypersecretion | 23 | 17.9 11.9–27.0ROR 18.0 · χ² 348 / p 6e-78 | 17.4 EB05 12.0 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=23 | no trial data cached |
| Transplant dysfunction | 13 | 17.6 10.2–30.4ROR 17.7 · χ² 186 / p 1e-42 | 16.6 EB05 9.6 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Blood pressure diastolic abnormal | 17 | 15.8 9.8–25.4ROR 15.8 · χ² 219 / p 6e-50 | 15.0 EB05 9.4 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious n=17 | no trial data cached |
| Aortic arteriosclerosis | 17 | 15.7 9.8–25.3ROR 15.7 · χ² 218 / p 1e-49 | 15.0 EB05 9.4 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| Benign prostatic hyperplasia | 32 | 14.7 10.4–20.8ROR 14.8 · χ² 394 / p 7e-88 | 14.3 EB05 10.4 · IC025 +3.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=29 | no trial data cached |
| Distributive shock | 13 | 14.0 8.1–24.2ROR 14.0 · χ² 144 / p 2e-33 | 12.7 EB05 7.1 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Vulvovaginal mycotic infection | 23 | 14.0 9.3–21.0ROR 14.0 · χ² 263 / p 2e-59 | 13.4 EB05 9.0 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=23 · ♀ 100% (drug 15%) | no trial data cached |
| Heart valve incompetence | 16 | 13.3 8.1–21.7ROR 13.3 · χ² 168 / p 8e-39 | 12.2 EB05 7.3 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Pulseless electrical activity | 23 | 13.1 8.7–19.8ROR 13.2 · χ² 245 / p 2e-55 | 12.5 EB05 8.3 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=23 · 100% clinician | no trial data cached |
| Potentiating drug interaction | 18 | 13.1 8.2–20.8ROR 13.1 · χ² 188 / p 5e-43 | 12.1 EB05 7.6 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Hypertonic bladder | 15 | 12.4 7.5–20.6ROR 12.4 · χ² 145 / p 8e-34 | 11.1 EB05 6.6 · IC025 +2.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=13 | no trial data cached |
| Haemorrhagic anaemia | 23 | 12.3 8.2–18.5ROR 12.3 · χ² 226 / p 2e-51 | 11.5 EB05 7.7 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=23 | no trial data cached |
| Haemorrhoidal haemorrhage | 24 | 11.6 7.8–17.3ROR 11.7 · χ² 221 / p 2e-50 | 10.8 EB05 7.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=23 · ♀ 100% (drug 15%) | no trial data cached |
| Chronic kidney disease | 333 | 10.3 9.3–11.5ROR 10.7 · χ² 2,799 / p <1e-300 | 10.3 EB05 9.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.6 | no trial data cached |
| Hypovolaemia | 25 | 10.2 6.9–15.1ROR 10.2 · χ² 197 / p 5e-45 | 9.3 EB05 6.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=24 · ♀ 76% (drug 15%) | no trial data cached |
| Blood pressure systolic abnormal | 10 | 9.6 5.1–17.8ROR 9.6 · χ² 68 / p 8e-17 | 7.5 EB05 4.1 · IC025 +1.7 3/3 methods agree | Lab value / disease marker | serious n=10 | no trial data cached |
| Prostatic disorder | 22 | 9.5 6.2–14.4ROR 9.5 · χ² 158 / p 2e-36 | 8.5 EB05 5.7 · IC025 +2.3 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=22 | no trial data cached |
| Peripheral vascular disorder | 20 | 9.2 5.9–14.2ROR 9.2 · χ² 137 / p 6e-32 | 8.1 EB05 5.3 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious n=19 | no trial data cached |
| Snoring | 14 | 8.8 5.2–14.9ROR 8.8 · χ² 89 / p 2e-21 | 7.4 EB05 4.5 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Orthostatic hypotension (dizziness on standing) | 62 | 8.5 6.6–10.8ROR 8.5 · χ² 399 / p 5e-89 | 8.1 EB05 6.5 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.7 · 90% clinician | no trial data cached |
| Ischaemic cardiomyopathy | 11 | 8.4 4.7–15.3ROR 8.5 · χ² 65 / p 4e-16 | 6.7 EB05 3.8 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Aortic stenosis | 12 | 8.2 4.7–14.4ROR 8.2 · χ² 69 / p 6e-17 | 6.6 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Lower gastrointestinal haemorrhage | 25 | 8.0 5.4–11.9ROR 8.0 · χ² 146 / p 6e-34 | 7.2 EB05 5.0 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 | no trial data cached |
| Prostatitis | 10 | 7.8 4.2–14.6ROR 7.8 · χ² 53 / p 2e-13 | 6.1 EB05 3.4 · IC025 +1.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=10 | no trial data cached |
| Diverticulum | 23 | 7.6 5.0–11.4ROR 7.6 · χ² 125 / p 3e-29 | 6.8 EB05 4.7 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=23 | no trial data cached |
| Upper gastrointestinal haemorrhage | 53 | 7.5 5.7–9.8ROR 7.5 · χ² 290 / p 3e-65 | 7.1 EB05 5.6 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Tongue oedema | 12 | 7.5 4.2–13.1ROR 7.5 · χ² 61 / p 4e-15 | 6.0 EB05 3.6 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Hepatic neoplasm | 10 | 7.3 3.9–13.6ROR 7.3 · χ² 48 / p 2e-12 | 5.7 EB05 3.3 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Blood pressure systolic increased | 60 | 7.3 5.7–9.4ROR 7.3 · χ² 318 / p 2e-71 | 6.9 EB05 5.6 · IC025 +2.4 3/3 methods agree | Lab value / disease marker | serious PRR 6.3 · ♀ 36% (drug 15%) | 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 ineffective (drug did not work) | 549 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.402 | 1.0 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.1 | no trial data cached |
| Fatigue (tiredness) | 543 | 1.7 1.5–1.8ROR 1.7 · χ² 147 / p 5e-34 | 1.7 EB05 1.5 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.6 | no trial data cached |
| Dyspnoea (shortness of breath) | 500 | 2.1 1.9–2.3ROR 2.2 · χ² 294 / p 4e-66 | 2.1 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 1.9 | no trial data cached |
| Diarrhoea (diarrhea) | 457 | 1.7 1.5–1.8ROR 1.7 · χ² 131 / p 1e-30 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.4 | no trial data cached |
| Dizziness | 455 | 2.2 2.0–2.4ROR 2.2 · χ² 292 / p 9e-66 | 2.2 EB05 2.0 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.2 | no trial data cached |
| Asthenia (weakness) | 416 | 2.6 2.4–2.9ROR 2.7 · χ² 424 / p 2e-94 | 2.6 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.3 | no trial data cached |
| Death | 387 | 1.1 1.0–1.2ROR 1.1 · χ² 2 / p 0.105 | 1.1 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction | serious PRR 0.9 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 375 | 5.9 5.3–6.5ROR 6.1 · χ² 1,511 / p <1e-300 | 5.8 EB05 5.3 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Off label use (used outside approved label) | 365 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.491 | 1.0 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.1 | no trial data cached |
| Fall | 347 | 2.5 2.2–2.7ROR 2.5 · χ² 309 / p 2e-69 | 2.5 EB05 2.3 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.2 | no trial data cached |
| Nausea | 346 | 1.0 0.9–1.2ROR 1.0 · χ² 1 / p 0.237 | 1.0 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 1.1 | no trial data cached |
| Chronic kidney disease | 333 | 10.3 9.3–11.5ROR 10.7 · χ² 2,799 / p <1e-300 | 10.3 EB05 9.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.6 | no trial data cached |
| Renal failure (kidney failure) | 330 | 5.9 5.3–6.5ROR 6.1 · χ² 1,331 / p 1e-291 | 5.8 EB05 5.3 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Pain | 328 | 1.3 1.1–1.4ROR 1.3 · χ² 18 / p 9e-6 | 1.3 EB05 1.2 · IC025 +0.2 | Labeled adverse reaction exact term | serious PRR 1.2 | no trial data cached |
| Pneumonia (lung infection) | 321 | 2.4 2.1–2.6ROR 2.4 · χ² 253 / p 3e-57 | 2.4 EB05 2.1 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.0 | 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.
- Myasthenic syndrome — n=20, PRR 63.9
- Chronic kidney disease-mineral and bone disorder — n=24, PRR 54.1
- Nephrogenic anaemia — n=74, PRR 38.1
- Neoplasm skin — n=23, PRR 35.6
- End stage renal disease — n=139, PRR 18.0
- Rebound acid hypersecretion — n=23, PRR 17.9
- Vulvovaginal mycotic infection — n=23, PRR 14.0
- Pulseless electrical activity — n=23, PRR 13.1
- Haemorrhagic anaemia — n=23, PRR 12.3
- Haemorrhoidal haemorrhage — n=24, PRR 11.6
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 Terazosin?
In FDA FAERS, the most frequently co-reported reaction terms for Terazosin are fatigue, dyspnoea, diarrhoea, dizziness, asthenia, acute kidney injury. 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 Terazosin have an FDA boxed warning?
No. The FDA label retrieved for Terazosin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Terazosin 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 130c84dc-b598-660f-e063-6294a90a8e46, effective 20241220; matched on
openfda.generic_name.exact:"TERAZOSIN") - 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, 1,056 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.