Drug · FAERS side-effect profile with label screen
Terazosin side effects: what 7,570 FDA adverse event reports show
Drug class
Not stated in label
Who reports
7,570 reports · 69% serious · 848 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 2Labeled (related wording) 2Reporting / coding artifact 2Lab value / disease marker 5Not in label — unassessed 29
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.
- 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. 570 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 |
|---|---|---|---|---|---|---|
| End stage renal disease | 135 | 20.4 17.3–24.2ROR 20.8 · χ² 2,461 / p <1e-300 | 20.3 EB05 17.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 17.0 | no trial data cached |
| Chronic kidney disease | 320 | 11.6 10.4–12.9ROR 12.1 · χ² 3,090 / p <1e-300 | 11.5 EB05 10.5 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | no trial data cached |
| Upper gastrointestinal haemorrhage | 50 | 8.2 6.2–10.9ROR 8.3 · χ² 310 / p 1e-69 | 7.8 EB05 6.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Renal injury | 83 | 7.7 6.2–9.5ROR 7.8 · χ² 475 / p 2e-105 | 7.4 EB05 6.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Sleep apnoea syndrome | 51 | 7.4 5.6–9.7ROR 7.4 · χ² 276 / p 3e-62 | 7.0 EB05 5.5 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Orthostatic hypotension (dizziness on standing) | 46 | 7.3 5.5–9.8ROR 7.4 · χ² 244 / p 2e-55 | 6.9 EB05 5.3 · IC025 +2.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.1 | no trial data cached |
| Nocturia (night-time urination) | 30 | 6.9 4.8–9.8ROR 6.9 · χ² 145 / p 1e-33 | 6.3 EB05 4.6 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · 78% consumer | no trial data cached |
| Blood pressure systolic increased | 47 | 6.7 5.0–8.9ROR 6.7 · χ² 220 / p 4e-50 | 6.3 EB05 4.9 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 5.8 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 351 | 6.4 5.8–7.1ROR 6.7 · χ² 1,600 / p <1e-300 | 6.3 EB05 5.8 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Renal failure (kidney failure) | 303 | 6.3 5.6–7.0ROR 6.5 · χ² 1,347 / p 3e-295 | 6.2 EB05 5.7 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Intervertebral disc degeneration | 21 | 6.3 4.1–9.6ROR 6.3 · χ² 87 / p 4e-21 | 5.6 EB05 3.8 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 | no trial data cached |
| Hyperkalaemia (high potassium) | 77 | 6.1 4.9–7.6ROR 6.2 · χ² 325 / p 7e-73 | 5.9 EB05 4.9 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 · 92% clinician | no trial data cached |
| Sinus bradycardia | 21 | 6.0 3.9–9.2ROR 6.0 · χ² 83 / p 5e-20 | 5.4 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Prostatic specific antigen increased | 29 | 5.8 4.0–8.4ROR 5.8 · χ² 111 / p 4e-26 | 5.3 EB05 3.9 · IC025 +1.8 3/3 methods agree | Lab value / disease marker | serious PRR 2.8 · 79% consumer | no trial data cached |
| Blood glucose fluctuation | 23 | 5.8 3.9–8.7ROR 5.8 · χ² 87 / p 7e-21 | 5.2 EB05 3.7 · IC025 +1.7 3/3 methods agree | Lab value / disease marker | serious n=17 | no trial data cached |
| Tubulointerstitial nephritis | 39 | 5.8 4.2–7.9ROR 5.8 · χ² 149 / p 1e-34 | 5.4 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Gout | 37 | 5.7 4.1–7.9ROR 5.7 · χ² 139 / p 2e-32 | 5.3 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.3 | no trial data cached |
| Gastrointestinal haemorrhage | 168 | 5.5 4.8–6.4ROR 5.6 · χ² 622 / p 1e-137 | 5.5 EB05 4.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Blood pressure fluctuation | 47 | 5.4 4.1–7.2ROR 5.4 · χ² 165 / p 5e-38 | 5.1 EB05 4.0 · IC025 +1.9 3/3 methods agree | Lab value / disease marker | serious PRR 5.1 · ♀ 41% (drug 15%) | no trial data cached |
| Splenomegaly | 22 | 5.2 3.4–7.9ROR 5.2 · χ² 71 / p 2e-17 | 4.7 EB05 3.3 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Dizziness postural | 18 | 5.2 3.3–8.3ROR 5.2 · χ² 57 / p 2e-14 | 4.6 EB05 3.1 · IC025 +1.4 3/3 methods agree | Labeled (related wording) related wording | serious n=10 | no trial data cached |
| Atelectasis | 18 | 5.1 3.2–8.2ROR 5.2 · χ² 56 / p 4e-14 | 4.6 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 | no trial data cached |
| Iron deficiency anaemia | 17 | 5.1 3.2–8.3ROR 5.1 · χ² 52 / p 2e-13 | 4.5 EB05 3.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Renal tubular necrosis | 18 | 5.1 3.2–8.1ROR 5.1 · χ² 55 / p 6e-14 | 4.5 EB05 3.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | no trial data cached |
| Obesity | 29 | 5.0 3.5–7.3ROR 5.1 · χ² 90 / p 1e-21 | 4.7 EB05 3.4 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Glomerular filtration rate decreased | 22 | 5.0 3.3–7.6ROR 5.0 · χ² 67 / p 1e-16 | 4.6 EB05 3.2 · IC025 +1.5 3/3 methods agree | Lab value / disease marker | serious PRR 5.0 | no trial data cached |
| Rotator cuff syndrome | 23 | 4.9 3.3–7.4ROR 5.0 · χ² 68 / p 6e-17 | 4.5 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 | no trial data cached |
| Pulmonary mass | 26 | 4.8 3.3–7.1ROR 4.9 · χ² 76 / p 2e-18 | 4.5 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Hyperbilirubinaemia | 18 | 4.8 3.1–7.7ROR 4.9 · χ² 51 / p 4e-13 | 4.3 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Dysuria (painful urination) | 64 | 4.8 3.8–6.1ROR 4.8 · χ² 190 / p 2e-43 | 4.7 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Lactic acidosis | 55 | 4.8 3.7–6.2ROR 4.8 · χ² 159 / p 8e-37 | 4.6 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 · 95% clinician | no trial data cached |
| Anhedonia | 45 | 4.7 3.5–6.3ROR 4.7 · χ² 128 / p 6e-30 | 4.5 EB05 3.5 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 | no trial data cached |
| Economic problem | 26 | 4.7 3.2–6.9ROR 4.7 · χ² 72 / p 1e-17 | 4.3 EB05 3.1 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 4.0 | no trial data cached |
| Back disorder | 27 | 4.6 3.1–6.7ROR 4.6 · χ² 72 / p 1e-17 | 4.3 EB05 3.1 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.3 · ♀ 40% (drug 15%) | no trial data cached |
| Presyncope (near-fainting) | 40 | 4.6 3.4–6.2ROR 4.6 · χ² 108 / p 1e-25 | 4.4 EB05 3.3 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Basal cell carcinoma | 25 | 4.4 3.0–6.6ROR 4.5 · χ² 63 / p 9e-16 | 4.1 EB05 2.9 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | no trial data cached |
| Squamous cell carcinoma | 15 | 4.4 2.7–7.3ROR 4.4 · χ² 36 / p 9e-10 | 3.9 EB05 2.5 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Hypothermia | 16 | 4.4 2.7–7.1ROR 4.4 · χ² 38 / p 3e-10 | 3.9 EB05 2.6 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | no trial data cached |
| Drug level decreased | 16 | 4.3 2.7–7.1ROR 4.3 · χ² 38 / p 4e-10 | 3.9 EB05 2.6 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 3.9 | no trial data cached |
| Osteopenia | 23 | 4.2 2.8–6.3ROR 4.2 · χ² 52 / p 2e-13 | 3.9 EB05 2.7 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | 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 |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 474 | 1.7 1.5–1.8ROR 1.7 · χ² 138 / p 4e-32 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.6 | no trial data cached |
| Diarrhoea (diarrhea) | 399 | 1.7 1.6–1.9ROR 1.8 · χ² 123 / p 7e-29 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.4 | no trial data cached |
| Dizziness | 392 | 2.2 2.0–2.4ROR 2.2 · χ² 256 / p 7e-58 | 2.2 EB05 2.0 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.1 | no trial data cached |
| Dyspnoea (shortness of breath) | 391 | 1.9 1.7–2.1ROR 2.0 · χ² 175 / p 3e-40 | 1.9 EB05 1.8 · IC025 +0.8 | Labeled adverse reaction exact term | serious PRR 1.7 | no trial data cached |
| Asthenia (weakness) | 361 | 2.7 2.4–2.9ROR 2.7 · χ² 379 / p 1e-84 | 2.7 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.4 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 351 | 6.4 5.8–7.1ROR 6.7 · χ² 1,600 / p <1e-300 | 6.3 EB05 5.8 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Death | 336 | 1.1 1.0–1.2ROR 1.1 · χ² 2 / p 0.077 | 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 |
| Chronic kidney disease | 320 | 11.6 10.4–12.9ROR 12.1 · χ² 3,090 / p <1e-300 | 11.5 EB05 10.5 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | no trial data cached |
| Renal failure (kidney failure) | 303 | 6.3 5.6–7.0ROR 6.5 · χ² 1,347 / p 3e-295 | 6.2 EB05 5.7 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Fall | 288 | 2.4 2.1–2.7ROR 2.5 · χ² 238 / p 7e-54 | 2.4 EB05 2.2 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.2 | no trial data cached |
| Pain | 272 | 1.2 1.1–1.4ROR 1.2 · χ² 11 / p 4e-4 | 1.2 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 1.2 | no trial data cached |
| Pneumonia (lung infection) | 259 | 2.2 2.0–2.5ROR 2.3 · χ² 175 / p 3e-40 | 2.2 EB05 2.0 · IC025 +0.9 | Labeled (related wording) related wording | serious PRR 1.9 | no trial data cached |
| Hypotension (low blood pressure) | 254 | 3.5 3.1–4.0ROR 3.6 · χ² 459 / p 5e-102 | 3.5 EB05 3.1 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | no trial data cached |
| Weight decreased (weight loss) | 212 | 2.1 1.8–2.4ROR 2.1 · χ² 123 / p 5e-29 | 2.1 EB05 1.9 · IC025 +0.8 | Labeled (related wording) related wording | serious PRR 1.9 | no trial data cached |
| Malaise (feeling unwell) | 202 | 1.3 1.1–1.5ROR 1.3 · χ² 12 / p 3e-4 | 1.3 EB05 1.1 · IC025 +0.1 | Not in label — unassessed | serious PRR 1.4 | 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.
- End stage renal disease — n=135, PRR 20.4
- Chronic kidney disease — n=320, PRR 11.6
- Upper gastrointestinal haemorrhage — n=50, PRR 8.2
- Renal injury — n=83, PRR 7.7
- Sleep apnoea syndrome — n=51, PRR 7.4
- Nocturia — n=30, PRR 6.9
- Acute kidney injury — n=351, PRR 6.4
- Renal failure — n=303, PRR 6.3
- Intervertebral disc degeneration — n=21, PRR 6.3
- Hyperkalaemia — n=77, PRR 6.1
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 Terazosin?
In FDA FAERS, the most frequently co-reported reaction terms for Terazosin are fatigue, diarrhoea, dizziness, dyspnoea, 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, 610 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.