Doxazosin Mesylate side effects: what 35,889 FDA adverse event reports show
Drug class
Not stated in label
Who reports
35,889 reports · 83% serious · 3,117 with death outcome · 34% female
Used for
Doxazosin tablets are an alpha 1 adrenergic antagonist indicated for: • Signs and symptoms of Benign Prostatic Hyperplasia (BPH) • Treatment of HypertensionTreatment of Hypertension 1.1 Benign Prostatic Hyperplasia (BPH) Doxazosin tablets are indicated for the treatment of the signs and symptoms of BPH. 1.2 Hypertension Doxazosin tablets are indicated for the treatment of hypertension, to lower blood pressure.
What it is
Doxazosin mesylate is a quinazoline compound that is a selective inhibitor of the alpha 1 subtype of alpha-adrenergic receptors.
Boxed warning
None in the current label
Causality screen of the 40 strongest signals
What the badges mean
- 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). 1,167 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Vascular anastomotic haemorrhage | 24 | 6,905.5 1,632.1–29,218.7ROR 6,910.2 · calibrated p 5e-15 ✓ | 373.4 EB05 264.0 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=24 · ♀ 0% (drug 34%) | not reported in cached trials |
| Spirometry abnormal | 285 | 556.0 472.6–654.0ROR 560.4 · calibrated p 2e-14 ✓ | 278.0 EB05 251.9 · IC025 +7.4 3/3 methods agree | Lab value / disease marker | serious n=285 · ♀ 0% (drug 34%) | not reported in cached trials |
| Mite allergy | 286 | 478.4 409.1–559.5ROR 482.3 · calibrated p 1e-13 ✓ | 257.2 EB05 233.1 · IC025 +7.3 3/3 methods agree | Not in label — unassessed | serious n=286 · ♀ 0% (drug 34%) | not reported in cached trials |
| Mycotic allergy | 286 | 301.4 261.3–347.7ROR 303.8 · calibrated p 1e-11 ✓ | 195.6 EB05 177.3 · IC025 +7.0 3/3 methods agree | Not in label — unassessed | serious n=286 · ♀ 0% (drug 34%) | not reported in cached trials |
| Dust allergy | 290 | 252.1 219.7–289.3ROR 254.1 · calibrated p 5e-11 ✓ | 173.6 EB05 157.5 · IC025 +6.9 3/3 methods agree | Not in label — unassessed | serious n=290 · ♀ 0% (drug 34%) | not reported in cached trials |
| Pulmonary vasculitis | 157 | 247.5 205.4–298.4ROR 248.6 · calibrated p 8e-11 ✓ | 169.8 EB05 148.7 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=157 · ♀ 0% (drug 34%) | not reported in cached trials |
| Vena cava injury | 26 | 241.3 152.7–381.4ROR 241.5 · calibrated p 5e-10 ✓ | 151.6 EB05 108.7 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 0% (drug 34%) | not reported in cached trials |
| Total lung capacity abnormal | 107 | 228.9 183.0–286.3ROR 229.6 · calibrated p 2e-10 ✓ | 159.4 EB05 135.6 · IC025 +6.2 3/3 methods agree | Not in label — unassessed | serious n=107 · ♀ 0% (drug 34%) | not reported in cached trials |
| Capillaritis | 70 | 206.6 157.2–271.4ROR 207.0 · calibrated p 6e-10 ✓ | 146.3 EB05 119.7 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=70 · ♀ 0% (drug 34%) | not reported in cached trials |
| Conjunctivitis allergic | 300 | 150.9 132.9–171.3ROR 152.2 · calibrated p 5e-9 ✓ | 118.9 EB05 108.0 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=300 · ♀ 0% (drug 34%) | not reported in cached trials |
| Renal cyst haemorrhage | 38 | 122.2 86.1–173.3ROR 122.3 · calibrated p 6e-8 ✓ | 96.2 EB05 73.2 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=38 · ♀ 0% (drug 34%) | not reported in cached trials |
| Antineutrophil cytoplasmic antibody positive | 117 | 111.8 91.8–136.3ROR 112.2 · calibrated p 6e-8 ✓ | 92.4 EB05 79.2 · IC025 +5.8 3/3 methods agree | Lab value / disease marker | serious n=117 · ♀ 0% (drug 34%) | not reported in cached trials |
| Renin increased | 31 | 74.3 51.1–108.0ROR 74.4 · calibrated p 2e-6 ✓ | 63.5 EB05 46.9 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=31 · 100% clinician | not reported in cached trials |
| Mycobacterium test positive | 23 | 73.5 47.6–113.5ROR 73.6 · calibrated p 3e-6 ✓ | 62.1 EB05 43.6 · IC025 +4.1 3/3 methods agree | Lab value / disease marker | serious n=23 · 100% clinician | not reported in cached trials |
| Neuritis | 162 | 68.7 58.4–80.8ROR 69.0 · calibrated p 2e-6 ✓ | 61.1 EB05 53.6 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious n=162 · ♀ 0% (drug 34%) | not reported in cached trials |
| Normochromic normocytic anaemia | 307 | 66.5 59.1–74.8ROR 67.1 · calibrated p 2e-6 ✓ | 59.5 EB05 54.1 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=306 · ♀ 0% (drug 34%) | not reported in cached trials |
| Abdominal wall haemorrhage | 24 | 59.8 39.3–91.0ROR 59.8 · calibrated p 1e-5 ✓ | 52.1 EB05 36.9 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=24 · ♀ 0% (drug 34%) · 100% clinician | not reported in cached trials |
| Carotid arteriosclerosis | 87 | 54.2 43.5–67.5ROR 54.3 · calibrated p 1e-5 ✓ | 49.1 EB05 41.0 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=87 · ♀ 13% (drug 34%) | not reported in cached trials |
| Cardiospasm | 45 | 51.2 37.7–69.4ROR 51.2 · calibrated p 2e-5 ✓ | 46.2 EB05 36.0 · IC025 +4.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=45 · ♀ 100% (drug 34%) | not reported in cached trials |
| Vascular compression | 25 | 51.0 33.9–76.8ROR 51.1 · calibrated p 3e-5 ✓ | 45.4 EB05 32.4 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=25 · ♀ 0% (drug 34%) | not reported in cached trials |
| Eosinophilic granulomatosis with polyangiitis | 153 | 47.9 40.6–56.4ROR 48.1 · calibrated p 2e-5 ✓ | 44.0 EB05 38.5 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=153 · ♀ 0% (drug 34%) | not reported in cached trials |
| Intraductal papillary mucinous neoplasm | 22 | 47.6 30.8–73.5ROR 47.6 · calibrated p 4e-5 ✓ | 42.5 EB05 29.6 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=22 · ♀ 0% (drug 34%) | not reported in cached trials |
| Rectal prolapse | 84 | 43.7 35.0–54.5ROR 43.8 · calibrated p 4e-5 ✓ | 40.3 EB05 33.6 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=84 · ♀ 58% (drug 34%) | not reported in cached trials |
| Immunisation | 29 | 41.8 28.7–61.0ROR 41.9 · calibrated p 7e-5 ✓ | 38.2 EB05 27.9 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=29 · ♀ 100% (drug 34%) | not reported in cached trials |
| Delayed graft function | 43 | 37.8 27.8–51.4ROR 37.8 · calibrated p 1e-4 ✓ | 35.0 EB05 27.1 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=43 · ♀ 0% (drug 34%) | not reported in cached trials |
| Renal artery stenosis | 84 | 37.6 30.2–46.9ROR 37.7 · calibrated p 9e-5 ✓ | 35.1 EB05 29.3 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=84 | not reported in cached trials |
| Palmoplantar keratoderma | 43 | 37.0 27.2–50.4ROR 37.1 · calibrated p 1e-4 ✓ | 34.4 EB05 26.6 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=43 · ♀ 100% (drug 34%) | not reported in cached trials |
| Phaeochromocytoma | 38 | 35.3 25.5–49.0ROR 35.4 · calibrated p 2e-4 ✓ | 32.8 EB05 25.0 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=37 · ♀ 56% (drug 34%) · 100% clinician | not reported in cached trials |
| Lung diffusion test decreased | 22 | 34.3 22.3–52.7ROR 34.3 · calibrated p 2e-4 ✓ | 31.6 EB05 22.0 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=22 · 100% clinician | not reported in cached trials |
| Respiratory symptom | 153 | 33.7 28.6–39.7ROR 33.8 · calibrated p 1e-4 ✓ | 31.8 EB05 27.8 · IC025 +4.6 3/3 methods agree | Labeled (related wording) related wording | serious n=153 · ♀ 0% (drug 34%) | not reported in cached trials |
| Hyperparathyroidism secondary | 131 | 31.8 26.7–37.9ROR 31.9 · calibrated p 2e-4 ✓ | 30.1 EB05 26.0 · IC025 +4.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=131 | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 46 | 26.1 19.4–35.0ROR 26.1 · calibrated p 7e-4 ✓ | 24.7 EB05 19.3 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=46 | not reported in cached trials |
| Nephrogenic anaemia | 193 | 25.1 21.8–29.0ROR 25.3 · calibrated p 7e-4 ✓ | 24.1 EB05 21.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=192 · 100% clinician | not reported in cached trials |
| Arteriosclerosis coronary artery | 267 | 24.6 21.7–27.8ROR 24.7 · calibrated p 7e-4 ✓ | 23.6 EB05 21.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=266 · ♀ 3% (drug 34%) | not reported in cached trials |
| Arteriosclerosis | 376 | 24.2 21.9–26.9ROR 24.5 · calibrated p 8e-4 ✓ | 23.3 EB05 21.4 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 16.6 · ♀ 6% (drug 34%) | not reported in cached trials |
| Forced expiratory volume decreased | 112 | 24.0 19.9–29.0ROR 24.0 · calibrated p 9e-4 ✓ | 23.0 EB05 19.6 · IC025 +4.1 3/3 methods agree | Lab value / disease marker | serious n=112 · ♀ 0% (drug 34%) | not reported in cached trials |
| Scrotal oedema | 27 | 23.0 15.7–33.8ROR 23.0 · calibrated p 0.001 ✓ | 21.9 EB05 15.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=27 · ♀ 0% (drug 34%) · 100% clinician | not reported in cached trials |
| Aortic dilatation | 39 | 21.6 15.7–29.8ROR 21.6 · calibrated p 0.002 ✓ | 20.7 EB05 15.8 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 0% (drug 34%) | not reported in cached trials |
| Erosive duodenitis | 26 | 19.6 13.3–29.0ROR 19.6 · calibrated p 0.003 ✓ | 18.7 EB05 13.3 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 0% (drug 34%) · 100% clinician | not reported in cached trials |
| Intervertebral disc space narrowing | 25 | 18.7 12.6–27.9ROR 18.7 · calibrated p 0.004 ✓ | 17.8 EB05 12.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=25 · ♀ 0% (drug 34%) | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Doxazosin 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 (0 of 40 signal terms matched).
- NCT01003886 — A Post Marketing Surveillance Study Of Doxazosin Mesylate GITS Among Filipino Patients With Benign Prostatic H (N=989, phase n/a; 9 AE terms posted; arms: Doxazosin GITS)
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 |
|---|---|---|---|---|---|---|
| Dyspnoea (shortness of breath) | 1,986 | 2.1 2.0–2.1ROR 2.1 · calibrated p 0.994 | 2.1 EB05 2.0 · IC025 +1.0 | Labeled adverse reaction exact term | serious PRR 1.8 | not reported in cached trials |
| Dizziness | 1,738 | 2.0 2.0–2.1ROR 2.1 · calibrated p 0.995 | 2.0 EB05 2.0 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 2.1 | NCT01003886: 7/989 (0.7%) on Doxazosin |
| Fatigue (tiredness) | 1,724 | 1.3 1.2–1.4ROR 1.3 · calibrated p 0.516 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.3 | not reported in cached trials |
| Diarrhoea (diarrhea) | 1,680 | 1.5 1.5–1.6ROR 1.6 · calibrated p 0.676 | 1.5 EB05 1.5 · IC025 +0.5 | Not in label — unassessed | serious PRR 1.4 | not reported in cached trials |
| Drug ineffective (drug did not work) | 1,606 | 0.7 0.7–0.7ROR 0.7 · calibrated p 0.130 | 0.7 EB05 0.7 · IC025 -0.6 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 0.9 | not reported in cached trials |
| Nausea | 1,480 | 1.1 1.0–1.2ROR 1.1 · calibrated p 0.373 | 1.1 EB05 1.0 · IC025 +0.0 | Not in label — unassessed | serious PRR 1.1 | not reported in cached trials |
| Hypotension (low blood pressure) | 1,309 | 3.8 3.6–4.0ROR 3.9 · calibrated p 0.388 | 3.8 EB05 3.6 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.9 | NCT01003886: 2/989 (0.2%) on Doxazosin |
| Asthenia (weakness) | 1,267 | 2.0 1.9–2.1ROR 2.0 · calibrated p 0.948 | 2.0 EB05 1.9 · IC025 +0.9 | Not in label — unassessed | serious PRR 1.7 | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 1,258 | 4.9 4.6–5.1ROR 5.0 · calibrated p 0.235 | 4.8 EB05 4.6 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | not reported in cached trials |
| Headache | 1,252 | 1.2 1.1–1.2ROR 1.2 · calibrated p 0.423 | 1.2 EB05 1.1 · IC025 +0.1 | Not in label — unassessed | serious PRR 1.4 | NCT01003886: 1/989 (0.1%) on Doxazosin |
| Hypertension (high blood pressure) | 1,153 | 3.2 3.0–3.4ROR 3.3 · calibrated p 0.548 | 3.2 EB05 3.0 · IC025 +1.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 2.5 | NCT01003886: 1/989 (0.1%) on Doxazosin |
| Drug interaction | 1,125 | 4.2 3.9–4.4ROR 4.3 · calibrated p 0.332 | 4.1 EB05 3.9 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious PRR 3.1 | not reported in cached trials |
| Vomiting | 1,064 | 1.3 1.3–1.4ROR 1.3 · calibrated p 0.533 | 1.3 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.2 | not reported in cached trials |
| Fall | 1,019 | 1.8 1.7–1.9ROR 1.8 · calibrated p 0.839 | 1.8 EB05 1.7 · IC025 +0.7 | Not in label — unassessed | serious PRR 1.4 | not reported in cached trials |
| Malaise (feeling unwell) | 1,008 | 1.3 1.3–1.4ROR 1.4 · calibrated p 0.542 | 1.3 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.4 | not reported in cached trials |
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.
- Vascular anastomotic haemorrhage — n=24, PRR 6,905.5
- Mite allergy — n=286, PRR 478.4
- Mycotic allergy — n=286, PRR 301.4
- Dust allergy — n=290, PRR 252.1
- Pulmonary vasculitis — n=157, PRR 247.5
- Vena cava injury — n=26, PRR 241.3
- Total lung capacity abnormal — n=107, PRR 228.9
- Capillaritis — n=70, PRR 206.6
- Conjunctivitis allergic — n=300, PRR 150.9
- Renal cyst haemorrhage — n=38, PRR 122.2
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 Doxazosin?
In FDA FAERS, the most frequently co-reported reaction terms for Doxazosin are dyspnoea, dizziness, fatigue, diarrhoea, nausea, hypotension. 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 Doxazosin have an FDA boxed warning?
No. The FDA label retrieved for Doxazosin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Doxazosin 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 08521333-ff21-45ad-b99e-1f43d945d24d, effective 20260424; matched on
openfda.generic_name.exact:"DOXAZOSIN") - 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, 1,207 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
DOXAZOSIN, 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.