Doxazosin side effects: what 27,818 FDA adverse event reports show
Drug class
Not stated in label
Who reports
27,818 reports · 83% serious · 2,312 with death outcome · 35% 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). 1,158 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 |
|---|---|---|---|---|---|---|
| Spirometry abnormal | 143 | 243.1 201.3–293.5ROR 244.3 · calibrated p 9e-11 ✓ | 179.0 EB05 155.7 · IC025 +6.5 3/3 methods agree | Lab value / disease marker | serious n=143 · ♀ 0% (drug 35%) | no trial data cached |
| Pulmonary vasculitis | 120 | 221.7 180.9–271.8ROR 222.7 · calibrated p 2e-10 ✓ | 166.5 EB05 143.0 · IC025 +6.3 3/3 methods agree | Not in label — unassessed | serious n=120 · ♀ 0% (drug 35%) | no trial data cached |
| Mite allergy | 143 | 218.1 181.1–262.7ROR 219.2 · calibrated p 2e-10 ✓ | 165.1 EB05 143.6 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=143 · ♀ 0% (drug 35%) | no trial data cached |
| Total lung capacity abnormal | 81 | 204.0 159.5–260.7ROR 204.5 · calibrated p 6e-10 ✓ | 154.5 EB05 128.2 · IC025 +6.0 3/3 methods agree | Not in label — unassessed | serious n=81 · ♀ 0% (drug 35%) | no trial data cached |
| Vena cava injury | 18 | 191.0 113.8–320.6ROR 191.1 · calibrated p 6e-9 ✓ | 131.3 EB05 87.9 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Capillaritis | 53 | 185.7 137.5–250.9ROR 186.1 · calibrated p 2e-9 ✓ | 141.3 EB05 112.1 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=53 · ♀ 0% (drug 35%) | no trial data cached |
| Mycotic allergy | 143 | 154.2 128.8–184.5ROR 155.0 · calibrated p 5e-9 ✓ | 125.7 EB05 109.4 · IC025 +6.2 3/3 methods agree | Not in label — unassessed | serious n=143 · ♀ 0% (drug 35%) | no trial data cached |
| Dust allergy | 146 | 134.6 112.9–160.4ROR 135.3 · calibrated p 1e-8 ✓ | 112.4 EB05 97.9 · IC025 +6.1 3/3 methods agree | Not in label — unassessed | serious n=146 · ♀ 0% (drug 35%) | no trial data cached |
| Antineutrophil cytoplasmic antibody positive | 91 | 107.6 86.4–134.1ROR 108.0 · calibrated p 9e-8 ✓ | 92.4 EB05 77.5 · IC025 +5.6 3/3 methods agree | Lab value / disease marker | serious n=91 · ♀ 0% (drug 35%) | no trial data cached |
| Renin increased | 30 | 92.5 63.3–135.1ROR 92.6 · calibrated p 5e-7 ✓ | 78.4 EB05 57.5 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=30 · 100% clinician | no trial data cached |
| Renal cyst haemorrhage | 23 | 88.1 57.2–135.7ROR 88.1 · calibrated p 9e-7 ✓ | 74.2 EB05 52.1 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=23 · ♀ 0% (drug 35%) | no trial data cached |
| Conjunctivitis allergic | 152 | 87.4 73.9–103.3ROR 87.9 · calibrated p 4e-7 ✓ | 77.6 EB05 67.7 · IC025 +5.7 3/3 methods agree | Not in label — unassessed | serious n=152 · ♀ 0% (drug 35%) | no trial data cached |
| Neuritis | 125 | 66.6 55.5–80.0ROR 66.9 · calibrated p 2e-6 ✓ | 60.7 EB05 52.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=125 · ♀ 0% (drug 35%) | no trial data cached |
| Cardiospasm | 45 | 66.1 48.7–89.6ROR 66.2 · calibrated p 4e-6 ✓ | 59.3 EB05 46.1 · IC025 +4.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=45 · ♀ 100% (drug 35%) | no trial data cached |
| Gastrointestinal tract mucosal pigmentation | 21 | 64.2 41.1–100.2ROR 64.2 · calibrated p 7e-6 ✓ | 56.3 EB05 38.9 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=20 · 100% clinician | no trial data cached |
| Immunisation | 29 | 54.0 37.0–78.7ROR 54.0 · calibrated p 2e-5 ✓ | 48.9 EB05 35.7 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=29 · ♀ 100% (drug 35%) | no trial data cached |
| Palmoplantar keratoderma | 43 | 47.8 35.1–65.1ROR 47.9 · calibrated p 3e-5 ✓ | 44.2 EB05 34.2 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=43 · ♀ 100% (drug 35%) | no trial data cached |
| Carotid arteriosclerosis | 60 | 46.9 36.1–60.8ROR 47.0 · calibrated p 3e-5 ✓ | 43.6 EB05 35.1 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=60 · ♀ 13% (drug 35%) | no trial data cached |
| Vascular compression | 18 | 46.3 28.7–74.5ROR 46.3 · calibrated p 6e-5 ✓ | 41.8 EB05 28.0 · IC025 +3.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=18 | no trial data cached |
| Eosinophilic granulomatosis with polyangiitis | 116 | 45.9 38.1–55.4ROR 46.1 · calibrated p 3e-5 ✓ | 43.0 EB05 36.8 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=116 · ♀ 0% (drug 35%) | no trial data cached |
| Phaeochromocytoma | 36 | 43.1 30.8–60.2ROR 43.1 · calibrated p 5e-5 ✓ | 40.0 EB05 30.2 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=35 · 100% clinician | no trial data cached |
| Normochromic normocytic anaemia | 157 | 41.6 35.4–48.8ROR 41.8 · calibrated p 4e-5 ✓ | 39.2 EB05 34.4 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=157 · ♀ 0% (drug 35%) | no trial data cached |
| Lower urinary tract symptoms | 17 | 38.3 23.5–62.3ROR 38.3 · calibrated p 2e-4 ✓ | 35.1 EB05 23.2 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=17 | no trial data cached |
| Hyperparathyroidism secondary | 115 | 35.8 29.7–43.2ROR 36.0 · calibrated p 1e-4 ✓ | 34.1 EB05 29.1 · IC025 +4.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=115 | no trial data cached |
| Renal artery stenosis | 60 | 34.1 26.3–44.1ROR 34.1 · calibrated p 2e-4 ✓ | 32.3 EB05 26.0 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=60 | no trial data cached |
| Respiratory symptom | 119 | 33.4 27.8–40.1ROR 33.5 · calibrated p 2e-4 ✓ | 31.9 EB05 27.3 · IC025 +4.5 3/3 methods agree | Labeled (related wording) related wording | serious n=119 · ♀ 0% (drug 35%) | no trial data cached |
| Delayed graft function | 29 | 32.2 22.2–46.7ROR 32.2 · calibrated p 3e-4 ✓ | 30.4 EB05 22.2 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=29 | no trial data cached |
| Chronic kidney disease-mineral and bone disorder | 44 | 32.1 23.7–43.4ROR 32.2 · calibrated p 2e-4 ✓ | 30.5 EB05 23.6 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=44 | no trial data cached |
| Rectal prolapse | 48 | 31.2 23.4–41.6ROR 31.2 · calibrated p 3e-4 ✓ | 29.7 EB05 23.3 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=48 | no trial data cached |
| Nephrogenic anaemia | 177 | 29.6 25.5–34.4ROR 29.8 · calibrated p 3e-4 ✓ | 28.5 EB05 25.1 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=176 | no trial data cached |
| Gravitational oedema | 21 | 23.2 15.1–35.9ROR 23.3 · calibrated p 0.002 ✓ | 22.1 EB05 15.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=21 · 100% clinician | no trial data cached |
| Scrotal oedema | 21 | 22.9 14.8–35.4ROR 22.9 · calibrated p 0.002 ✓ | 21.8 EB05 15.0 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=21 · 100% clinician | no trial data cached |
| Forced expiratory volume decreased | 83 | 22.7 18.2–28.2ROR 22.8 · calibrated p 0.001 ✓ | 22.0 EB05 18.3 · IC025 +3.9 3/3 methods agree | Lab value / disease marker | serious n=83 · ♀ 0% (drug 35%) | no trial data cached |
| Aortic dilatation | 28 | 19.8 13.6–28.9ROR 19.8 · calibrated p 0.003 ✓ | 19.1 EB05 13.8 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 0% (drug 35%) | no trial data cached |
| Erosive duodenitis | 20 | 19.3 12.4–30.1ROR 19.4 · calibrated p 0.004 ✓ | 18.5 EB05 12.4 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=20 | no trial data cached |
| Arteriosclerosis | 233 | 19.1 16.8–21.7ROR 19.2 · calibrated p 0.002 ✓ | 18.6 EB05 16.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 13.1 · ♀ 6% (drug 35%) | no trial data cached |
| Arteriosclerosis coronary artery | 156 | 18.2 15.5–21.3ROR 18.3 · calibrated p 0.003 ✓ | 17.8 EB05 15.5 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=155 · ♀ 4% (drug 35%) | no trial data cached |
| Pulmonary alveolar haemorrhage | 127 | 17.5 14.7–20.8ROR 17.5 · calibrated p 0.004 ✓ | 17.0 EB05 14.7 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=127 · ♀ 0% (drug 35%) | no trial data cached |
| Neurological symptom | 128 | 17.4 14.6–20.7ROR 17.4 · calibrated p 0.004 ✓ | 17.0 EB05 14.6 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=128 · ♀ 0% (drug 35%) | no trial data cached |
| Atrial tachycardia | 46 | 16.8 12.5–22.5ROR 16.8 · calibrated p 0.005 ✓ | 16.3 EB05 12.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=46 · ♀ 100% (drug 35%) | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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) | 1,517 | 2.0 1.9–2.1ROR 2.1 · calibrated p 0.989 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 1.8 | no trial data cached |
| Dizziness | 1,340 | 2.0 1.9–2.1ROR 2.1 · calibrated p 0.989 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 2.1 | no trial data cached |
| Fatigue (tiredness) | 1,312 | 1.3 1.2–1.3ROR 1.3 · calibrated p 0.499 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.2 | no trial data cached |
| Diarrhoea (diarrhea) | 1,284 | 1.5 1.4–1.6ROR 1.5 · calibrated p 0.661 | 1.5 EB05 1.4 · IC025 +0.5 | Not in label — unassessed | serious PRR 1.4 | no trial data cached |
| Drug ineffective (drug did not work) | 1,281 | 0.7 0.7–0.8ROR 0.7 · calibrated p 0.141 | 0.7 EB05 0.7 · IC025 -0.5 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 0.9 | no trial data cached |
| Nausea | 1,172 | 1.1 1.1–1.2ROR 1.1 · calibrated p 0.390 | 1.1 EB05 1.1 · IC025 +0.1 | Not in label — unassessed | serious PRR 1.1 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 1,167 | 5.8 5.5–6.1ROR 6.0 · calibrated p 0.149 | 5.8 EB05 5.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Hypotension (low blood pressure) | 1,001 | 3.8 3.6–4.0ROR 3.9 · calibrated p 0.400 | 3.8 EB05 3.6 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.9 | no trial data cached |
| Headache | 983 | 1.2 1.1–1.3ROR 1.2 · calibrated p 0.434 | 1.2 EB05 1.1 · IC025 +0.1 | Not in label — unassessed | serious PRR 1.4 | no trial data cached |
| Asthenia (weakness) | 957 | 1.9 1.8–2.0ROR 2.0 · calibrated p 0.918 | 1.9 EB05 1.8 · IC025 +0.8 | Not in label — unassessed | serious PRR 1.6 | no trial data cached |
| Hypertension (high blood pressure) | 893 | 3.2 3.0–3.4ROR 3.3 · calibrated p 0.549 | 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 | no trial data cached |
| Drug interaction | 881 | 4.2 3.9–4.5ROR 4.3 · calibrated p 0.325 | 4.2 EB05 4.0 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 3.1 | no trial data cached |
| Vomiting | 858 | 1.4 1.3–1.5ROR 1.4 · calibrated p 0.570 | 1.4 EB05 1.3 · IC025 +0.4 | Labeled adverse reaction exact term | serious PRR 1.3 | no trial data cached |
| Off label use (used outside approved label) | 817 | 0.7 0.7–0.8ROR 0.7 · calibrated p 0.131 | 0.7 EB05 0.7 · IC025 -0.6 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 0.7 | no trial data cached |
| Malaise (feeling unwell) | 789 | 1.4 1.3–1.5ROR 1.4 · calibrated p 0.551 | 1.4 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | 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.
- Pulmonary vasculitis — n=120, PRR 221.7
- Mite allergy — n=143, PRR 218.1
- Total lung capacity abnormal — n=81, PRR 204.0
- Capillaritis — n=53, PRR 185.7
- Mycotic allergy — n=143, PRR 154.2
- Dust allergy — n=146, PRR 134.6
- Renin increased — n=30, PRR 92.5
- Renal cyst haemorrhage — n=23, PRR 88.1
- Conjunctivitis allergic — n=152, PRR 87.4
- Neuritis — n=125, PRR 66.6
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 Doxazosin?
In FDA FAERS, the most frequently co-reported reaction terms for Doxazosin are dyspnoea, dizziness, fatigue, diarrhoea, nausea, 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 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, 1,198 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 2026-10-14. 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.