Tamsulosin side effects: what 20,265 FDA adverse event reports show
Drug class
Alpha 1 adrenoceptor antagonist
Label matched
Tamsulosin Hydrochloride (Tamsulosin Hydrochloride)
Who reports
20,265 reports · 75% serious · 2,204 with death outcome · 5% female
Used for
Tamsulosin Hydrochloride Capsules are indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH) [ see Clinical Studies (14) ]. Tamsulosin Hydrochloride Capsules are not indicated for the treatment of hypertension. • Ta.
What it is
Tamsulosin hydrochloride is an antagonist of alpha 1A adrenoceptors in the prostate. Tamsulosin hydrochloride is (-)-( R )-5-[2-[[2-( o -Ethoxyphenoxy) ethyl]amino]propyl]-2 methoxybenzenesulfonamide,monohydrochloride.
Boxed warning
None in the current label
Causality screen of the 40 strongest signals
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.
- 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.
- 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, 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). 1,138 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 | 22 | 5,604.5 1,931.5–16,262.3ROR 5,610.6 · calibrated p 4e-18 ✓ | 492.0 EB05 342.5 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=22 | not reported in cached trials |
| Right atrial hypertrophy | 65 | 1,471.9 1,006.7–2,152.0ROR 1,476.6 · calibrated p 3e-18 ✓ | 511.5 EB05 415.4 · IC025 +6.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=65 | not reported in cached trials |
| Radiation inflammation | 37 | 876.8 565.1–1,360.5ROR 878.4 · calibrated p 2e-15 ✓ | 379.0 EB05 287.2 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=37 | not reported in cached trials |
| Congenital hiatus hernia | 80 | 586.5 445.6–771.9ROR 588.8 · calibrated p 3e-14 ✓ | 342.1 EB05 283.7 · IC025 +6.4 3/3 methods agree | Not in label — unassessed | serious n=80 | not reported in cached trials |
| Fractional exhaled nitric oxide increased | 59 | 536.8 391.7–735.5ROR 538.4 · calibrated p 1e-13 ✓ | 315.9 EB05 253.8 · IC025 +6.0 3/3 methods agree | Not in label — unassessed | serious n=59 | not reported in cached trials |
| Perineal cyst | 17 | 333.1 192.7–575.9ROR 333.4 · calibrated p 8e-11 ✓ | 196.2 EB05 129.7 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Pulmonary vasculitis | 128 | 331.0 271.3–403.9ROR 333.1 · calibrated p 5e-12 ✓ | 241.1 EB05 208.1 · IC025 +6.7 3/3 methods agree | Not in label — unassessed | serious n=128 | not reported in cached trials |
| Vena cava injury | 20 | 299.7 182.1–493.3ROR 300.0 · calibrated p 1e-10 ✓ | 190.0 EB05 129.9 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=20 | not reported in cached trials |
| Total lung capacity abnormal | 78 | 266.7 207.9–342.1ROR 267.7 · calibrated p 5e-11 ✓ | 201.2 EB05 166.4 · IC025 +6.1 3/3 methods agree | Not in label — unassessed | serious n=78 | not reported in cached trials |
| Amaurosis fugax | 216 | 262.0 225.8–304.1ROR 264.8 · calibrated p 4e-11 ✓ | 204.9 EB05 182.9 · IC025 +6.9 3/3 methods agree | Not in label — unassessed | serious n=216 · 93% clinician | not reported in cached trials |
| Capillaritis | 43 | 197.4 142.4–273.5ROR 197.8 · calibrated p 1e-9 ✓ | 154.3 EB05 119.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=43 | not reported in cached trials |
| Renal cyst haemorrhage | 28 | 151.0 101.5–224.5ROR 151.2 · calibrated p 2e-8 ✓ | 120.9 EB05 87.8 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=28 | not reported in cached trials |
| Spirometry abnormal | 73 | 146.7 114.8–187.4ROR 147.2 · calibrated p 9e-9 ✓ | 124.3 EB05 102.1 · IC025 +5.7 3/3 methods agree | Lab value / disease marker | serious n=73 | not reported in cached trials |
| Mite allergy | 67 | 121.3 94.2–156.2ROR 121.7 · calibrated p 4e-8 ✓ | 105.3 EB05 85.8 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=65 | not reported in cached trials |
| Steroid dependence | 87 | 117.9 94.5–147.1ROR 118.4 · calibrated p 4e-8 ✓ | 103.4 EB05 86.4 · IC025 +5.7 3/3 methods agree | Not in label — unassessed | serious n=87 · 93% clinician | not reported in cached trials |
| Malignant melanoma stage 0 | 18 | 113.9 70.0–185.4ROR 114.0 · calibrated p 2e-7 ✓ | 92.8 EB05 62.1 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Catarrh | 84 | 107.8 86.1–134.9ROR 108.2 · calibrated p 9e-8 ✓ | 95.5 EB05 79.6 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=84 · 94% clinician | not reported in cached trials |
| Bronchial wall thickening | 67 | 105.2 81.8–135.2ROR 105.5 · calibrated p 1e-7 ✓ | 93.0 EB05 75.8 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious n=67 | not reported in cached trials |
| Antineutrophil cytoplasmic antibody positive | 62 | 96.2 74.1–124.7ROR 96.5 · calibrated p 2e-7 ✓ | 85.7 EB05 69.2 · IC025 +5.3 3/3 methods agree | Lab value / disease marker | serious n=62 | not reported in cached trials |
| Mycotic allergy | 66 | 87.8 68.3–112.9ROR 88.1 · calibrated p 4e-7 ✓ | 79.1 EB05 64.4 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=66 | not reported in cached trials |
| Abdominal wall haemorrhage | 20 | 86.7 54.9–136.9ROR 86.8 · calibrated p 1e-6 ✓ | 74.5 EB05 50.9 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=20 | not reported in cached trials |
| Neuritis | 116 | 84.3 69.8–101.8ROR 84.7 · calibrated p 5e-7 ✓ | 76.9 EB05 65.9 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=116 | NCT00090103: 1/1,610 (0.1%) on Tamsulosin (serious AE) |
| Right ventricular hypertrophy | 65 | 79.4 61.7–102.2ROR 79.7 · calibrated p 9e-7 ✓ | 72.2 EB05 58.7 · IC025 +5.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=65 | not reported in cached trials |
| Dust allergy | 68 | 78.4 61.3–100.3ROR 78.6 · calibrated p 9e-7 ✓ | 71.5 EB05 58.3 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=66 | not reported in cached trials |
| Vascular compression | 21 | 74.8 48.0–116.5ROR 74.9 · calibrated p 3e-6 ✓ | 65.8 EB05 45.4 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=21 | not reported in cached trials |
| Intraductal papillary mucinous neoplasm | 18 | 67.9 42.2–109.4ROR 68.0 · calibrated p 6e-6 ✓ | 59.9 EB05 40.1 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Sars-cov-2 antibody test positive | 15 | 60.4 35.9–101.7ROR 60.5 · calibrated p 1e-5 ✓ | 53.4 EB05 34.4 · IC025 +3.5 3/3 methods agree | Lab value / disease marker | serious n=15 | not reported in cached trials |
| Blood 25-hydroxycholecalciferol decreased | 16 | 59.9 36.2–99.2ROR 60.0 · calibrated p 1e-5 ✓ | 53.3 EB05 34.8 · IC025 +3.6 3/3 methods agree | Lab value / disease marker | serious n=16 | not reported in cached trials |
| Bronchial secretion retention | 66 | 56.9 44.4–72.9ROR 57.1 · calibrated p 8e-6 ✓ | 53.2 EB05 43.2 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=66 | not reported in cached trials |
| Benign prostatic hyperplasia | 262 | 55.0 48.6–62.3ROR 55.7 · calibrated p 7e-6 ✓ | 52.1 EB05 47.0 · IC025 +5.4 3/3 methods agree | Likely indication confounding term in indications | serious n=257 | NCT00090103: 10/1,611 (0.6%) on Tamsulosin (serious AE) |
| Conjunctivitis allergic | 73 | 54.3 42.9–68.6ROR 54.4 · calibrated p 1e-5 ✓ | 50.9 EB05 41.8 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=73 | not reported in cached trials |
| Burns second degree | 87 | 54.1 43.6–67.0ROR 54.3 · calibrated p 1e-5 ✓ | 50.8 EB05 42.5 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=87 · 93% clinician | not reported in cached trials |
| Obstructive sleep apnoea syndrome | 68 | 52.9 41.5–67.5ROR 53.1 · calibrated p 1e-5 ✓ | 49.7 EB05 40.5 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=68 | not reported in cached trials |
| Eosinophilic granulomatosis with polyangiitis | 97 | 52.1 42.5–63.9ROR 52.4 · calibrated p 1e-5 ✓ | 49.2 EB05 41.5 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=97 | not reported in cached trials |
| Urinary tract disorder | 203 | 48.8 42.4–56.2ROR 49.3 · calibrated p 2e-5 ✓ | 46.4 EB05 41.3 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=198 · 90% clinician | NCT00090103: 1/1,623 (0.1%) on Tamsulosin (serious AE) |
| Malignant melanoma in situ | 56 | 48.0 36.8–62.8ROR 48.2 · calibrated p 2e-5 ✓ | 45.3 EB05 36.2 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=56 · 91% clinician | not reported in cached trials |
| Respiratory symptom | 122 | 47.0 39.2–56.4ROR 47.3 · calibrated p 2e-5 ✓ | 44.7 EB05 38.4 · IC025 +5.0 3/3 methods agree | Labeled adverse reaction exact term | serious n=122 | not reported in cached trials |
| Pulmonary function test abnormal | 68 | 47.0 36.9–59.9ROR 47.2 · calibrated p 3e-5 ✓ | 44.5 EB05 36.3 · IC025 +4.7 3/3 methods agree | Reporting / coding artifact | serious n=68 | not reported in cached trials |
| Myoglobin blood increased | 66 | 46.4 36.3–59.4ROR 46.6 · calibrated p 3e-5 ✓ | 43.9 EB05 35.7 · IC025 +4.7 3/3 methods agree | Lab value / disease marker | serious n=66 | not reported in cached trials |
| Retrograde ejaculation | 32 | 44.8 31.4–63.8ROR 44.9 · calibrated p 4e-5 ✓ | 42.0 EB05 31.1 · IC025 +4.1 3/3 methods agree | Labeled adverse reaction exact term | serious n=31 · 71% consumer | 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 Tamsulosin 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 (3 of 40 signal terms matched).
- NCT00090103 — Benign Prostatic Hyperplasia Trial With Dutasteride And Tamsulosin Combination Treatment (N=4844, PHASE3; 513 AE terms posted; arms: Combination; Dutasteride 0.5 mg; Tamsulosin 0.4 mg)
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) | 1,513 | 2.0 1.9–2.1ROR 2.1 · calibrated p 0.996 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled (related wording) related wording | serious PRR 1.9 | NCT00090103: 1/1,611 (0.1%) on Tamsulosin (serious AE) |
| Dyspnoea (shortness of breath) | 1,442 | 2.6 2.5–2.8ROR 2.8 · calibrated p 0.708 | 2.6 EB05 2.5 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.5 | NCT00090103: 1/1,611 (0.1%) on Tamsulosin (serious AE) |
| Dizziness | 1,235 | 2.6 2.4–2.7ROR 2.7 · calibrated p 0.744 | 2.6 EB05 2.4 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.6 | NCT00090103: 1/1,611 (0.1%) on Tamsulosin (serious AE) |
| Diarrhoea (diarrhea) | 1,229 | 2.0 1.9–2.1ROR 2.0 · calibrated p 0.966 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 1.9 | NCT00090103: 1/1,610 (0.1%) on Tamsulosin (serious AE) |
| Off label use (used outside approved label) | 1,047 | 1.2 1.2–1.3ROR 1.3 · calibrated p 0.482 | 1.2 EB05 1.2 · IC025 +0.2 | Reporting / coding artifact | serious PRR 1.4 | not reported in cached trials |
| Drug ineffective (drug did not work) | 977 | 0.8 0.7–0.8ROR 0.8 · calibrated p 0.159 | 0.8 EB05 0.7 · IC025 -0.5 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 0.9 | not reported in cached trials |
| Headache | 966 | 1.6 1.5–1.7ROR 1.6 · calibrated p 0.723 | 1.6 EB05 1.5 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.9 | not reported in cached trials |
| Fall | 905 | 2.8 2.6–3.0ROR 2.9 · calibrated p 0.659 | 2.8 EB05 2.7 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 2.4 | NCT00090103: 1/1,623 (0.1%) on Tamsulosin (serious AE) |
| Asthenia (weakness) | 900 | 2.5 2.3–2.6ROR 2.5 · calibrated p 0.794 | 2.5 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.2 | NCT00090103: 1/1,610 (0.1%) on Tamsulosin (serious AE) |
| Nausea | 874 | 1.1 1.1–1.2ROR 1.2 · calibrated p 0.408 | 1.1 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 1.2 | not reported in cached trials |
| Cough | 815 | 3.0 2.8–3.2ROR 3.1 · calibrated p 0.595 | 3.0 EB05 2.8 · IC025 +1.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | not reported in cached trials |
| Pruritus (itching) | 734 | 2.0 1.9–2.2ROR 2.0 · calibrated p 0.970 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 2.5 | not reported in cached trials |
| Arthralgia (joint pain) | 707 | 1.8 1.6–1.9ROR 1.8 · calibrated p 0.826 | 1.8 EB05 1.7 · IC025 +0.7 | Not in label — unassessed | serious PRR 1.9 | NCT00090103: 3/1,611 (0.2%) on Tamsulosin (serious AE) |
| Death | 703 | 0.8 0.8–0.9ROR 0.8 · calibrated p 0.206 | 0.8 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction | serious PRR 0.6 | NCT00090103: 1/1,611 (0.1%) on Tamsulosin (serious AE) |
| Malaise (feeling unwell) | 700 | 1.6 1.5–1.8ROR 1.7 · calibrated p 0.751 | 1.6 EB05 1.5 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.8 | NCT00090103: 1/1,611 (0.1%) on Tamsulosin (serious AE) |
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=22, PRR 5,604.5
- Radiation inflammation — n=37, PRR 876.8
- Congenital hiatus hernia — n=80, PRR 586.5
- Fractional exhaled nitric oxide increased — n=59, PRR 536.8
- Pulmonary vasculitis — n=128, PRR 331.0
- Vena cava injury — n=20, PRR 299.7
- Total lung capacity abnormal — n=78, PRR 266.7
- Amaurosis fugax — n=216, PRR 262.0
- Capillaritis — n=43, PRR 197.4
- Renal cyst haemorrhage — n=28, PRR 151.0
✓ A hand-written Bradford Hill causality assessment exists for this drug: Oxycodone Hydrochloride ↔ Drug Dependence.
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 Tamsulosin?
In FDA FAERS, the most frequently co-reported reaction terms for Tamsulosin are fatigue, dyspnoea, dizziness, diarrhoea, headache, fall. 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 Tamsulosin have an FDA boxed warning?
No. The FDA label retrieved for Tamsulosin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Tamsulosin 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 06b44e53-c6e7-4e12-a8fd-572d092cfa70, effective 20200201; matched on
openfda.generic_name.exact:"TAMSULOSIN HYDROCHLORIDE") - 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, 1,178 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
TAMSULOSIN, 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.