OpenClaim

Doxazosin Side Effects

The most commonly reported side effects of doxazosin include dyspnoea, fatigue, and diarrhoea, based on 38,271 FDA adverse event reports from 2004 to 2025. 3.5% of reports found the drug to be ineffective.

Doxazosin side effects

Percentages show how often each reaction appears relative to total reports for doxazosin.

1
Dyspnoea4.4%1,698
2
Fatigue3.9%1,497
3
Diarrhoea3.7%1,431
4
Dizziness3.6%1,395
5
Drug Ineffective3.5%1,345
6
Acute Kidney Injury3.4%1,311
7
Nausea3.2%1,221
8
Hypotension2.8%1,085
9
Headache2.8%1,065
10
Asthenia2.7%1,026
11
Off Label Use2.6%993
12
Hypertension2.4%929
13
Drug Interaction2.4%910
14
Vomiting2.4%901
15
Malaise2.2%853

These are voluntary reports and do not establish that doxazosin caused these reactions.

Report severity

83.2%Serious31,856 reports
42.7%Hospitalizations16,354 reports
8.7%Fatal3,316 reports

Seriousness is determined by the reporter, not by OpenClaim.

Doxazosin drug interactions

Other drugs that appear in adverse event reports alongside doxazosin. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Amlodipine5.6%2,144
2
Lenalidomide3.1%1,181
3
Metformin2.8%1,076
4
Furosemide2.8%1,075
5
Aspirin2.6%997
6
Hydrochlorothiazide2.4%920
7
Omeprazole2.3%893
8
Pantoprazole-sodium2.3%884
9
Bisoprolol-fumarate2.3%880
10
Apixaban2.2%851
11
Atorvastatin-calcium2.2%823
12
Ramipril2.1%808
13
Prednisone1.8%704
14
Valsartan1.8%686
15
Lansoprazole1.7%647

Taken alongside

1
Aspirin21.8%8,326
2
Amlodipine21.3%8,156
3
Furosemide17.0%6,518
4
Atorvastatin-calcium16.6%6,349
5
Omeprazole13.0%4,986
6
Acetaminophen12.4%4,732
7
Metformin10.6%4,061
8
Simvastatin10.5%4,020
9
Metoprolol10.4%3,977
10
Levothyroxine-sodium9.8%3,764
11
Insulin8.8%3,370
12
Hydrochlorothiazide8.7%3,315
13
Lisinopril8.4%3,231
14
Allopurinol8.4%3,204
15
Losartan-potassium8.1%3,090

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports doxazosin side effects

31.5% of doxazosin adverse event reports involve female patients and 61.3% involve male patients. The largest age group is elderly at 67%. These figures reflect who reports side effects, not underlying risk.

Sex

Female31.5%
Male61.3%
Unknown7.2%

Age group

< 20.1%
2–110.3%
12–170.2%
18–6432.6%
65+66.7%

What is doxazosin used for

Conditions and purposes for which patients were taking doxazosin when the adverse event was reported.

Accelerated HypertensionAccidental ExposureAcute Myocardial InfarctionAdenoma BenignAdjuvant TherapyAdrenal Blockade TherapyAdrenal MassAdverse Drug ReactionAneurysmAngina PectorisAntibiotic ProphylaxisAntibiotic TherapyAntidepressant TherapyAnxietyAortic Aneurysm

Showing 15 of 451 indications

Doxazosin brand names and reporting trend

Doxazosin is sold under the brand name Doxazosin Mesylate.

Brand names

Doxazosin Mesylate8

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking doxazosin with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.