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Hydrochlorothiazide Side Effects

The most commonly reported side effects of hydrochlorothiazide include fatigue, nausea, and diarrhoea, based on 279,493 FDA adverse event reports from 2004 to 2025. 4.7% of reports found the drug to be ineffective.

Hydrochlorothiazide side effects

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

1
Fatigue4.9%13,591
2
Drug Ineffective4.7%13,136
3
Nausea4.6%12,830
4
Diarrhoea4.3%12,085
5
Headache3.6%10,017
6
Dyspnoea3.6%10,017
7
Dizziness3.5%9,777
8
Pain3.5%9,668
9
Off Label Use3.4%9,369
10
Acute Kidney Injury3.3%9,146
11
Arthralgia2.9%8,176
12
Malaise2.8%7,872
13
Fall2.8%7,725
14
Vomiting2.7%7,561
15
Asthenia2.6%7,326

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

Report severity

71.5%Serious199,862 reports
36.7%Hospitalizations102,648 reports
7.4%Fatal20,548 reports

Seriousness is determined by the reporter, not by OpenClaim.

Hydrochlorothiazide drug interactions

Other drugs that appear in adverse event reports alongside hydrochlorothiazide. 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
Valsartan5.1%14,254
2
Adalimumab4.3%12,056
3
Metformin4.1%11,366
4
Amlodipine3.9%10,796
5
Lenalidomide2.9%7,973
6
Omeprazole2.7%7,477
7
Atorvastatin-calcium2.3%6,337
8
Olmesartan-medoxomil2.2%6,234
9
Lisinopril2.2%6,051
10
Esomeprazole2.0%5,620
11
Pantoprazole-sodium1.9%5,228
12
Pregabalin1.8%4,998
13
Aspirin1.7%4,884
14
Etanercept1.6%4,597
15
Losartan-potassium1.6%4,573

Taken alongside

1
Aspirin18.5%51,793
2
Amlodipine15.0%41,843
3
Metformin14.5%40,614
4
Acetaminophen12.9%36,123
5
Lisinopril12.8%35,907
6
Atorvastatin-calcium12.8%35,764
7
Levothyroxine-sodium12.3%34,281
8
Metoprolol10.9%30,526
9
Ergocalciferol10.7%29,869
10
Omeprazole10.7%29,775
11
Losartan-potassium10.5%29,220
12
Simvastatin9.0%25,091
13
Albuterol7.5%20,997
14
Gabapentin7.0%19,539
15
Furosemide6.8%19,012

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 hydrochlorothiazide side effects

58.0% of hydrochlorothiazide adverse event reports involve female patients and 34.9% involve male patients. The largest age group is elderly at 54%. These figures reflect who reports side effects, not underlying risk.

Sex

Female58.0%
Male34.9%
Unknown7.2%

Age group

< 20.3%
2–110.2%
12–170.2%
18–6444.9%
65+54.4%

What is hydrochlorothiazide used for

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

Abdominal DistensionAbdominal PainAbdominal Pain UpperAccidental ExposureAccidental Exposure To Product By ChildAccidental OverdoseAcneAcute Coronary SyndromeAcute Hepatitis BAcute Kidney InjuryAcute Left Ventricular FailureAcute Lymphocytic LeukaemiaAcute Myeloid LeukaemiaAcute Myocardial InfarctionAcute Pulmonary Oedema

Showing 15 of 1,304 indications

Hydrochlorothiazide brand names and reporting trend

Hydrochlorothiazide is sold under the brand name Hydralazine Hydrochloride W/ Hydrochlorothiazide 50/50.

Brand names

Hydralazine Hydrochloride W/ Hydrochlorothiazide 50/50156,791

Quarterly reports (20042025)

20052010201520202025

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

Taking hydrochlorothiazide with another medication?

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