OpenClaim

Losartan Side Effects

The most commonly reported side effects of losartan include fatigue, diarrhoea, and nausea, based on 207,848 FDA adverse event reports from 2004 to 2025. 5.0% of reports found the drug to be ineffective.

Losartan side effects

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

1
Fatigue6.3%13,149
2
Diarrhoea5.3%10,917
3
Drug Ineffective5.0%10,461
4
Nausea4.9%10,193
5
Dyspnoea4.4%9,194
6
Dizziness4.2%8,831
7
Headache4.2%8,645
8
Pain3.9%8,103
9
Off Label Use3.8%7,860
10
Arthralgia3.4%6,995
11
Malaise3.1%6,432
12
Asthenia3.1%6,395
13
Cough2.8%5,896
14
Fall2.8%5,837
15
Vomiting2.7%5,584

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

Report severity

64.0%Serious133,107 reports
30.8%Hospitalizations64,079 reports
7.3%Fatal15,263 reports

Seriousness is determined by the reporter, not by OpenClaim.

Losartan drug interactions

Other drugs that appear in adverse event reports alongside losartan. 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
Lenalidomide4.4%9,059
2
Adalimumab4.2%8,694
3
Omeprazole2.8%5,774
4
Hydrochlorothiazide2.3%4,759
5
Esomeprazole2.2%4,523
6
Dupilumab2.1%4,291
7
Amlodipine1.9%4,028
8
Apixaban1.8%3,752
9
Metformin1.7%3,548
10
Pantoprazole-sodium1.7%3,463
11
Lansoprazole1.6%3,349
12
Atorvastatin-calcium1.6%3,237
13
Etanercept1.4%2,956
14
Rivaroxaban1.4%2,904
15
Insulin1.2%2,570

Taken alongside

1
Aspirin20.9%43,436
2
Amlodipine17.9%37,257
3
Atorvastatin-calcium17.5%36,309
4
Levothyroxine-sodium14.7%30,501
5
Ergocalciferol14.3%29,809
6
Metformin14.2%29,464
7
Metoprolol14.1%29,271
8
Hydrochlorothiazide14.0%29,075
9
Furosemide13.4%27,807
10
Omeprazole13.4%27,790
11
Acetaminophen13.2%27,408
12
Albuterol9.3%19,285
13
Gabapentin9.2%19,079
14
Simvastatin9.0%18,757
15
Insulin8.5%17,567

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 losartan side effects

56.3% of losartan adverse event reports involve female patients and 37.0% involve male patients. The largest age group is elderly at 59%. These figures reflect who reports side effects, not underlying risk.

Sex

Female56.3%
Male37.0%
Unknown6.7%

Age group

< 20.1%
2–110.2%
12–170.2%
18–6440.5%
65+59.0%

What is losartan used for

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

Abdominal PainAccidental ExposureAccidental Exposure To ProductAcute Coronary SyndromeAcute Kidney InjuryAcute Myocardial InfarctionAdenocarcinoma PancreasAdjuvant TherapyAdverse EventAffective DisorderAlanine Aminotransferase IncreasedAlbuminuriaAlopeciaAmyloidosisAnaemia

Showing 15 of 928 indications

Losartan brand names and reporting trend

Losartan is sold under the brand name Hyzaar.

Brand names

Hyzaar177,414

Quarterly reports (20042025)

20052010201520202025

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

Taking losartan with another medication?

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