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Omeprazole Side Effects

The most commonly reported side effects of omeprazole include chronic kidney disease, acute kidney injury, and fatigue, based on 498,510 FDA adverse event reports from 2004 to 2025. 4.4% of reports found the drug to be ineffective.

Omeprazole side effects

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

1
Chronic Kidney Disease7.5%37,448
2
Acute Kidney Injury5.2%26,068
3
Fatigue5.2%25,674
4
Nausea5.1%25,351
5
Diarrhoea5.0%25,122
6
Drug Ineffective4.4%21,847
7
Dyspnoea3.9%19,573
8
Pain3.8%19,160
9
Headache3.8%19,044
10
Off Label Use3.6%18,027
11
Renal Failure3.5%17,647
12
Vomiting3.2%15,996
13
Dizziness3.1%15,667
14
Malaise2.8%13,930
15
Arthralgia2.7%13,660

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

Report severity

73.4%Serious366,032 reports
35.1%Hospitalizations175,107 reports
8.9%Fatal44,519 reports

Seriousness is determined by the reporter, not by OpenClaim.

Omeprazole drug interactions

Other drugs that appear in adverse event reports alongside omeprazole. 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
Esomeprazole8.4%42,010
2
Lansoprazole7.1%35,562
3
Pantoprazole-sodium6.6%32,681
4
Adalimumab4.3%21,352
5
Lenalidomide4.2%21,158
6
Dexlansoprazole3.8%18,816
7
Naproxen1.6%8,019
8
Etanercept1.6%7,904
9
Acetaminophen1.5%7,524
10
Sodium-oxybate1.5%7,362
11
Prednisone1.4%6,935
12
Dupilumab1.4%6,802
13
Rabeprazole-sodium1.4%6,767
14
Dexamethasone1.3%6,707
15
Aspirin1.3%6,628

Taken alongside

1
Acetaminophen17.8%88,663
2
Aspirin17.4%86,592
3
Ergocalciferol12.8%63,764
4
Levothyroxine-sodium12.5%62,410
5
Atorvastatin-calcium12.2%60,696
6
Furosemide11.9%59,074
7
Albuterol10.9%54,454
8
Amlodipine10.6%52,738
9
Gabapentin9.8%48,832
10
Metoprolol9.5%47,146
11
Lisinopril9.0%45,091
12
Metformin8.7%43,266
13
Prednisone8.6%42,812
14
Simvastatin7.9%39,530
15
Fluticasone7.7%38,443

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 omeprazole side effects

54.2% of omeprazole adverse event reports involve female patients and 36.2% involve male patients. The largest age group is adult at 50%. These figures reflect who reports side effects, not underlying risk.

Sex

Female54.2%
Male36.2%
Unknown9.6%

Age group

< 20.6%
2–110.9%
12–171.2%
18–6450.1%
65+47.2%

What is omeprazole used for

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

AbasiaAbdominal AdhesionsAbdominal DiscomfortAbdominal DistensionAbdominal HerniaAbdominal InfectionAbdominal InjuryAbdominal MigraineAbdominal OperationAbdominal PainAbdominal Pain LowerAbdominal Pain UpperAbdominal RigidityAbdominal SymptomAbdominal Tenderness

Showing 15 of 2,052 indications

Omeprazole brand names and reporting trend

Omeprazole is sold under brand names including Konvomep, Prilosec Otc.

Brand names

Konvomep425,534
Prilosec Otc6,892

Quarterly reports (20042025)

20052010201520202025

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

Taking omeprazole with another medication?

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