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Oseltamivir Side Effects

The most commonly reported side effects of oseltamivir include off label use, vomiting, and nausea, based on 24,032 FDA adverse event reports from 2004 to 2025. 4.5% of reports found the drug to be ineffective.

Oseltamivir side effects

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

1
Off Label Use8.6%2,056
2
Vomiting7.4%1,788
3
Nausea5.8%1,386
4
Drug Ineffective4.5%1,077
5
Influenza4.3%1,036
6
Diarrhoea3.7%884
7
No Adverse Event3.7%884
8
Dyspnoea3.7%883
9
Headache3.4%828
10
Pyrexia3.1%734
11
Pneumonia3.0%709
12
No Adverse Event2.9%699
13
Rash2.7%639
14
Drug Exposure During Pregnancy2.5%609
15
Cough2.5%597

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

Report severity

65.3%Serious15,690 reports
26.6%Hospitalizations6,402 reports
11.0%Fatal2,651 reports

Seriousness is determined by the reporter, not by OpenClaim.

Oseltamivir drug interactions

Other drugs that appear in adverse event reports alongside oseltamivir. 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
Azithromycin4.7%1,124
2
Ceftriaxone-sodium4.1%984
3
Albuterol2.9%708
4
Acetaminophen2.9%692
5
Prednisone2.8%680
6
Lansoprazole2.6%627
7
Hydroxychloroquine-sulfate2.5%605
8
Dexamethasone2.2%535
9
Lenalidomide2.1%511
10
Esomeprazole2.0%469
11
Hydromorphone-hydrochloride1.9%465
12
Amoxicillin1.9%461
13
Omeprazole1.8%444
14
Ciprofloxacin1.6%385
15
Vancomycin1.6%375

Taken alongside

1
Acetaminophen10.1%2,422
2
Albuterol6.7%1,610
3
Azithromycin6.0%1,433
4
Prednisone5.5%1,315
5
Aspirin4.8%1,146
6
Fluticasone4.7%1,141
7
Ibuprofen4.6%1,103
8
Ergocalciferol4.6%1,094
9
Amoxicillin4.5%1,087
10
Furosemide4.4%1,057
11
Ondansetron4.1%997
12
Omeprazole4.0%952
13
Levothyroxine-sodium3.7%883
14
Pantoprazole-sodium3.6%876
15
Levofloxacin3.5%847

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 oseltamivir side effects

49.3% of oseltamivir adverse event reports involve female patients and 38.5% involve male patients. The largest age group is adult at 50%. These figures reflect who reports side effects, not underlying risk.

Sex

Female49.3%
Male38.5%
Unknown12.2%

Age group

< 24.4%
2–1116.6%
12–176.2%
18–6450.3%
65+22.5%

What is oseltamivir used for

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

Abnormal Withdrawal BleedingAcute Respiratory Distress SyndromeAcute Respiratory FailureAdenovirus InfectionAdverse EventAllergy ProphylaxisAnti-infective TherapyAntibiotic ProphylaxisAntibiotic TherapyAnticoagulant TherapyAntiviral ProphylaxisAntiviral TreatmentArthralgiaAstheniaAsthma

Showing 15 of 379 indications

Oseltamivir brand names and reporting trend

Oseltamivir is sold under the brand name Tamiflu.

Brand names

Tamiflu8,805

Quarterly reports (20042025)

20052010201520202025

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

Taking oseltamivir with another medication?

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