Oseltamivir adverse event reports that FDA received

Name: Reaction terms in FDA adverse event reports that name Oseltamivir
Creator: Reported Reactions
License: https://creativecommons.org/publicdomain/zero/1.0/

Name type: Generic name
Class: Neuraminidase inhibitor
Also reported as: Oseltamivir 75mg, Oseltamivir 75mg Capsules

What a report is

A report is not proof that the drug was the cause of the event.

FDA says:

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.
Source: openFDA, Drug Adverse Event Overview, section "Responsible use of the data". The site read the page on 2 Oct 2026. The data have the reports that FDA received through 30 Jun 2026.

FDA also says:

There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event. The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.
Source: openFDA, Response of the drug event API (meta.disclaimer). The site read the page on 2 Oct 2026.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

Drug reports received through 30 Jun 2026. Device reports have a separate cutoff, 30 Sep 2026. Why a report count is not a rate.

Reports on file

From April 2004 to June 2026, FDA received 3,897 adverse event reports that name Oseltamivir. In these reports the drug is a suspect or interacting product.

In the same period, 2,445 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 211 reports in the 12 months to June 2026 and 666 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Of the 1,332,454 drug reports that FDA received in the 12 months to June 2026, 211 (under 0.1%) name Oseltamivir. Reports from consumers or other non-health professionals were 8.6% of the reports that name Oseltamivir and 45.8% of all drug reports.

The number of people who use the product is not in the data. A count is not a rate. A count of reports is not a count of events or of patients, because one event can have more than one report.

There are many instances of duplicative reports and some reports do not contain all the necessary information.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Suspect product

FDA records each drug in a report as suspect, concomitant or interacting. This page counts the reports in which Oseltamivir is suspect or interacting. FDA says:

Any number of the drugs may be marked as suspect if thought to be responsible for one or more of the reactions, but that information is not validated.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Data version

openFDA FAERS release of 29 Oct 2026. Reports received through 30 Jun 2026.

Since the last update

FDA says:

Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The information in these reports cannot be used to estimate the incidence (occurrence rates) of the events reported.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

The latest update of the FDA data, recorded on 28 Oct 2026, changed no count of this page.

In April to June 2026, FDA received 37 reports that name Oseltamivir.
In January to March 2026, FDA received 62.
In April to June 2025, FDA received 51.

April to June 2026 is the latest closed quarter in the data. A closed quarter is a quarter for which the FDA files have most of the reports.

All updates Feed of updates (RSS)

Reaction lookup

These are the reaction terms that the reports record, with the number of reports for each term. Type a term or a plain word to find its count.

What this list leaves out

The table lists the 328 reaction terms that 5 or more reports record. A term with fewer than 5 reports is not in the table.

The site keeps reaction terms for 3,871 of the 3,897 reports (99.3%).

The reports of the other years are not in the counts.

So a count in the table can be lower than the count of FDA.

Find a reaction term

The table shows the first 50 of 328 terms.

Reaction terms in the reports that name Oseltamivir, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 3,897 reports
Off label useused for a purpose or in a way not on the label	1,210	31%
No adverse eventno adverse event was reported	528	13.5%
Drug ineffectivethe medicine did not work as expected	385	9.9%
Foetal exposure during pregnancythe unborn baby was exposed to the medicine	197	5.1%
Condition aggravatedthe condition being treated got worse	165	4.2%
Maternal exposure during pregnancythe mother took the medicine during pregnancy	165	4.2%
Vomitingbeing sick	154	4%
Neutropenialow neutrophils, a type of white blood cell	149	3.8%
Normal newborn	143	3.7%
Product use in unapproved indicationused for a purpose not on the label	128	3.3%
Nauseafeeling sick	127	3.3%
Pneumonialung infection	109	2.8%
Bradycardiaslow heart rate	101	2.6%
Multiple organ dysfunction syndromeseveral organs failing	100	2.6%
Sepsisa severe body-wide response to infection	97	2.5%
Pathogen resistance	96	2.5%
Dyspnoeashortness of breath	94	2.4%
Exposure during pregnancythe medicine was taken during pregnancy	89	2.3%
Drug exposure during pregnancythe medicine was taken during pregnancy	86	2.2%
Premature delivery	86	2.2%
General physical health deteriorationgeneral decline in health	84	2.2%
Pyrexiafever	83	2.1%
Premature babya baby born early	76	2%
Respiratory failurethe lungs could not supply enough oxygen	76	2%
Stress	74	1.9%
Drug interactionan interaction between medicines	73	1.9%
Headachehead pain	73	1.9%
Hyponatraemialow blood sodium	73	1.9%
Abdominal painstomach or belly pain	72	1.8%
Diarrhoealoose or frequent stools	69	1.8%
Influenzaflu	65	1.7%
Anaemialow red blood cells	64	1.6%
Abdominal distensiona bloated abdomen	63	1.6%
Somnolencedrowsiness	62	1.6%
Drug ineffective for unapproved indication	61	1.6%
Pregnancy	59	1.5%
Acute respiratory distress syndrome	58	1.5%
Deaththe patient died; cause not stated by this term	58	1.5%
Intentional product misusedeliberate use not as intended	58	1.5%
Fatiguetiredness	56	1.4%
Rashskin rash	56	1.4%
Bacterial infectiona bacterial infection	55	1.4%
Sleep disordera sleep problem	54	1.4%
Ascitesfluid in the abdomen	53	1.4%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	53	1.4%
Swelling	53	1.4%
Thrombosis	53	1.4%
Asthma	52	1.3%
Pulmonary embolisma blood clot in the lung	52	1.3%
Constipation	51	1.3%

Download all 328 terms of Oseltamivir (CSV)

The counts add to more than 3,897 reports, because one report can record more than one term. FDA says:

No individual drug is connected to any individual reaction. When a report lists multiple drugs and multiple reactions, there is no way to conclude from the data therein that a given drug is responsible for a given reaction.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The CSV file has the same rows and the same limits. Its last row is a note that says so.

MedDRA term

The person who codes a report selects the preferred term that agrees best with the description of the reporter. The words under a term are the plain meaning that this site gives.

Not the label

The FDA-approved label of a product lists its adverse reactions. See the official pages at the end of this page.

Same ingredient, other names

Reporters write a brand name or a generic name. Each name has its own page and its own count.

Names of Oseltamivir with a page, in the order generic names, brand names, names as reported
Name	Name type	Reports
Oseltamivir (this page)	Generic name	3,897
Oseltamivir phosphate	Generic name	1,069
Tamiflu	Brand name	13,223

Sum of the separately reported names: 18,189. A report that names two of these names is in the sum two times. The sum is not the number of reports for the ingredient.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Outcomes by year

The table gives the outcomes that the reporters gave, in the terms of FDA.

Outcomes in the reports that name Oseltamivir, by the year of the openFDA file that holds the report

The table continues to the right.

Year of the openFDA file	Reports	Serious	Death	Life-threatening	Hospitalization (initial or prolonged)	Disability or Permanent Damage	Congenital Anomaly/Birth Defect	Other Serious (Important Medical Events)	Not serious
2004	4	3	0	0	3	0	0	1	1
2005	39	9	1	0	8	0	1	4	30
2006	24	4	0	0	0	0	1	3	20
2007	8	7	3	0	3	2	0	1	1
2008	18	15	6	2	3	0	0	7	3
2009	153	52	23	4	18	1	1	15	101
2010	109	89	25	4	32	0	0	58	20
2011	111	106	51	1	26	1	2	55	5
2012	40	39	5	2	15	0	1	19	1
2013	56	54	21	2	20	5	2	22	2
2014	25	25	6	2	13	0	0	12	0
2015	53	50	10	3	23	2	2	19	3
2016	67	52	19	5	29	0	0	27	15
2017	73	51	8	10	27	3	0	30	22
2018	171	139	41	17	37	1	0	88	32
2019	247	206	24	6	48	4	70	127	41
2020	563	467	74	37	155	5	1	346	96
2021	618	499	70	19	121	0	0	401	119
2022	237	198	48	17	96	4	5	125	39
2023	263	248	38	30	81	14	0	192	15
2024	608	157	24	29	75	7	2	103	451
2025	284	254	51	54	127	23	17	167	30
2026	126	112	42	40	81	31	26	75	14

An outcome in a report is not proof that the drug was the cause. The reporter gives the outcome, and FDA does not verify it. FDA says:

The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

The six headings with the names of FDA are the outcome terms of FDA. A report can have more than one outcome. The columns Serious and Not serious are the two values of the openFDA field serious. For the value serious, openFDA gives this description:

The adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition
Source: openFDA, Drug adverse event fields (YAML reference). The site read the page on 2 Oct 2026.

The year is the year of the openFDA file that holds the latest version of the report. It is not always the year in which FDA first received the report. The chart of the next section uses the year of first receipt. The latest year is not complete.

Reports by year and month

Reports that name Oseltamivir, by the year in which FDA received them

The column of 2026 has an outline, because the year is not complete. It has the reports that FDA received through June 2026 only.

Show the figures of the chart as a table

Reports that name Oseltamivir, by the year in which FDA received them
Year	Reports
2004	3
2005	7
2006	4
2007	7
2008	15
2009	211
2010	112
2011	122
2012	48
2013	44
2014	23
2015	52
2016	68
2017	83
2018	178
2019	252
2020	592
2021	630
2022	344
2023	135
2024	606
2025	262
2026	99

Reports that name Oseltamivir, by month, five years to June 2026

FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Why a count moves

A count moves for many reasons. The guide gives FDA's words about them.

Patients and reporters

Age of the patient in the reports that name Oseltamivir
Age	Reports	Share
Under 2	70	1.8%
2 to 11	248	6.4%
12 to 17	123	3.2%
18 to 44	828	21.2%
45 to 64	526	13.5%
65 to 74	273	7%
75 and over	327	8.4%
Age not given	1,502	38.5%

Sex of the patient in the reports that name Oseltamivir
Sex	Reports	Share
Female	1,543	39.6%
Male	1,565	40.2%
Unknown or not given	789	20.2%

Type of reporter in the reports that name Oseltamivir
Reporter	Reports	Share
Physician	1,146	29.4%
Pharmacist	264	6.8%
Other health professional	2,061	52.9%
Lawyer	1	under 0.1%
Consumer or non-health professional	334	8.6%
Not given	91	2.3%

Age and sex are as the report gives them. The reporter is the primary source in the report. 29% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Oseltamivir record
Indication as recorded (MedDRA)	Reports	Share
Influenza	1,138	29.2%
Covid-19	1,003	25.7%
H1n1 influenza	163	4.2%
Covid-19 pneumonia	83	2.1%
Pneumonia	51	1.3%
Avian influenza	49	1.3%

The reporter fills in the indication, and the field is often empty. Each share is of all 3,897 reports.

Drugs in the same reports

Other drugs that the reports of Oseltamivir name, in any role, in order of name
Drug	Reports that name the two
Acetaminophen	181
Azithromycin	196
Azithromycin Anhydrous	412
Ceftriaxone	387
Hydroxychloroquine	435
Levofloxacin	126
Meropenem	264
Methylprednisolone	191
Prednisone	101
Vancomycin	204

The table has the 10 drug names that these reports name most. Two names in one report says only that the report recorded the two. It says nothing about the part of a product in the event.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

Pages near this one

Oseltamivir phosphate same ingredient
Tamiflu same ingredient
Relenza same class
Ortho Tri-Cyclen Lo next in the A to Z list
Ortho Tri-Cyclen next in the A to Z list
Osimertinib next in the A to Z list
Ortho Tri Cyclen Lo next in the A to Z list
Osimertinib mesylate next in the A to Z list
Ortho Tri Cyclen next in the A to Z list
Osmolex Er next in the A to Z list
Ortho Evra next in the A to Z list
Osmoprep next in the A to Z list

These links are for navigation. No count selected them. The class page lists each drug of the class.

Official pages

DailyMed labels for OseltamivirThe labels (prescribing information) that have this name, at the National Library of Medicine.
MedWatch Online Voluntary Reporting FormThe online form of FDA for a voluntary report.
MedWatch: The FDA Safety Information and Adverse Event Reporting ProgramThe page of the FDA program that receives reports about drugs and devices.
FDA Adverse Event Monitoring System (AEMS) Public DashboardThe public dashboard of FDA for adverse event reports on drugs and biologics.

The site checked these addresses on 2 Oct 2026. The links open in a new tab.

Cite this page

Reported Reactions. Oseltamivir: adverse event reports that FDA received. https://reportedreactions.com/drug/oseltamivir/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of 29 Oct 2026. Reports received through 30 Jun 2026.

Where the data come from

The counts come from the openFDA Drug Adverse Event (FAERS) bulk files, release of 29 Oct 2026. The files have the reports that FDA received through 30 Jun 2026. A drug name is the name on the report. The site matches it to a brand name or a generic name of the National Drug Code Directory of 2 Nov 2026. A class is the pharmacologic class (EPC) of the FDA label.

A report is in the count when it names Oseltamivir as a suspect or interacting product. The 2,445 reports that name it only as a concomitant medicine are not in the count. The site does not publish a report narrative, a lot number, a detail of a patient or the identity of a reporter. The record of FDA is the authority. See how the site counts reports, the data sources and the corrections page.

Questions

Do these reports show that Oseltamivir was responsible for the reactions?

No. FDA says:

For any given report, there is no certainty that a suspected drug caused the event.
Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of 11 Mar 2026. The site read the page on 2 Oct 2026.

A reaction can relate to the condition that the drug treats, to other medicines, or to something else.

Is this the list of reactions on the label of Oseltamivir?

No. It is a count of what people reported to FDA: 3,897 reports from April 2004 to June 2026. The FDA-approved label of a product lists its adverse reactions. The official pages at the end of this page link to the labels.

Who sent these reports?

Other health professional (52.9%), physician (29.4%) and consumer or non-health professional (8.6%). These are the types of reporter for the reports that name this drug.

If a manufacturer receives an adverse event report, it is normally required to send the report to FDA.
Source: openFDA, Drug Adverse Event Overview. The site read the page on 2 Oct 2026.

How does a person report an adverse event?

FDA runs MedWatch, a program that takes voluntary reports from health professionals, patients and consumers. The guide on how to report has the links.

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