TAMIFLU FDA MedWatch Voluntary U.S. Reports Summary

These tables and charts are created from 888 U.S. reports for TAMIFLU (OSELTAMIVIR PHOSPHATE) voluntarily reported by individuals directly to the FDA via the MedWatch Reporting System from 2004 through July 30, 2026. Events listed on this page represent serious and often rare adverse events reported to the FDA, and often do not represent typical side effects for the medication. Find common side effects on the most recent official drug label.

For a summary of adverse events including mandatory reports submitted by pharmaceutical companies (all countries and all reporter types) to the FAERS database, View FDA FAERS TAMIFLU Report.

Top Adverse Events Reported with TAMIFLU (from U.S. FDA Medwatch Reports)

 Side Effect# of FDA Reports
1HALLUCINATION136
2VOMITING103
3ABNORMAL BEHAVIOUR79
4NAUSEA74
5CONFUSIONAL STATE70
6INSOMNIA58
7DIARRHEA53
8DIZZINESS45
9ANXIETY44
10NIGHTMARE44
11SCREAMING44
12RASH43
13CRYING42
14FEAR39
15FEELING ABNORMAL39
16ABDOMINAL PAIN UPPER35
17SHORTNESS OF BREATH34
18HEADACHE34
19AGGRESSION32
20INFLUENZA29
21DELIRIUM27
22SLEEP TERROR27
23PAIN26
24FEVER26
25HIVES26
Search all MedWatch Reports by Keyword:

TAMIFLU Total Medwatch Safety Reports by Patient Sex

 Male    Female    Unknown    Total  
 377    471    40    888  

Medwatch Reporter TypeCount
Consumer392
Physician31
Pharmacist90
Other Health Professional66
Lawyer1

Top Indications      
Product used for unknown indication
Influenza
Pneumonia
Influenza A virus test positive
Infection

Type of Outcome Reported
Serious: 607
Not Serious: 281
Note: A serious outcome means the adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition.

Suspected Role
Primary Suspect: 887
Concomitant Drugs: 390
Note: A single MedWatch report can list more than one drug. This summary includes TAMIFLU identified as the suspect drug or as a concomitantly taken drug.

FDA Safety-Related Labeling Changes

TAMIFLU (OSELTAMIVIR PHOSPHATE) Rx Drug:
FDA Safety-related Labeling Changes


Have experience (good or bad) with TAMIFLU? Rate TAMIFLU at Ask a Patient.

For serious adverse events, report them to the FDA by contacting the drug manufacturer or report directly through the MedWatch voluntary reporting form.

NOTES

This report, created by AskaPatient.com, is derived from U.S. drug-related adverse event cases that were reported directly to the FDA using the voluntary MedWatch online or paper reporting system. MedWatch is the voluntary FDA system for consumers, physicians, and others to directly report adverse reactions. The Medwatch initiative was launched in 1993 as a voluntary reporting program for consumers, physicians and other healthcare practitioners.

After processing the received forms, the FDA adds the MedWatch reports to the FDA Adverse Events Reporting System(or FAERS database.) Click here for the complete FAERS report summary, which includes mandatory reports submitted by pharmaceutical companies (worldwide) combined with the MedWatch reports. MedWatch Reports only represent about 5% of the FAERS database. For more, read "Does the FDA's Rapidly Growing Database of Adverse Events Improve Drug Safety?"


The data in this report was obtained from Open FDA. Data was last updated to include reports through January 27, 2026. The reactions, side effects, or "adverse events," represent up to the 20 most frequently occuring events in the database for a drug related to the event. 

Open FDA states that it only includes the most recent version of a case report. It also adds the disclaimer: "Do not rely on Open FDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated."

FDA uses the "MedDRA" classification system to describe reported adverse reactions. MedDRA is a standardized medical terminology that facilitates sharing of regulatory information internationally. In some cases, "patient friendly" terms for the layman designated by MedDRA have been substituted for medical jargon. Please contact us with questions about this report.