Prescription medication · Neuraminidase Inhibitor (Antiviral)
oseltamivir
Also sold as Tamiflu. This medicine treats the flu in people 2 weeks and older who have had symptoms for no more than 48 hours.
Data updated 2026-05-15
- 7,575
- FDA reportsLightly reported
- 5
- InteractionsFew interactions
- 99% less
- Generic vs brandHuge savings
- In shortage
- FDA status
What the data shows
oseltamivir (Tamiflu) is a prescription Neuraminidase Inhibitor (Antiviral), reported less often than most tracked drugs (7,575 FDA reports), whose generic costs a fraction of the brand (about 99% less).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
oseltamivir (Tamiflu) is a prescription Neuraminidase Inhibitor (Antiviral). This medicine treats the flu in people 2 weeks and older who have had symptoms for no more than 48 hours.
Oseltamivir (Tamiflu) is an antiviral medicine. It helps treat and prevent the flu (influenza A and B).
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
oseltamivir is currently listed as to be discontinued by the FDA. Affected manufacturer: Genentech, Inc.
View all drug shortages →Drug Pricing (NADAC)
Brand Price
$14.62/unit
Generic Price
$0.18/unit
Generic Savings
99%
Generic Available
Yes (30 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine treats the flu in people 2 weeks and older who have had symptoms for no more than 48 hours.
Common side effects
Nausea, Vomiting, Headache
Key warnings
Rarely, this medicine has been linked to serious skin reactions and allergic reactions.
The sections below are summarized in plain English from oseltamivir's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Oseltamivir stops the flu virus from spreading in your body. It does this by blocking a protein on the virus called neuraminidase. This helps you get better faster or prevents you from getting sick.
Side Effects (from patient reports)
Based on 7,575 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for oseltamivir, by number of reports
- Vomiting
Vomiting
444 reports
- Nausea
Nausea
443 reports
- Headache
Headache
381 reports
- Pneumonia
Pneumonia
368 reports
- Condition Aggravated
Condition Aggravated
332 reports
- Influenza
Influenza
330 reports
- Dyspnoea
Dyspnoea
283 reports
- Abdominal Pain
Abdominal Pain
280 reports
- Sepsis
Sepsis
260 reports
- Diarrhoea
Diarrhoea
259 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for oseltamivir each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where oseltamivir sits
oseltamivir has more FDA adverse-event reports than 34% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is oseltamivir; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 7,575 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
7,575
Reports Mentioning Death
1,149
15.2% of reports — not proof of cause
Hospitalization Reports
2,529
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 4 | VOMITING | 444 |
| 5 | NAUSEA | 443 |
| 6 | HEADACHE | 381 |
| 7 | PNEUMONIA | 368 |
| 8 | CONDITION AGGRAVATED | 332 |
| 9 | INFLUENZA | 330 |
| 12 | DYSPNOEA | 283 |
| 13 | ABDOMINAL PAIN | 280 |
| 14 | SEPSIS | 260 |
| 15 | DIARRHOEA | 259 |
| 16 | DRUG INEFFECTIVE FOR UNAPPROVED INDICATION | 254 |
| 17 | PYREXIA | 250 |
| 18 | MULTIPLE ORGAN DYSFUNCTION SYNDROME | 246 |
| 19 | HYPERSENSITIVITY | 243 |
| 20 | GENERAL PHYSICAL HEALTH DETERIORATION | 226 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Rarely, this medicine has been linked to serious skin reactions and allergic reactions. Stop taking this medicine and get medical help right away if you have signs of an allergic reaction or a severe skin rash. Some people, especially children, may experience confusion or unusual behavior while taking this medicine. Watch for any changes in behavior and tell your doctor right away.
Known Drug Interactions
7.2 Drugs Without Clinically Significant Drug Interaction with Oseltamivir Phosphate for Oral Suspension No dose adjustments are needed for either oseltamivir or the concomitant drug when coadministering oseltamivir with amoxicillin, acetaminophen, aspirin, cimetidine, antacids (magnesium and aluminum hydroxides and calcium carbonates), rimantadine, amantadine, or warfarin [see Clinical Pharmacology (12.3) ] .
Mechanism: These two drugs do not have a meaningful impact on how the body processes or uses either medication.
7.2 Drugs Without Clinically Significant Drug Interaction with Oseltamivir Phosphate for Oral Suspension No dose adjustments are needed for either oseltamivir or the concomitant drug when coadministering oseltamivir with amoxicillin, acetaminophen, aspirin, cimetidine, antacids (magnesium and aluminum hydroxides and calcium carbonates), rimantadine, amantadine, or warfarin [see Clinical Pharmacology (12.3) ] .
Mechanism: There is no significant interaction between these drugs that would change how they work in your body.
7.2 Drugs Without Clinically Significant Drug Interaction with Oseltamivir Phosphate for Oral Suspension No dose adjustments are needed for either oseltamivir or the concomitant drug when coadministering oseltamivir with amoxicillin, acetaminophen, aspirin, cimetidine, antacids (magnesium and aluminum hydroxides and calcium carbonates), rimantadine, amantadine, or warfarin [see Clinical Pharmacology (12.3) ] .
Mechanism: These medications do not interfere with each other's levels or effectiveness in the body.
7.2 Drugs Without Clinically Significant Drug Interaction with Oseltamivir Phosphate for Oral Suspension No dose adjustments are needed for either oseltamivir or the concomitant drug when coadministering oseltamivir with amoxicillin, acetaminophen, aspirin, cimetidine, antacids (magnesium and aluminum hydroxides and calcium carbonates), rimantadine, amantadine, or warfarin [see Clinical Pharmacology (12.3) ] .
Mechanism: These drugs do not change how the body handles or clears either medicine from your system.
7.2 Drugs Without Clinically Significant Drug Interaction with Oseltamivir Phosphate for Oral Suspension No dose adjustments are needed for either oseltamivir or the concomitant drug when coadministering oseltamivir with amoxicillin, acetaminophen, aspirin, cimetidine, antacids (magnesium and aluminum hydroxides and calcium carbonates), rimantadine, amantadine, or warfarin [see Clinical Pharmacology (12.3) ] .
Mechanism: These drugs do not interfere with each other's absorption or removal from the body.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
Can I get a flu shot while taking this medicine?
What should I do if I have kidney problems?
Can I take this medicine with other medicines?
What if I am allergic to one of the ingredients?
How long should I take this medicine?
What if my symptoms get worse?
Can this medicine prevent bacterial infections?
Is this medicine safe for children?
What does 'prophylaxis' mean?
Can I use the constituted suspension after 20 days if refrigerated?
What are the common side effects of oseltamivir?
Does oseltamivir interact with other medications?
What drug class is oseltamivir?
Is there a generic version of oseltamivir?
What pregnancy or breastfeeding source fields are listed for oseltamivir?
Is oseltamivir currently in shortage?
Related Medications in Neuraminidase Inhibitor (Antiviral)
Other drugs grouped near oseltamivir - same-class peers and common alternatives.
acyclovir
Zovirax
Acyclovir is an antiviral medicine.
Compare with oseltamivir →
albendazole
Albenza
Albendazole is a medicine that fights parasites.
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amphotericin B
Ambisome, Fungizone
Amphotericin B liposome is an antifungal medicine.
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anidulafungin
Eraxis
Eraxis is an antifungal medicine.
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atovaquone/proguanil
Malarone
Malarone is a drug used to prevent and treat malaria.
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Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for oseltamivir: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 7,575.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 15.17%.
- sildenafil Δ 0.00 pts · 55,325 reports · PDE5 Inhibitor 15.17%death share
- memantine Δ 0.07 pts · 12,807 reports · NMDA Receptor Antagonist 15.10%death share
- entacapone Δ 0.08 pts · 3,955 reports · COMT Inhibitor 15.25%death share
- senna Δ 0.17 pts · 20,197 reports · Stimulant Laxative 15.34%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for oseltamivir
The FDA label for oseltamivir (sold under brand names such as Tamiflu) classifies it as a prescription-only medication in the Neuraminidase Inhibitor (Antiviral) class. This medicine treats the flu in people 2 weeks and older who have had symptoms for no more than 48 hours. Official labeling lists 4 commonly reported side effects, including Nausea, Vomiting, Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 7,575 voluntary reports. The database also lists 5 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.18 versus $14.62 for the brand - a 99% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: May 15, 2024
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages