Pharmacologic class (EPC) · 4 drug pages

Neuraminidase inhibitor: adverse event reports filed with FDA

20,262 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

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. openFDA, FDA

FDA adds: "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 "cannot be used to estimate the incidence of these events."

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.

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

20,262
reports across the class: 0.1% of all reports; 521
reports, 12 months to June 2026: 1,803 in the 12 months before; 60.6%
marked serious by the reporter: 57.4% across all reports; 4
drugs with a page: brand and generic names counted separately

Neuraminidase inhibitor is a pharmacologic class (an FDA Established Pharmacologic Class) with 4 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 20,262 adverse event reports received by FDA, 0.1% of the database, from January 2004 to June 2026.

521 reports arrived in the 12 months to June 2026, down 71% from 1,803 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 60.6% of the class's reports are marked serious, 10.2% record death among the outcomes and 20% record hospitalisation, as reported.

Across the class the reactions recorded most often are vomiting (9.6%), no adverse event (8.2%) and off label use (8.1%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
TamifluOseltamivir phosphate	brand	13,223	190	57.2%	Vomiting
Oseltamivir	generic	3,897	211	72.8%	Off label use
RelenzaZanamivir	brand	2,073	0	56.4%	Overdose
Oseltamivir phosphate	generic	1,069	120	66.9%	Vomiting

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Vomitingbeing sick9.6%1,937
No adverse eventno adverse event was reported8.2%1,670
Off label useused for a purpose or in a way not on the label8.1%1,633
Abnormal behaviourunusual behaviour6.5%1,320
Nauseafeeling sick6.4%1,295
Hallucinationseeing or hearing things that are not there4.7%960
Drug ineffectivethe medicine did not work as expected4.6%939
Drug exposure during pregnancythe medicine was taken during pregnancy4.1%832
Dyspnoeashortness of breath3.9%781
Diarrhoealoose or frequent stools3.5%709
Overdosea dose above the recommended amount3.4%687
Pyrexiafever3.1%627
Influenzaflu2.8%567
Rashskin rash2.7%542
Abdominal painstomach or belly pain2.5%503
Headachehead pain2.5%501
Deaththe patient died; cause not stated by this term2.4%477
Pneumonialung infection2.3%474
Coughcough2.3%473
Urticariahives2.2%444
Deliriumsudden confusion2.1%419
Dizzinesslight-headedness or unsteadiness2.1%416
Condition aggravatedthe condition being treated got worse2%413
Confusional stateconfusion1.8%373
Insomniadifficulty sleeping1.8%373

Solid bar: share of all class reports. Hollow bar: the median share across the 4 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death10.2%2,071

Life-threatening5%1,008

Hospitalisation (initial or prolonged)20%4,059

Disability2.8%559

Congenital anomaly1.2%252

Other serious38%7,703

Not serious39.4%7,983

Patient age

Under 22.3%469

2 to 1114.1%2,862

12 to 175.7%1,161

18 to 4416.6%3,362

45 to 6411.8%2,397

65 to 745.2%1,053

75 and over7.4%1,498

Age not given36.8%7,460

Who reported

Physician28.7%5,810

Pharmacist14.7%2,986

Other health professional20.9%4,225

Lawyer0.1%23

Consumer or non-health professional32.8%6,636

Not given2.9%582

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Neuraminidase inhibitor reports

Which drugs are in the Neuraminidase inhibitor class on this site?

Tamiflu, Oseltamivir, Relenza and Oseltamivir phosphate. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

20,262 reports through June 2026, 521 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

vomiting (9.6%), no adverse event (8.2%), off label use (8.1%), abnormal behaviour (6.5%) and nausea (6.4%).

Can the members table be used to rank the drugs?

No. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.