Pirfenidone adverse event reports that FDA received

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

Name type: Generic name
Class: Pyridone

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 2009 to June 2026, FDA received 3,519 adverse event reports that name Pirfenidone. In these reports the drug is a suspect or interacting product.

In the same period, 836 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 709 reports in the 12 months to June 2026 and 628 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, 709 (0.1%) name Pirfenidone. Reports for male patients were 62.8% of the reports that name Pirfenidone and 34.6% 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 Pirfenidone 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 242 reports that name Pirfenidone.
In January to March 2026, FDA received 138.
In April to June 2025, FDA received 150.

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 258 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 3,501 of the 3,519 reports (99.5%).

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 258 terms.

Reaction terms in the reports that name Pirfenidone, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 3,519 reports
Deaththe patient died; cause not stated by this term	667	19%
Nauseafeeling sick	272	7.7%
Dyspnoeashortness of breath	241	6.8%
Decreased appetitereduced appetite	208	5.9%
Pneumonialung infection	200	5.7%
Diarrhoealoose or frequent stools	195	5.5%
Fatiguetiredness	181	5.1%
Weight decreasedweight loss	159	4.5%
Cough	140	4%
Idiopathic pulmonary fibrosis	138	3.9%
Rashskin rash	128	3.6%
Dizzinesslight-headedness or unsteadiness	120	3.4%
Interstitial lung diseasescarring or inflammation of lung tissue	107	3%
Astheniaweakness or lack of energy	106	3%
Vomitingbeing sick	103	2.9%
Photosensitivity reactionskin reaction to sunlight	94	2.7%
Cerebrovascular accidentstroke	85	2.4%
Headachehead pain	84	2.4%
Malaisegeneral feeling of being unwell	84	2.4%
Abdominal discomfortstomach discomfort	78	2.2%
Pruritusitching	78	2.2%
Oxygen saturation decreased	72	2%
Condition aggravatedthe condition being treated got worse	71	2%
Abdominal pain upperupper stomach pain	70	2%
Gastrointestinal disorder	70	2%
Disease progressionthe disease advanced	68	1.9%
Lower respiratory tract infectiona chest infection	68	1.9%
Hospitalisationadmission to hospital	66	1.9%
Therapy interrupted	63	1.8%
Dyspepsiaindigestion	62	1.8%
Drug ineffectivethe medicine did not work as expected	60	1.7%
Respiratory failurethe lungs could not supply enough oxygen	58	1.6%
Off label useused for a purpose or in a way not on the label	57	1.6%
Pulmonary fibrosis	56	1.6%
Insomniadifficulty sleeping	55	1.6%
Hospice care	54	1.5%
Forced vital capacity decreased	53	1.5%
Therapy cessation	53	1.5%
Acute respiratory failure	52	1.5%
Constipation	49	1.4%
Drug intolerancethe medicine was not tolerated	49	1.4%
Hypotensionlow blood pressure	49	1.4%
Abdominal painstomach or belly pain	42	1.2%
Sepsisa severe body-wide response to infection	42	1.2%
Falla fall	41	1.2%
Pulmonary function test decreased	41	1.2%
Gastrooesophageal reflux diseaseacid reflux	39	1.1%
Drug interactionan interaction between medicines	38	1.1%
General physical health deteriorationgeneral decline in health	38	1.1%
Myalgiamuscle pain	38	1.1%

Download all 258 terms of Pirfenidone (CSV)

The counts add to more than 3,519 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 Pirfenidone with a page, in the order generic names, brand names, names as reported
Name	Name type	Reports
Pirfenidone (this page)	Generic name	3,519
Esbriet	Brand name	35,230

Sum of the separately reported names: 38,749. 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 Pirfenidone, 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
2009	5	5	4	1	1	0	0	2	0
2010	14	14	7	0	8	0	0	5	0
2011	4	4	2	0	4	0	0	1	0
2012	6	6	3	0	4	0	0	3	0
2013	3	3	1	0	2	0	0	2	0
2014	13	11	4	1	5	0	0	4	2
2015	125	112	33	6	38	4	0	49	13
2016	90	69	17	5	27	4	0	32	21
2017	88	80	21	0	34	1	0	41	8
2018	85	82	19	1	27	1	0	54	3
2019	110	100	17	9	51	0	0	55	10
2020	95	88	16	4	31	1	0	51	7
2021	70	62	9	1	23	0	0	41	8
2022	312	253	82	8	113	1	1	84	59
2023	734	677	226	15	270	4	2	254	57
2024	694	579	243	20	158	5	0	245	115
2025	651	529	257	33	146	0	0	227	122
2026	420	360	86	6	122	0	0	189	60

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 Pirfenidone, 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 Pirfenidone, by the year in which FDA received them
Year	Reports
2009	5
2010	14
2011	4
2012	7
2013	2
2014	14
2015	149
2016	92
2017	85
2018	101
2019	120
2020	97
2021	62
2022	320
2023	709
2024	718
2025	640
2026	380

Reports that name Pirfenidone, 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 Pirfenidone
Age	Reports	Share
Under 2	5	0.1%
2 to 11	3	0.1%
12 to 17	2	0.1%
18 to 44	34	1%
45 to 64	280	8%
65 to 74	846	24%
75 and over	1,223	34.8%
Age not given	1,126	32%

Sex of the patient in the reports that name Pirfenidone
Sex	Reports	Share
Female	935	26.6%
Male	2,209	62.8%
Unknown or not given	375	10.7%

Type of reporter in the reports that name Pirfenidone
Reporter	Reports	Share
Physician	810	23%
Pharmacist	419	11.9%
Other health professional	1,388	39.4%
Lawyer	0	0%
Consumer or non-health professional	632	18%
Not given	270	7.7%

Age and sex are as the report gives them. The reporter is the primary source in the report. 50% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Pirfenidone record
Indication as recorded (MedDRA)	Reports	Share
Idiopathic pulmonary fibrosis	1,480	42.1%
Pulmonary fibrosis	354	10.1%
Interstitial lung disease	327	9.3%
Non-small cell lung cancer	19	0.5%
Bronchiolitis obliterans syndrome	15	0.4%
Hypersensitivity pneumonitis	8	0.2%

The reporter fills in the indication, and the field is often empty. Each share is of all 3,519 reports.

Drugs in the same reports

Other drugs that the reports of Pirfenidone name, in any role, in order of name
Drug	Reports that name the two
Aspirin	149
Atorvastatin	108
Esbriet	79
Furosemide	83
Nintedanib	129
Ofev	97
Omeprazole	116
Oxygen	87
Pantoprazole	82
Prednisone	122

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

Esbriet same ingredient
Pirarubicin Hydrochloride next in the A to Z list
Piritramide next in the A to Z list
Pirarubicin next in the A to Z list
Piroxicam next in the A to Z list
Piracetam next in the A to Z list
Pirtobrutinib next in the A to Z list
Piqray next in the A to Z list
Pitavastatin next in the A to Z list
Piperacillin sodium,tazobactam sodium next in the A to Z list
Pitavastatin calcium next in the A to Z list
Piperacillin Sodium 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 PirfenidoneThe 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. Pirfenidone: adverse event reports that FDA received. https://reportedreactions.com/drug/pirfenidone/ 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 Pirfenidone as a suspect or interacting product. The 836 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 Pirfenidone 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 Pirfenidone?

No. It is a count of what people reported to FDA: 3,519 reports from April 2009 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 (39.4%), physician (23%) and consumer or non-health professional (18%). 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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