Allopurinol adverse event reports that FDA received

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

Name type: Generic name
Class: Xanthine oxidase inhibitor
Also reported as: Allopurinol Tab, Allopurinol 100mg Tab, Allopurinol Tablets Usp

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.

Reports on file

From January 2004 to June 2026, FDA received 22,514 adverse event reports that name Allopurinol. In these reports the drug is a suspect or interacting product.

In the same period, 134,687 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 1,238 reports in the 12 months to June 2026 and 1,609 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

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 Allopurinol 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 1 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.

No update is on record for this page. The record starts when FDA adds the reports of July to September 2026.

In April to June 2026, FDA received 307 reports that name Allopurinol.
In January to March 2026, FDA received 302.
In April to June 2025, FDA received 469.

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 1,632 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 22,326 of the 22,514 reports (99.2%).

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 1,632 terms.

Reaction terms in the reports that name Allopurinol, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 22,514 reports
Drug reaction with eosinophilia and systemic symptomsDRESS, a severe reaction with rash, fever and organ involvement	3,120	13.9%
Acute kidney injurysudden loss of kidney function	1,541	6.8%
Rashskin rash	1,240	5.5%
Pyrexiafever	1,161	5.2%
Drug interactionan interaction between medicines	1,082	4.8%
Dyspnoeashortness of breath	1,059	4.7%
Toxic epidermal necrolysisa severe skin reaction with peeling	1,047	4.7%
Off label useused for a purpose or in a way not on the label	1,046	4.6%
Pruritusitching	957	4.3%
Diarrhoealoose or frequent stools	928	4.1%
Stevens-Johnson syndromea severe skin and mucous-membrane reaction	919	4.1%
Drug ineffectivethe medicine did not work as expected	903	4%
Nauseafeeling sick	860	3.8%
Anaemialow red blood cells	813	3.6%
Vomitingbeing sick	736	3.3%
Condition aggravatedthe condition being treated got worse	729	3.2%
Abdominal painstomach or belly pain	701	3.1%
Renal failurekidney failure	681	3%
Fatiguetiredness	671	3%
Hypotensionlow blood pressure	668	3%
Sepsisa severe body-wide response to infection	663	2.9%
General physical health deteriorationgeneral decline in health	661	2.9%
Rash maculo-papulara rash of flat and raised spots	624	2.8%
Eosinophilia	621	2.8%
Thrombocytopenialow platelets	612	2.7%
Multiple organ dysfunction syndromeseveral organs failing	584	2.6%
Oedema peripheralswelling of the legs, ankles or hands	576	2.6%
Erythemaskin redness	570	2.5%
Dizzinesslight-headedness or unsteadiness	568	2.5%
Astheniaweakness or lack of energy	563	2.5%
Hypertensionhigh blood pressure	556	2.5%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	555	2.5%
Renal impairmentreduced kidney function	549	2.4%
Gout	538	2.4%
Hyponatraemialow blood sodium	508	2.3%
Constipation	488	2.2%
Pancytopenialow counts of all blood cells	467	2.1%
Pneumonialung infection	449	2%
Product use in unapproved indicationused for a purpose not on the label	446	2%
Hyperkalaemiahigh blood potassium	431	1.9%
Malaisegeneral feeling of being unwell	426	1.9%
Painpain, site not specified	415	1.8%
Cardiac failureheart failure	404	1.8%
Abdominal distensiona bloated abdomen	403	1.8%
Cough	377	1.7%
Falla fall	376	1.7%
Ascitesfluid in the abdomen	375	1.7%
Blood creatinine increasedraised creatinine, a kidney test	367	1.6%
Deaththe patient died; cause not stated by this term	365	1.6%
Arthralgiajoint pain	358	1.6%

Download all 1,632 terms of Allopurinol (CSV)

The counts add to more than 22,514 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.

Outcomes by year

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

Outcomes in the reports that name Allopurinol, 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	190	180	23	31	134	8	1	52	10
2005	336	310	74	35	206	7	0	85	26
2006	186	179	34	36	131	8	0	51	7
2007	225	214	34	35	156	10	0	53	11
2008	281	265	59	39	170	7	0	72	16
2009	370	350	68	40	212	12	1	109	20
2010	459	436	62	58	267	7	1	162	23
2011	497	474	115	60	305	11	9	170	23
2012	496	459	64	33	290	8	3	203	37
2013	726	669	101	66	348	10	30	312	57
2014	687	647	93	72	370	13	1	282	40
2015	898	823	156	66	569	14	12	311	75
2016	809	717	55	58	398	19	3	424	92
2017	987	916	143	75	452	25	4	609	71
2018	1,664	1,582	168	142	941	36	6	812	82
2019	2,184	2,079	250	215	1,293	31	2	1,040	105
2020	2,012	1,948	320	194	1,170	42	8	1,084	64
2021	1,866	1,822	307	172	1,026	26	8	1,182	44
2022	1,884	1,842	282	143	1,253	41	5	1,137	42
2023	1,531	1,440	226	209	856	96	4	1,004	91
2024	1,749	1,678	235	251	989	99	16	1,105	71
2025	1,676	1,608	246	296	981	165	56	1,165	68
2026	801	767	150	136	528	92	52	508	34

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 Allopurinol, 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 Allopurinol, by the year in which FDA received them
Year	Reports
2004	162
2005	335
2006	202
2007	238
2008	282
2009	355
2010	457
2011	523
2012	594
2013	749
2014	679
2015	942
2016	852
2017	1,066
2018	1,859
2019	2,223
2020	2,091
2021	2,007
2022	1,770
2023	1,396
2024	1,695
2025	1,428
2026	609

Reports that name Allopurinol, 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 Allopurinol
Age	Reports	Share
Under 2	39	0.2%
2 to 11	110	0.5%
12 to 17	139	0.6%
18 to 44	1,781	7.9%
45 to 64	4,694	20.8%
65 to 74	4,719	21%
75 and over	6,766	30.1%
Age not given	4,266	18.9%

Sex of the patient in the reports that name Allopurinol
Sex	Reports	Share
Female	8,223	36.5%
Male	11,840	52.6%
Unknown or not given	2,451	10.9%

Type of reporter in the reports that name Allopurinol
Reporter	Reports	Share
Physician	8,408	37.3%
Pharmacist	2,493	11.1%
Other health professional	7,957	35.3%
Lawyer	27	0.1%
Consumer or non-health professional	2,580	11.5%
Not given	1,049	4.7%

Age and sex are as the report gives them. The reporter is the primary source in the report. 19.7% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Allopurinol record
Indication as recorded (MedDRA)	Reports	Share
Gout	4,230	18.8%
Hyperuricaemia	3,363	14.9%
Prophylaxis	616	2.7%
Blood uric acid increased	434	1.9%
Tumour lysis syndrome	295	1.3%
Gouty arthritis	175	0.8%

The reporter fills in the indication, and the field is often empty. Each share is of all 22,514 reports.

Drugs in the same reports

Other drugs that the reports of Allopurinol name, in any role, in order of name
Drug	Reports that name the two
Acetaminophen	1,291
Amlodipine	1,412
Aspirin	1,656
Atorvastatin	1,562
Bisoprolol	1,374
Furosemide	3,302
Omeprazole	1,364
Pantoprazole	1,539
Ramipril	1,447
Simvastatin	1,553

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.

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

Official pages

DailyMed labels for AllopurinolThe 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. Allopurinol: adverse event reports that FDA received. https://reportedreactions.com/drug/allopurinol/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of 1 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 1 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 Oct 2026. A class is the pharmacologic class (EPC) of the FDA label.

A report is in the count when it names Allopurinol as a suspect or interacting product. The 134,687 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 Allopurinol 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 Allopurinol?

No. It is a count of what people reported to FDA: 22,514 reports from January 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?

Physician (37.3%), other health professional (35.3%) and consumer or non-health professional (11.5%). 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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