Sulfamethoxazole adverse event reports that FDA received

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

Name type: Generic name
Also reported as: Sulfamethoxazole 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 4,866 adverse event reports that name Sulfamethoxazole. In these reports the drug is a suspect or interacting product.

In the same period, 7,105 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 664 reports in the 12 months to June 2026 and 864 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 Sulfamethoxazole 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 171 reports that name Sulfamethoxazole.
In January to March 2026, FDA received 114.
In April to June 2025, FDA received 152.

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 556 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 4,833 of the 4,866 reports (99.3%).

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 556 terms.

Reaction terms in the reports that name Sulfamethoxazole, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 4,866 reports
Rashskin rash	2,339	48.1%
Fatiguetiredness	2,273	46.7%
Pyrexiafever	2,242	46.1%
Joint swellinga swollen joint	2,218	45.6%
Infectionan infection, type not specified	2,196	45.1%
Dyspnoeashortness of breath	2,180	44.8%
Folliculitis	2,161	44.4%
Impaired healingslow healing	2,160	44.4%
Swelling	2,156	44.3%
Hypersensitivityan allergic-type reaction	2,136	43.9%
Stomatitissore mouth	2,120	43.6%
Infusion related reactiona reaction during or soon after an infusion	2,116	43.5%
Weight increasedweight gain	2,104	43.2%
Pruritusitching	2,100	43.2%
Synovitis	2,089	42.9%
Sinusitissinus infection	2,078	42.7%
Irritable bowel syndrome	2,064	42.4%
Painpain, site not specified	2,058	42.3%
Peripheral swellingswelling of the arms or legs	2,053	42.2%
Gastrointestinal disorder	2,030	41.7%
Confusional stateconfusion	2,021	41.5%
Arthralgiajoint pain	2,017	41.5%
Lower respiratory tract infectiona chest infection	2,015	41.4%
Nasopharyngitisa cold	2,009	41.3%
Systemic lupus erythematosuslupus, an autoimmune disease	2,002	41.1%
Drug ineffectivethe medicine did not work as expected	1,975	40.6%
Muscle injury	1,966	40.4%
Blistera blister	1,957	40.2%
Rheumatoid arthritisrheumatoid arthritis, an inflammatory joint disease	1,947	40%
Glossodynia	1,932	39.7%
Sleep disorder due to general medical condition, insomnia type	1,928	39.6%
Hand deformity	1,922	39.5%
Hepatic enzyme increasedraised liver enzymes	1,878	38.6%
Helicobacter infection	1,866	38.3%
Wound	1,865	38.3%
Pemphigus	1,858	38.2%
Pericarditisinflammation of the sac around the heart	1,837	37.8%
Duodenal ulcer perforation	1,833	37.7%
Abdominal discomfortstomach discomfort	1,829	37.6%
Ill-defined disordera condition that was not clearly described	1,824	37.5%
Alopeciahair loss	1,799	37%
Arthropathy	1,764	36.3%
Discomfort	1,723	35.4%
Contusiona bruise	1,720	35.3%
Anti-cyclic citrullinated peptide antibody positive	1,669	34.3%
Therapeutic product effect decreased	1,617	33.2%
Drug intolerancethe medicine was not tolerated	1,596	32.8%
Contraindicated product administered	1,457	29.9%
Off label useused for a purpose or in a way not on the label	1,323	27.2%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	1,271	26.1%

Download all 556 terms of Sulfamethoxazole (CSV)

The counts add to more than 4,866 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 Sulfamethoxazole, 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	3	3	0	0	2	0	0	1	0
2005	6	6	2	0	1	0	0	4	0
2006	6	4	1	0	0	0	0	3	2
2007	9	9	2	2	3	0	0	7	0
2008	7	7	1	0	4	0	0	4	0
2009	12	12	3	0	7	0	0	3	0
2010	21	21	3	2	7	1	0	15	0
2011	25	24	7	6	15	1	0	12	1
2012	33	25	7	5	12	1	1	18	8
2013	38	24	7	2	8	1	2	13	14
2014	39	25	4	0	8	4	0	22	14
2015	29	18	2	0	4	0	0	15	11
2016	46	24	4	1	7	0	2	20	22
2017	39	16	2	0	6	3	0	10	23
2018	73	45	8	3	29	1	0	28	28
2019	201	112	9	3	50	2	1	105	89
2020	192	171	12	11	79	26	0	132	21
2021	658	645	6	13	161	317	3	552	13
2022	687	679	19	47	264	407	12	554	8
2023	382	371	83	138	228	240	35	298	11
2024	912	906	570	617	751	675	135	862	6
2025	904	899	591	615	733	689	235	875	5
2026	544	533	418	419	468	439	247	522	11

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 Sulfamethoxazole, 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 Sulfamethoxazole, by the year in which FDA received them
Year	Reports
2004	3
2005	6
2006	5
2007	11
2008	7
2009	12
2010	20
2011	28
2012	38
2013	38
2014	47
2015	43
2016	63
2017	51
2018	123
2019	239
2020	244
2021	824
2022	640
2023	427
2024	973
2025	739
2026	285

Reports that name Sulfamethoxazole, 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 Sulfamethoxazole
Age	Reports	Share
Under 2	14	0.3%
2 to 11	43	0.9%
12 to 17	59	1.2%
18 to 44	2,246	46.2%
45 to 64	604	12.4%
65 to 74	256	5.3%
75 and over	179	3.7%
Age not given	1,465	30.1%

Sex of the patient in the reports that name Sulfamethoxazole
Sex	Reports	Share
Female	3,475	71.4%
Male	582	12%
Unknown or not given	809	16.6%

Type of reporter in the reports that name Sulfamethoxazole
Reporter	Reports	Share
Physician	1,178	24.2%
Pharmacist	65	1.3%
Other health professional	3,102	63.7%
Lawyer	1	under 0.1%
Consumer or non-health professional	464	9.5%
Not given	56	1.2%

Age and sex are as the report gives them. The reporter is the primary source in the report. 9.9% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Sulfamethoxazole record
Indication as recorded (MedDRA)	Reports	Share
Rheumatoid arthritis	475	9.8%
Prophylaxis	55	1.1%
Infection prophylaxis	40	0.8%
Opportunistic infection prophylaxis	25	0.5%
Anti-infective therapy	22	0.5%
Urinary tract infection	17	0.3%

The reporter fills in the indication, and the field is often empty. Each share is of all 4,866 reports.

Drugs in the same reports

Other drugs that the reports of Sulfamethoxazole name, in any role, in order of name
Drug	Reports that name the two
Acetaminophen	3,028
Actemra	2,916
Cimzia	2,916
Enbrel	2,909
Humira	2,872
Methotrexate	3,200
Orencia	3,018
Prednisone	3,573
Simponi	3,114
Sulfasalazine	2,982

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

Sulfadiazine next in the A to Z list
Sulfamethoxazole + Trimethoprim next in the A to Z list
Sulfa next in the A to Z list
Sulfamethoxazole and trimethoprim next in the A to Z list
Sugammadex sodium next in the A to Z list
Sulfamethoxazole W/Trimethoprim next in the A to Z list
Sugammadex next in the A to Z list
Sulfamethoxazole, trimethoprim next in the A to Z list
Sufentanil citrate next in the A to Z list
Sulfamethoxazole-Trimethoprim next in the A to Z list
Sufentanil next in the A to Z list
Sulfasalazine next in the A to Z list

These links are for navigation. No count selected them.

Official pages

DailyMed labels for SulfamethoxazoleThe 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. Sulfamethoxazole: adverse event reports that FDA received. https://reportedreactions.com/drug/sulfamethoxazole/ 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 Sulfamethoxazole as a suspect or interacting product. The 7,105 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 Sulfamethoxazole 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 Sulfamethoxazole?

No. It is a count of what people reported to FDA: 4,866 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?

Other health professional (63.7%), physician (24.2%) and consumer or non-health professional (9.5%). 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.

To the top of the page