Brand name · Sulfasalazine
Azulfidine En-Tabs: adverse event reports filed with FDA
519 reports list it as a suspect or interacting product, 2004–2026. Class: Aminosalicylate.
- 519
- reports as suspect product
- 0% of all reports · about 23 a year
- 14
- reports, 12 months to June 2026
- 19 in the 12 months before
- 97.5%
- marked serious by the reporter
- 86.5% across the class
- 7.1%
- record death among outcomes, as reported
- 37 reports · not verified by FDA
Between March 2004 and April 2026, 519 adverse event reports received by FDA list the brand name Azulfidine En-Tabs (sulfasalazine) as a suspect or interacting product. Reports that mention it only as a concomitant medication (729) are left out of every figure here.
In the 12 months to June 2026, 14 reports listed it, down 26% from 19 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 23 reports a year and 0% of the 20,646,523 reports in the database, and 0.9% of the reports for the aminosalicylate class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded pyrexia (6.6%), interstitial lung disease (6.2%) and pneumonia (5.4%). A report can list several reactions, so shares add to more than 100%; 187 different terms appear across these reports. Pyrexia is recorded in 6.6% of these reports, about the same share as in the median aminosalicylate drug (6.6%).
97.5% of the reports are marked serious by the reporter (86.5% across the class); 7.1% record death among the outcomes and 52.2% record hospitalisation, as reported. 50.7% of the reports came from physicians, and the largest patient age group is 75 and over (23.3%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Azulfidine En-Tabs reports recording the termmedian drug in aminosalicylate
- Pyrexiafever6.6%34
- Interstitial lung diseasescarring or inflammation of lung tissue6.2%32
- Pneumonialung infection5.4%28
- Drug eruption5.2%27
- Pancytopenialow counts of all blood cells4%21
- Rashskin rash3.5%18
- Agranulocytosis2.9%15
- Drug reaction with eosinophilia and systemic symptomsDRESS, a severe reaction with rash, fever and organ involvement2.7%14
- Condition aggravatedthe condition being treated got worse2.3%12
- Liver disorder2.3%12
- White blood cell count decreasedlow white cell count2.3%12
- Rheumatoid arthritisrheumatoid arthritis, an inflammatory joint disease2.1%11
- Arthralgiajoint pain1.9%10
- Erythemaskin redness1.9%10
- Malaisegeneral feeling of being unwell1.7%9
- Platelet count decreasedlow platelet count1.7%9
- Pneumonia bacterial1.7%9
- Drug ineffectivethe medicine did not work as expected1.3%7
- Nauseafeeling sick1.3%7
- Oculomucocutaneous syndrome1.3%7
- Alanine aminotransferase increasedraised liver enzyme (ALT)1.2%6
- Diarrhoealoose or frequent stools1.2%6
- Febrile neutropeniafever with low white blood cells1.2%6
- Leukopenialow white blood cells1.2%6
- Renal impairmentreduced kidney function1.2%6
- Sepsisa severe body-wide response to infection1.2%6
- Abdominal painstomach or belly pain1%5
- Arthropathy1%5
Top 30 of 187 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 7 drugs in the aminosalicylate class; it describes the reports, not the patients. 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."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 59,220 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 3.7% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Rheumatoid arthritis | 278 | 53.6% |
| Rheumatic disorder | 5 | 1% |
| Musculoskeletal pain | 4 | 0.8% |
| Ill-defined disorder | 2 | 0.4% |
| Pain | 2 | 0.4% |
The indication field is filled in by the reporter and is often blank; shares are of all 519 reports.
In context
| Measure | Azulfidine En-Tabs | Aminosalicylate | All reports |
|---|---|---|---|
| Reports as suspect product | 519 | 59,220 | 20,646,523 |
| Share of that pool | — | 0.9% | 0% |
| Reports, latest 12 months | 14 | — | 1,332,454 |
| Marked serious | 97.5% | 86.5% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 71 | 113 | 91 |
| Hospitalisation recorded, per 1,000 reports | 522 | 289 | 213 |
| Consumer-filed share | 10.8% | 24.3% | 45.8% |
| Top term, share of reports | Pyrexia 6.6% | median 6.6% | 1.6% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. 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."
Other drugs in the aminosalicylate class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Sulfasalazine | generic | 40,741 | 2,020 | 89.9% |
| Mesalamine | generic | 8,961 | 1,401 | 92% |
| Lialda | brand | 3,749 | 165 | 56.4% |
| Pentasa | brand | 3,082 | 141 | 80.1% |
| Azulfidine | brand | 1,332 | 91 | 68.5% |
| Apriso | brand | 836 | 2 | 42% |
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." A brand and its generic are separate rows because reporters name them separately.
Questions about Azulfidine En-Tabs reports
How many adverse event reports has FDA received for Azulfidine En-Tabs?
519 reports list Azulfidine En-Tabs as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 14 of them arrived in the latest 12 months. Another 729 list it only as a concomitant medication.
What reactions are recorded in Azulfidine En-Tabs reports?
pyrexia (6.6%), interstitial lung disease (6.2%), pneumonia (5.4%), drug eruption (5.2%) and pancytopenia (4%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Azulfidine En-Tabs was responsible.
How serious are the reports?
97.5% are marked serious by the reporter. Among the outcomes recorded, 7.1% of reports include death and 52.2% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
physician (50.7%), pharmacist (26.8%) and consumer or non-health professional (10.8%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Azulfidine En-Tabs rising?
14 reports in the 12 months to June 2026, down 26% from 19 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Azulfidine En-Tabs was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Azulfidine En-Tabs?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. 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 report counts here when it lists Azulfidine En-Tabs as a suspect or interacting product; reports listing it only as a concomitant medication (729) are excluded. 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.