Imuran: adverse event reports filed with FDA

5,749

reports as suspect product

0% of all reports · about 256 a year

407

reports, 12 months to June 2026

571 in the 12 months before

87.3%

marked serious by the reporter

90.3% across the class

13.2%

record death among outcomes, as reported

756 reports · not verified by FDA

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 Imuran reports recording the termmedian drug in purine antimetabolite

1. Drug ineffectivethe medicine did not work as expected27.7%1,591
2. Off label useused for a purpose or in a way not on the label12.4%713
3. Rheumatoid arthritisrheumatoid arthritis, an inflammatory joint disease11.9%687
4. Drug intolerancethe medicine was not tolerated11.5%664
5. Drug hypersensitivityan allergic-type reaction to a medicine10.2%587
6. Pain in extremitypain in an arm or leg10.2%584
7. Condition aggravatedthe condition being treated got worse9.7%557
8. Nauseafeeling sick9.7%556
9. Arthralgiajoint pain9.2%527
10. Pneumonialung infection8.7%501
11. Dyspnoeashortness of breath8.5%491
12. Diarrhoealoose or frequent stools8%460
13. Rashskin rash7.9%454
14. Treatment failurethe treatment did not work7.8%451
15. Painpain, site not specified7.7%441
16. Fatiguetiredness7.6%438
17. Hypersensitivityan allergic-type reaction7.4%427
18. Joint swellinga swollen joint7.2%414
19. Therapeutic product effect incomplete6.4%367
20. Malaisegeneral feeling of being unwell6.3%362
21. Therapeutic product effect decreased6.2%356
22. Urticariahives5.8%333
23. Muscle spasmsmuscle cramps5.5%317
24. Stomatitissore mouth5.5%314
25. Wheezingwheezing5.4%311
26. Vomitingbeing sick5.2%297
27. Pyrexiafever5.1%295
28. Weight decreasedweight loss4.9%280
29. Abdominal painstomach or belly pain4.9%279
30. Lung disordera lung problem, type not specified4.7%273

Top 30 of 1,267 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 5 drugs in the purine antimetabolite 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 49,725 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

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 28.8% of reports give the United States as the country of the event or reporter.

Reason for use recorded

The indication field is filled in by the reporter and is often blank; shares are of all 5,749 reports.

Drugs most often listed in the same reports

Other products listed in reports where Imuran is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

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 purine antimetabolite class

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.

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 Imuran as a suspect or interacting product; reports listing it only as a concomitant medication (18,071) 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.