Reported Reactions

Drugs › Kinase inhibitor

Generic name

Imatinib mesylate: adverse event reports filed with FDA

3,482 reports list it as a suspect or interacting product, 2004–2026. Class: Kinase inhibitor. Also reported as Imatinib Mesylate Tablets, Imatinib Mesylate 400mg Tabs, Imatinib Mesylate 400mg.

3,482
reports as suspect product
0% of all reports · about 157 a year
234
reports, 12 months to June 2026
248 in the 12 months before
83.5%
marked serious by the reporter
70.8% across the class
26.7%
record death among outcomes, as reported
930 reports · not verified by FDA

Between April 2004 and June 2026, 3,482 adverse event reports received by FDA list imatinib mesylate, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (331) are left out of every figure here.

In the 12 months to June 2026, 234 reports listed it, close to the 248 of 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 157 reports a year and 0% of the 20,646,523 reports in the database, and 0.4% of the reports for the kinase inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded death (14.3%), nausea (7.2%) and diarrhoea (6.2%). A report can list several reactions, so shares add to more than 100%; 660 different terms appear across these reports. Death is recorded in 14.3% of these reports, a larger share than in the median kinase inhibitor drug (7.6%).

83.5% of the reports are marked serious by the reporter (70.8% across the class); 26.7% record death among the outcomes and 27.7% record hospitalisation, as reported. 44.1% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (19.6%). 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

02856Jul 2021: 8Aug 2021: 20Sep 2021: 15Oct 2021: 50Nov 2021: 48Dec 2021: 352022Jan 2022: 19Feb 2022: 38Mar 2022: 56Apr 2022: 28May 2022: 30Jun 2022: 23Jul 2022: 18Aug 2022: 31Sep 2022: 23Oct 2022: 30Nov 2022: 43Dec 2022: 332023Jan 2023: 28Feb 2023: 34Mar 2023: 36Apr 2023: 37May 2023: 40Jun 2023: 34Jul 2023: 23Aug 2023: 44Sep 2023: 46Oct 2023: 25Nov 2023: 18Dec 2023: 282024Jan 2024: 24Feb 2024: 26Mar 2024: 28Apr 2024: 40May 2024: 28Jun 2024: 19Jul 2024: 24Aug 2024: 35Sep 2024: 30Oct 2024: 30Nov 2024: 22Dec 2024: 162025Jan 2025: 19Feb 2025: 13Mar 2025: 15Apr 2025: 16May 2025: 11Jun 2025: 17Jul 2025: 23Aug 2025: 14Sep 2025: 35Oct 2025: 18Nov 2025: 18Dec 2025: 102026Jan 2026: 14Feb 2026: 17Mar 2026: 17Apr 2026: 30May 2026: 20Jun 2026: 18

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

03647272004: 820042005: 62006: 252007: 7820072008: 762009: 952010: 2820102011: 1812012: 7272014: 720142015: 22016: 272017: 5820172018: 902019: 1742020: 22620202021: 2602022: 3722023: 39320232024: 3222025: 2092026: 1162026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Imatinib mesylate reports recording the termmedian drug in kinase inhibitor

  1. Deaththe patient died; cause not stated by this term14.3%497
  2. Nauseafeeling sick7.2%249
  3. Diarrhoealoose or frequent stools6.2%216
  4. Drug ineffectivethe medicine did not work as expected5.2%182
  5. Fatiguetiredness4.7%163
  6. Vomitingbeing sick4.1%144
  7. Dyspnoeashortness of breath4%138
  8. Neoplasm malignanta cancer, type not specified3.6%126
  9. Abdominal painstomach or belly pain3.4%119
  10. Pyrexiafever3.4%119
  11. Astheniaweakness or lack of energy3.3%116
  12. Falla fall3.1%107
  13. Sepsisa severe body-wide response to infection3%106
  14. Pruritusitching3%105
  15. Off label useused for a purpose or in a way not on the label3%104
  16. Dizzinesslight-headedness or unsteadiness2.8%97
  17. Ascitesfluid in the abdomen2.7%93
  18. Arthralgiajoint pain2.6%90
  19. Drug interactionan interaction between medicines2.4%85
  20. Malaisegeneral feeling of being unwell2.4%83
  21. Headachehead pain2.4%82
  22. Chillschills or shivering2.3%81
  23. Rashskin rash2.3%79
  24. Cardio-respiratory arrestthe heart and breathing stopped2.2%76
  25. Drug intolerancethe medicine was not tolerated2.2%76
  26. Decreased appetitereduced appetite2.1%74
  27. Thrombocytopenialow platelets2.1%73
  28. Insomniadifficulty sleeping2.1%72

Top 30 of 660 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 100 drugs in the kinase inhibitor 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

Death26.7%930
Life-threatening3.8%131
Hospitalisation (initial or prolonged)27.7%965
Disability1.5%51
Congenital anomaly0.2%6
Other serious45%1,566
Not serious16.5%573

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 849,161 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

Under 20.3%9
2 to 112.2%77
12 to 171.7%59
18 to 447.9%275
45 to 6419.6%681
65 to 7413%452
75 and over11.7%409
Age not given43.7%1,520

Patient sex

Female42.6%1,482
Male48%1,673
Not given9.4%327

Who reported

Physician22.1%768
Pharmacist4.2%145
Other health professional44.1%1,535
Lawyer0%0
Consumer or non-health professional17.9%624
Not given11.8%410

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 45% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Chronic myeloid leukaemia1,18133.9%
Gastrointestinal stromal tumour44212.7%
Acute lymphocytic leukaemia1765.1%
Philadelphia positive chronic myeloid leukaemia601.7%
Philadelphia positive acute lymphocytic leukaemia310.9%
Leukaemia260.7%

The indication field is filled in by the reporter and is often blank; shares are of all 3,482 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Imatinib mesylate reports
Aspirin1474.2%
Dasatinib1353.9%
Acetaminophen1002.9%
Nilotinib982.8%
Hydroxyurea962.8%
Human immunoglobulin g922.6%
Simvastatin882.5%
Adalimumab852.4%
Ezetimibe822.4%
Methotrexate822.4%

Other products listed in reports where Imatinib mesylate 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

MeasureImatinib mesylateKinase inhibitorAll reports
Reports as suspect product3,482849,16120,646,523
Share of that pool—0.4%0%
Reports, latest 12 months234—1,332,454
Marked serious83.5%70.8%57.4%
Death recorded among outcomes, per 1,000 reports26719091
Hospitalisation recorded, per 1,000 reports277264213
Consumer-filed share17.9%42.3%45.8%
Top term, share of reportsDeath 14.3%median 7.6%4.1%

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 kinase inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Ibrancebrand81,9122,38047.1%
Imbruvicabrand67,0392,28374.4%
Cabometyxbrand41,8184,90440.4%
Sutentbrand33,21517574.5%
Afinitorbrand30,70616171.3%
Sprycelbrand27,25555749.7%
Tasignabrand24,91132870.9%
Kisqalibrand24,6033,41379.2%
Ofevbrand23,9072,43466.9%
Gleevecbrand23,1328174.7%
Tagrissobrand23,0851,41092.3%
Lenvimabrand22,3502,64387.3%
Votrientbrand22,08411960.9%
Mekinistbrand17,07091664%
Inlytabrand15,69638860.9%

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 Imatinib mesylate reports

How many adverse event reports has FDA received for Imatinib mesylate?

3,482 reports list Imatinib mesylate as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 234 of them arrived in the latest 12 months. Another 331 list it only as a concomitant medication.

What reactions are recorded in Imatinib mesylate reports?

death (14.3%), nausea (7.2%), diarrhoea (6.2%), drug ineffective (5.2%) and fatigue (4.7%). 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 Imatinib mesylate was responsible.

How serious are the reports?

83.5% are marked serious by the reporter. Among the outcomes recorded, 26.7% of reports include death and 27.7% 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?

other health professional (44.1%), physician (22.1%) and consumer or non-health professional (17.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Imatinib mesylate rising?

234 reports in the 12 months to June 2026, close to the 248 of 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 Imatinib mesylate 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 Imatinib mesylate?

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 Imatinib mesylate as a suspect or interacting product; reports listing it only as a concomitant medication (331) 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.