Reported Reactions

Drugs › Alkylating drug

Generic name

Thiotepa: adverse event reports filed with FDA

7,853 reports list it as a suspect or interacting product, 2004–2026. Class: Alkylating drug. Also reported as Thiotepa For Injection, Thiotepa 600mg.

7,853
reports as suspect product
0% of all reports · about 350 a year
1,035
reports, 12 months to June 2026
879 in the 12 months before
98.8%
marked serious by the reporter
93.5% across the class
27.7%
record death among outcomes, as reported
2,172 reports · not verified by FDA

Between February 2004 and June 2026, 7,853 adverse event reports received by FDA list thiotepa, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (1,464) are left out of every figure here.

In the 12 months to June 2026, 1,035 reports listed it, up 18% from 879 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 350 reports a year and 0% of the 20,646,523 reports in the database, and 3.1% of the reports for the alkylating drug class. How many people take it is not in the data, so a count is not a rate of occurrence.

The reactions recorded most often are off label use (11.1%), febrile neutropenia (9.2%) and mucosal inflammation (8.9%). A report can list several reactions, so shares add to more than 100%; 1,117 different terms appear across these reports. Off label use is recorded in 11.1% of these reports, a larger share than in the median alkylating drug drug (8.5%).

98.8% of the reports are marked serious by the reporter (93.5% across the class); 27.7% record death among the outcomes and 18.4% record hospitalisation, as reported. 48.9% of the reports came from physicians, and the largest patient age group is 2 to 11 (18.2%). 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

0103205Jul 2021: 33Aug 2021: 33Sep 2021: 40Oct 2021: 89Nov 2021: 60Dec 2021: 312022Jan 2022: 42Feb 2022: 45Mar 2022: 55Apr 2022: 63May 2022: 36Jun 2022: 27Jul 2022: 49Aug 2022: 55Sep 2022: 50Oct 2022: 41Nov 2022: 62Dec 2022: 592023Jan 2023: 43Feb 2023: 72Mar 2023: 34Apr 2023: 67May 2023: 48Jun 2023: 34Jul 2023: 48Aug 2023: 27Sep 2023: 15Oct 2023: 22Nov 2023: 30Dec 2023: 522024Jan 2024: 67Feb 2024: 42Mar 2024: 113Apr 2024: 61May 2024: 44Jun 2024: 48Jul 2024: 72Aug 2024: 80Sep 2024: 82Oct 2024: 78Nov 2024: 69Dec 2024: 822025Jan 2025: 55Feb 2025: 41Mar 2025: 68Apr 2025: 47May 2025: 46Jun 2025: 159Jul 2025: 205Aug 2025: 54Sep 2025: 145Oct 2025: 38Nov 2025: 150Dec 2025: 422026Jan 2026: 48Feb 2026: 101Mar 2026: 75Apr 2026: 78May 2026: 52Jun 2026: 47

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

05251,0502004: 3320042005: 322006: 262007: 2820072008: 612009: 732010: 10520102011: 1162012: 392013: 7120132014: 2302015: 1092016: 17720162017: 3792018: 7122019: 71820192020: 8792021: 7002022: 58420222023: 4922024: 8382025: 1,05020252026: 401

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Thiotepa reports recording the termmedian drug in alkylating drug

  1. Off label useused for a purpose or in a way not on the label11.1%870
  2. Febrile neutropeniafever with low white blood cells9.2%726
  3. Product use in unapproved indicationused for a purpose not on the label5.4%426
  4. Pyrexiafever5.3%420
  5. Drug ineffectivethe medicine did not work as expected5.1%398
  6. Cytomegalovirus infection reactivation4.9%388
  7. Acute graft versus host disease in skin4.9%384
  8. Infectionan infection, type not specified4.6%360
  9. Acute graft versus host disease4.6%358
  10. Venoocclusive liver disease4.6%358
  11. Neutropenialow neutrophils, a type of white blood cell4.5%350
  12. Sepsisa severe body-wide response to infection4.4%347
  13. Thrombocytopenialow platelets4%316
  14. Adenovirus infection3.7%290
  15. Human herpesvirus 6 infection3.6%283
  16. Multiple organ dysfunction syndromeseveral organs failing2.9%230
  17. Diarrhoealoose or frequent stools2.9%225
  18. Acute graft versus host disease in intestine2.8%221
  19. Graft versus host disease in skin2.7%214
  20. Chronic graft versus host disease2.6%203
  21. Pneumonialung infection2.5%197
  22. Graft versus host disease in gastrointestinal tract2.4%191
  23. Respiratory failurethe lungs could not supply enough oxygen2.3%180
  24. Disease progressionthe disease advanced2.2%175

Top 30 of 1,117 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 23 drugs in the alkylating drug 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

Death27.7%2,172
Life-threatening9%703
Hospitalisation (initial or prolonged)18.4%1,446
Disability0.8%61
Congenital anomaly0.1%4
Other serious77.2%6,064
Not serious1.2%93

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 253,205 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 27.7%602
2 to 1118.2%1,431
12 to 177.1%558
18 to 4412.1%950
45 to 6413.3%1,041
65 to 742.8%223
75 and over0.5%38
Age not given38.3%3,010

Patient sex

Female30.8%2,416
Male37.8%2,965
Not given31.5%2,472

Who reported

Physician48.9%3,840
Pharmacist1%76
Other health professional44.8%3,516
Lawyer0%1
Consumer or non-health professional2.3%178
Not given3.1%242

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 20% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Allogenic stem cell transplantation1,45718.6%
Bone marrow conditioning regimen1,34017.1%
Stem cell transplant7229.2%
Central nervous system lymphoma3314.2%
Diffuse large b-cell lymphoma2663.4%
Autologous haematopoietic stem cell transplant2623.3%

The indication field is filled in by the reporter and is often blank; shares are of all 7,853 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Thiotepa reports
Fludarabine3,60845.9%
Cyclophosphamide3,44143.8%
Busulfan2,29729.2%
Methotrexate2,04426%
Mycophenolate mofetil1,87623.9%
Etoposide1,64420.9%
Rituximab1,60220.4%
Cyclosporine1,54519.7%
Cytarabine1,27716.3%
Carboplatin1,26616.1%

Other products listed in reports where Thiotepa 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

MeasureThiotepaAlkylating drugAll reports
Reports as suspect product7,853253,20520,646,523
Share of that pool—3.1%0%
Reports, latest 12 months1,035—1,332,454
Marked serious98.8%93.5%57.4%
Death recorded among outcomes, per 1,000 reports27720891
Hospitalisation recorded, per 1,000 reports184333213
Consumer-filed share2.3%6.3%45.8%
Top term, share of reportsOff label use 11.1%median 8.5%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 alkylating drug class

DrugName typeReportsLatest 12 monthsMarked serious
Cyclophosphamidegeneric141,09912,36097.8%
Ifosfamidegeneric18,6581,32598.2%
Melphalangeneric17,19095698.5%
Temozolomidegeneric15,3241,05582.3%
Busulfangeneric11,8251,09594.9%
Bendamustine hydrochloridegeneric6,94125396%
Dacarbazinegeneric6,43151196.3%
Temodarbrand4,6522456.1%
Matulanebrand3,84528415.9%
Carmustinegeneric3,37818099%
Treandabrand3,330366.5%
Chlorambucilgeneric2,4867598.5%
Valchlorbrand2,1141628.4%
Mitomycingeneric2,04111792.4%
Lomustinegeneric1,1009294.8%

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 Thiotepa reports

How many adverse event reports has FDA received for Thiotepa?

7,853 reports list Thiotepa as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1,035 of them arrived in the latest 12 months. Another 1,464 list it only as a concomitant medication.

What reactions are recorded in Thiotepa reports?

off label use (11.1%), febrile neutropenia (9.2%), mucosal inflammation (8.9%), cytomegalovirus infection (5.9%) and product use in unapproved indication (5.4%). 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 Thiotepa was responsible.

How serious are the reports?

98.8% are marked serious by the reporter. Among the outcomes recorded, 27.7% of reports include death and 18.4% 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 (48.9%), other health professional (44.8%) and not given (3.1%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Thiotepa rising?

1,035 reports in the 12 months to June 2026, up 18% from 879 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 Thiotepa 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 Thiotepa?

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 Thiotepa as a suspect or interacting product; reports listing it only as a concomitant medication (1,464) 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.