Reported Reactions

Drugs › Alkylating drug

Generic name

Ifosfamide: adverse event reports filed with FDA

18,658 reports list it as a suspect or interacting product, 2004–2026. Class: Alkylating drug. Also reported as Ifosfamide Injection 2g, Ifosfamide Injection 1g, Ifosfamide Injection.

18,658
reports as suspect product
0.1% of all reports · about 829 a year
1,325
reports, 12 months to June 2026
1,536 in the 12 months before
98.2%
marked serious by the reporter
93.5% across the class
20%
record death among outcomes, as reported
3,734 reports · not verified by FDA

18,658 adverse event reports received by FDA list ifosfamide, a generic name as a suspect or interacting product, from January 2004 to June 2026. A further 2,657 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 1,325 reports listed it, down 14% from 1,536 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 829 reports a year and 0.1% of the 20,646,523 reports in the database, and 7.4% 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 febrile neutropenia (13.4%), off label use (13.2%) and disease progression (10.2%). A report can list several reactions, so shares add to more than 100%; 1,799 different terms appear across these reports. Febrile neutropenia is recorded in 13.4% of these reports, a larger share than in the median alkylating drug drug (4.9%).

98.2% of the reports are marked serious by the reporter (93.5% across the class); 20% record death among the outcomes and 30.7% record hospitalisation, as reported. 47.2% of the reports came from other health professionals, and the largest patient age group is 18 to 44 (20.5%). 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

0122244Jul 2021: 89Aug 2021: 114Sep 2021: 168Oct 2021: 173Nov 2021: 113Dec 2021: 1612022Jan 2022: 117Feb 2022: 127Mar 2022: 226Apr 2022: 177May 2022: 179Jun 2022: 145Jul 2022: 128Aug 2022: 141Sep 2022: 136Oct 2022: 120Nov 2022: 143Dec 2022: 1982023Jan 2023: 171Feb 2023: 244Mar 2023: 200Apr 2023: 190May 2023: 211Jun 2023: 213Jul 2023: 176Aug 2023: 136Sep 2023: 110Oct 2023: 102Nov 2023: 189Dec 2023: 1412024Jan 2024: 130Feb 2024: 145Mar 2024: 133Apr 2024: 118May 2024: 128Jun 2024: 106Jul 2024: 198Aug 2024: 128Sep 2024: 110Oct 2024: 173Nov 2024: 122Dec 2024: 1622025Jan 2025: 112Feb 2025: 84Mar 2025: 134Apr 2025: 117May 2025: 97Jun 2025: 99Jul 2025: 182Aug 2025: 132Sep 2025: 101Oct 2025: 68Nov 2025: 90Dec 2025: 1152026Jan 2026: 85Feb 2026: 55Mar 2026: 91Apr 2026: 123May 2026: 143Jun 2026: 140

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

01,0422,0832004: 14620042005: 1462006: 1112007: 18120072008: 1822009: 2062010: 22220102011: 5232012: 5932013: 45420132014: 3812015: 7792016: 75120162017: 1,0942018: 1,1162019: 1,24820192020: 1,5542021: 1,4292022: 1,83720222023: 2,0832024: 1,6532025: 1,33120252026: 637

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Ifosfamide reports recording the termmedian drug in alkylating drug

  1. Febrile neutropeniafever with low white blood cells13.4%2,508
  2. Off label useused for a purpose or in a way not on the label13.2%2,457
  3. Disease progressionthe disease advanced10.2%1,898
  4. Neutropenialow neutrophils, a type of white blood cell9.2%1,715
  5. Thrombocytopenialow platelets7.5%1,401
  6. Drug ineffectivethe medicine did not work as expected7.4%1,386
  7. Anaemialow red blood cells6.2%1,156
  8. Pyrexiafever4.5%832
  9. Product use in unapproved indicationused for a purpose not on the label4.3%809
  10. Infectionan infection, type not specified4.1%763
  11. Sepsisa severe body-wide response to infection4%738
  12. Pancytopenialow counts of all blood cells3.9%736
  13. Vomitingbeing sick3.6%673
  14. Nauseafeeling sick3.5%650
  15. Diarrhoealoose or frequent stools3.1%571
  16. Cytopenia2.8%523
  17. Deaththe patient died; cause not stated by this term2.5%469
  18. Leukopenialow white blood cells2.4%446
  19. Pneumonialung infection2.1%392
  20. Acute kidney injurysudden loss of kidney function2%382
  21. Haemorrhagebleeding1.9%363
  22. Toxicity to various agentspoisoning or toxic effect of one or more substances1.9%361

Top 30 of 1,799 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

Death20%3,734
Life-threatening8%1,499
Hospitalisation (initial or prolonged)30.7%5,732
Disability1.1%210
Congenital anomaly0.2%46
Other serious71.4%13,318
Not serious1.8%337

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 21.6%302
2 to 118.9%1,661
12 to 179.2%1,722
18 to 4420.5%3,820
45 to 6418.7%3,484
65 to 747.9%1,476
75 and over1.3%247
Age not given31.9%5,946

Patient sex

Female32.5%6,061
Male45.3%8,451
Not given22.2%4,146

Who reported

Physician39.8%7,426
Pharmacist3.6%681
Other health professional47.2%8,809
Lawyer0%3
Consumer or non-health professional5.2%974
Not given4.1%765

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 25.1% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Diffuse large b-cell lymphoma2,35512.6%
Ewing's sarcoma9084.9%
Osteosarcoma5913.2%
Hodgkin's disease4362.3%
B-cell lymphoma3812%
Central nervous system lymphoma2771.5%

The indication field is filled in by the reporter and is often blank; shares are of all 18,658 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Ifosfamide reports
Etoposide12,91369.2%
Cyclophosphamide7,12538.2%
Carboplatin6,98037.4%
Vincristine6,08632.6%
Doxorubicin6,05232.4%
Rituximab5,52629.6%
Cisplatin4,33623.2%
Methotrexate4,29323%
Dexamethasone4,17122.4%
Cytarabine4,06121.8%

Other products listed in reports where Ifosfamide 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

MeasureIfosfamideAlkylating drugAll reports
Reports as suspect product18,658253,20520,646,523
Share of that pool—7.4%0.1%
Reports, latest 12 months1,325—1,332,454
Marked serious98.2%93.5%57.4%
Death recorded among outcomes, per 1,000 reports20020891
Hospitalisation recorded, per 1,000 reports307333213
Consumer-filed share5.2%6.3%45.8%
Top term, share of reportsFebrile neutropenia 13.4%median 4.9%0.3%

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%
Melphalangeneric17,19095698.5%
Temozolomidegeneric15,3241,05582.3%
Busulfangeneric11,8251,09594.9%
Thiotepageneric7,8531,03598.8%
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 Ifosfamide reports

How many adverse event reports has FDA received for Ifosfamide?

18,658 reports list Ifosfamide as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1,325 of them arrived in the latest 12 months. Another 2,657 list it only as a concomitant medication.

What reactions are recorded in Ifosfamide reports?

febrile neutropenia (13.4%), off label use (13.2%), disease progression (10.2%), neutropenia (9.2%) and thrombocytopenia (7.5%). 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 Ifosfamide was responsible.

How serious are the reports?

98.2% are marked serious by the reporter. Among the outcomes recorded, 20% of reports include death and 30.7% 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 (47.2%), physician (39.8%) and consumer or non-health professional (5.2%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Ifosfamide rising?

1,325 reports in the 12 months to June 2026, down 14% from 1,536 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 Ifosfamide 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 Ifosfamide?

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 Ifosfamide as a suspect or interacting product; reports listing it only as a concomitant medication (2,657) 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.