Reported Reactions

Drugs › Alkylating drug

Generic name

Bendamustine hydrochloride: adverse event reports filed with FDA

6,941 reports list it as a suspect or interacting product, 2009–2026. Class: Alkylating drug.

6,941
reports as suspect product
0% of all reports · about 419 a year
253
reports, 12 months to June 2026
341 in the 12 months before
96%
marked serious by the reporter
93.5% across the class
19.5%
record death among outcomes, as reported
1,353 reports · not verified by FDA

Between December 2009 and June 2026, 6,941 adverse event reports received by FDA list bendamustine hydrochloride, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (973) are left out of every figure here.

In the 12 months to June 2026, 253 reports listed it, down 26% from 341 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 419 reports a year and 0% of the 20,646,523 reports in the database, and 2.7% 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 (13.9%), pyrexia (7.4%) and disease progression (6.5%). A report can list several reactions, so shares add to more than 100%; 1,032 different terms appear across these reports. Off label use is recorded in 13.9% of these reports, a larger share than in the median alkylating drug drug (8.5%).

96% of the reports are marked serious by the reporter (93.5% across the class); 19.5% record death among the outcomes and 42.1% record hospitalisation, as reported. 55.1% of the reports came from physicians, and the largest patient age group is 65 to 74 (28.2%). 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

082163Jul 2021: 48Aug 2021: 47Sep 2021: 75Oct 2021: 70Nov 2021: 74Dec 2021: 842022Jan 2022: 60Feb 2022: 52Mar 2022: 86Apr 2022: 85May 2022: 163Jun 2022: 125Jul 2022: 128Aug 2022: 83Sep 2022: 110Oct 2022: 82Nov 2022: 92Dec 2022: 1202023Jan 2023: 93Feb 2023: 95Mar 2023: 68Apr 2023: 62May 2023: 77Jun 2023: 68Jul 2023: 62Aug 2023: 92Sep 2023: 68Oct 2023: 56Nov 2023: 55Dec 2023: 622024Jan 2024: 64Feb 2024: 41Mar 2024: 59Apr 2024: 72May 2024: 65Jun 2024: 46Jul 2024: 32Aug 2024: 29Sep 2024: 39Oct 2024: 82Nov 2024: 26Dec 2024: 272025Jan 2025: 27Feb 2025: 14Mar 2025: 14Apr 2025: 21May 2025: 11Jun 2025: 19Jul 2025: 34Aug 2025: 12Sep 2025: 29Oct 2025: 14Nov 2025: 19Dec 2025: 222026Jan 2026: 28Feb 2026: 16Mar 2026: 15Apr 2026: 16May 2026: 31Jun 2026: 17

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

05931,1862009: 120092010: 22011: 1320112012: 1152013: 4220132014: 2692015: 41720152016: 4322017: 40020172018: 5802019: 52520192020: 5332021: 62720212022: 1,1862023: 85820232024: 5822025: 23620252026: 123

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Bendamustine hydrochloride reports recording the termmedian drug in alkylating drug

  1. Off label useused for a purpose or in a way not on the label13.9%963
  2. Pyrexiafever7.4%511
  3. Disease progressionthe disease advanced6.5%452
  4. Product use in unapproved indicationused for a purpose not on the label5.7%393
  5. Drug ineffectivethe medicine did not work as expected5.2%360
  6. Febrile neutropeniafever with low white blood cells4.9%340
  7. Neutropenialow neutrophils, a type of white blood cell4.7%326
  8. Pneumonialung infection4.4%306
  9. Anaemialow red blood cells4.1%285
  10. Covid-19COVID-19 infection4%277
  11. Platelet count decreasedlow platelet count3.9%268
  12. Thrombocytopenialow platelets3.7%255
  13. Deaththe patient died; cause not stated by this term3.2%220
  14. Diarrhoealoose or frequent stools3.2%219
  15. Pancytopenialow counts of all blood cells3.1%216
  16. White blood cell count decreasedlow white cell count2.9%200
  17. Rashskin rash2.7%188
  18. Nauseafeeling sick2.6%180
  19. Sepsisa severe body-wide response to infection2.6%178
  20. Product use issuea problem in how the product was used2.5%172
  21. Acute kidney injurysudden loss of kidney function2.4%166
  22. Infectionan infection, type not specified2.4%164
  23. Infusion related reactiona reaction during or soon after an infusion2.3%163
  24. Cytopenia2.2%153

Top 30 of 1,032 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

Death19.5%1,353
Life-threatening6.1%424
Hospitalisation (initial or prolonged)42.1%2,923
Disability1.3%92
Congenital anomaly0.4%28
Other serious65.3%4,531
Not serious4%281

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 20%2
2 to 110.1%7
12 to 170.2%16
18 to 444.8%334
45 to 6422.3%1,549
65 to 7428.2%1,955
75 and over20.2%1,399
Age not given24.2%1,679

Patient sex

Female33.3%2,314
Male51%3,541
Not given15.6%1,086

Who reported

Physician55.1%3,824
Pharmacist3%205
Other health professional28.7%1,995
Lawyer0%1
Consumer or non-health professional10.6%737
Not given2.6%179

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 13.9% 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 lymphoma1,00814.5%
Follicular lymphoma71810.3%
Chronic lymphocytic leukaemia5908.5%
B-cell lymphoma5247.5%
Mantle cell lymphoma3885.6%
Non-hodgkin's lymphoma2263.3%

The indication field is filled in by the reporter and is often blank; shares are of all 6,941 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Bendamustine hydrochloride reports
Rituximab4,09959.1%
Cyclophosphamide1,36419.7%
Prednisone1,08115.6%
Dexamethasone1,01014.6%
Polatuzumab vedotin79911.5%
Obinutuzumab6869.9%
Vincristine6609.5%
Doxorubicin6599.5%
Vincristine sulfate6409.2%
Cytarabine6309.1%

Other products listed in reports where Bendamustine hydrochloride 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

MeasureBendamustine hydrochlorideAlkylating drugAll reports
Reports as suspect product6,941253,20520,646,523
Share of that pool—2.7%0%
Reports, latest 12 months253—1,332,454
Marked serious96%93.5%57.4%
Death recorded among outcomes, per 1,000 reports19520891
Hospitalisation recorded, per 1,000 reports421333213
Consumer-filed share10.6%6.3%45.8%
Top term, share of reportsOff label use 13.9%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%
Thiotepageneric7,8531,03598.8%
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 Bendamustine hydrochloride reports

How many adverse event reports has FDA received for Bendamustine hydrochloride?

6,941 reports list Bendamustine hydrochloride as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 253 of them arrived in the latest 12 months. Another 973 list it only as a concomitant medication.

What reactions are recorded in Bendamustine hydrochloride reports?

off label use (13.9%), pyrexia (7.4%), disease progression (6.5%), product use in unapproved indication (5.7%) and drug ineffective (5.2%). 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 Bendamustine hydrochloride was responsible.

How serious are the reports?

96% are marked serious by the reporter. Among the outcomes recorded, 19.5% of reports include death and 42.1% 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 (55.1%), other health professional (28.7%) and consumer or non-health professional (10.6%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Bendamustine hydrochloride rising?

253 reports in the 12 months to June 2026, down 26% from 341 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 Bendamustine hydrochloride 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 Bendamustine hydrochloride?

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 Bendamustine hydrochloride as a suspect or interacting product; reports listing it only as a concomitant medication (973) 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.