Reported Reactions

Drugs › Cytoprotective agent

Generic name

Mesna: adverse event reports filed with FDA

4,393 reports list it as a suspect or interacting product, 2004–2026. Class: Cytoprotective agent. Also reported as Mesna For Injection, Mesna 7200mg.

4,393
reports as suspect product
0% of all reports · about 195 a year
325
reports, 12 months to June 2026
403 in the 12 months before
98.3%
marked serious by the reporter
98.2% across the class
20.1%
record death among outcomes, as reported
885 reports · not verified by FDA

Between January 2004 and June 2026, 4,393 adverse event reports received by FDA list mesna, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (3,904) are left out of every figure here.

In the 12 months to June 2026, 325 reports listed it, down 19% from 403 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 195 reports a year and 0% of the 20,646,523 reports in the database, and 33% of the reports for the cytoprotective agent 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 (18.1%), pyrexia (8.2%) and off label use (7.4%). A report can list several reactions, so shares add to more than 100%; 843 different terms appear across these reports. Febrile neutropenia is recorded in 18.1% of these reports, a larger share than in the median cytoprotective agent drug (10%).

98.3% of the reports are marked serious by the reporter (98.2% across the class); 20.1% record death among the outcomes and 48.7% record hospitalisation, as reported. 43.1% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (20.9%). 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

03365Jul 2021: 12Aug 2021: 32Sep 2021: 36Oct 2021: 36Nov 2021: 21Dec 2021: 282022Jan 2022: 24Feb 2022: 20Mar 2022: 46Apr 2022: 35May 2022: 26Jun 2022: 23Jul 2022: 20Aug 2022: 34Sep 2022: 17Oct 2022: 28Nov 2022: 34Dec 2022: 252023Jan 2023: 34Feb 2023: 25Mar 2023: 35Apr 2023: 28May 2023: 30Jun 2023: 32Jul 2023: 19Aug 2023: 30Sep 2023: 21Oct 2023: 31Nov 2023: 38Dec 2023: 282024Jan 2024: 39Feb 2024: 38Mar 2024: 40Apr 2024: 33May 2024: 37Jun 2024: 24Jul 2024: 46Aug 2024: 65Sep 2024: 39Oct 2024: 41Nov 2024: 28Dec 2024: 422025Jan 2025: 18Feb 2025: 25Mar 2025: 26Apr 2025: 22May 2025: 16Jun 2025: 35Jul 2025: 35Aug 2025: 34Sep 2025: 22Oct 2025: 44Nov 2025: 13Dec 2025: 202026Jan 2026: 20Feb 2026: 20Mar 2026: 39Apr 2026: 31May 2026: 17Jun 2026: 30

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

02364722004: 5720042005: 522006: 552007: 5020072008: 642009: 712010: 10620102011: 1612012: 1202013: 14420132014: 1382015: 1602016: 13620162017: 1712018: 2972019: 30620192020: 3282021: 3552022: 33220222023: 3512024: 4722025: 31020252026: 157

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Mesna reports recording the termmedian drug in cytoprotective agent

  1. Febrile neutropeniafever with low white blood cells18.1%794
  2. Pyrexiafever8.2%360
  3. Off label useused for a purpose or in a way not on the label7.4%326
  4. Neutropenialow neutrophils, a type of white blood cell6.3%277
  5. Vomitingbeing sick5.3%234
  6. Sepsisa severe body-wide response to infection4.7%207
  7. Pancytopenialow counts of all blood cells4.4%195
  8. Disease progressionthe disease advanced4.3%189
  9. Diarrhoealoose or frequent stools4.2%183
  10. Thrombocytopenialow platelets4.1%182
  11. Anaemialow red blood cells4.1%178
  12. Nauseafeeling sick4%176
  13. Deaththe patient died; cause not stated by this term3.4%149
  14. Pneumonialung infection3.3%145
  15. Hypotensionlow blood pressure3.2%139
  16. Bacterial infectiona bacterial infection3.1%138
  17. Drug ineffectivethe medicine did not work as expected2.7%117
  18. Platelet count decreasedlow platelet count2.6%115
  19. Product use in unapproved indicationused for a purpose not on the label2.5%112
  20. Viral infectiona viral infection2.5%111
  21. White blood cell count decreasedlow white cell count2.5%108
  22. Infectionan infection, type not specified2.4%107
  23. Pseudomonal sepsis2.4%107
  24. Acute kidney injurysudden loss of kidney function2.1%91

Top 30 of 843 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 3 drugs in the cytoprotective agent 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

Death20.1%885
Life-threatening6.9%301
Hospitalisation (initial or prolonged)48.7%2,138
Disability1.4%63
Congenital anomaly0.4%18
Other serious58.2%2,555
Not serious1.7%73

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 13,325 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 22.8%123
2 to 1110.1%444
12 to 175.5%243
18 to 4419.1%841
45 to 6420.9%919
65 to 7410.5%461
75 and over2.5%110
Age not given28.5%1,252

Patient sex

Female36.3%1,594
Male41.1%1,804
Not given22.6%995

Who reported

Physician38.7%1,702
Pharmacist5.4%236
Other health professional43.1%1,892
Lawyer0%2
Consumer or non-health professional5.4%237
Not given7.4%324

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 34.3% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Acute lymphocytic leukaemia4009.1%
Prophylaxis3908.9%
Diffuse large b-cell lymphoma1323%
Sarcoma912.1%
B-cell lymphoma621.4%
Neuroblastoma601.4%

The indication field is filled in by the reporter and is often blank; shares are of all 4,393 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Mesna reports
Cyclophosphamide2,62359.7%
Ifosfamide1,95744.5%
Etoposide1,70038.7%
Dexamethasone1,45033%
Cytarabine1,20227.4%
Methotrexate1,00122.8%
Rituximab97722.2%
Vincristine84419.2%
Doxorubicin80718.4%
Vincristine sulfate79718.1%

Other products listed in reports where Mesna 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

MeasureMesnaCytoprotective agentAll reports
Reports as suspect product4,39313,32520,646,523
Share of that pool—33%0%
Reports, latest 12 months325—1,332,454
Marked serious98.3%98.2%57.4%
Death recorded among outcomes, per 1,000 reports20122891
Hospitalisation recorded, per 1,000 reports487368213
Consumer-filed share5.4%4.9%45.8%
Top term, share of reportsFebrile neutropenia 18.1%median 10%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 cytoprotective agent class

DrugName typeReportsLatest 12 monthsMarked serious
Bleomycingeneric6,34135298%
Bleomycin sulfategeneric2,59110498.5%

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 Mesna reports

How many adverse event reports has FDA received for Mesna?

4,393 reports list Mesna as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 325 of them arrived in the latest 12 months. Another 3,904 list it only as a concomitant medication.

What reactions are recorded in Mesna reports?

febrile neutropenia (18.1%), pyrexia (8.2%), off label use (7.4%), neutropenia (6.3%) and vomiting (5.3%). 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 Mesna was responsible.

How serious are the reports?

98.3% are marked serious by the reporter. Among the outcomes recorded, 20.1% of reports include death and 48.7% 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 (43.1%), physician (38.7%) and not given (7.4%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Mesna rising?

325 reports in the 12 months to June 2026, down 19% from 403 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 Mesna 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 Mesna?

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 Mesna as a suspect or interacting product; reports listing it only as a concomitant medication (3,904) 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.