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Fludarabine Side Effects

The most commonly reported side effects of fludarabine include off label use, cytokine release syndrome, and pyrexia, based on 41,792 FDA adverse event reports from 2004 to 2025. 6.5% of reports found the drug to be ineffective.

#1 Reported: Off Label UseAll side effects ↓Top Co-Medication: CyclophosphamideDrug interactions ↓54% of Reports Are AdultDemographics ↓

Fludarabine side effects

Percentages show how often each reaction appears relative to total reports for fludarabine.

1
Off Label Use9.8%4,111
2
Cytokine Release Syndrome6.7%2,813
3
Drug Ineffective6.5%2,729
4
Pyrexia6.2%2,580
5
Febrile Neutropenia6.1%2,558
6
Product Use In Unapproved Indication5.2%2,169
7
Neutropenia4.0%1,678
8
Cytomegalovirus Infection3.5%1,466
9
Thrombocytopenia3.3%1,392
10
Sepsis3.2%1,329
11
Mucosal Inflammation2.9%1,225
12
Pneumonia2.9%1,220
13
Pancytopenia2.8%1,186
14
Acute Graft Versus Host Disease2.8%1,183
15
Infection2.8%1,178

These are voluntary reports and do not establish that fludarabine caused these reactions.

Report severity

97.8%Serious40,874 reports
29.5%Hospitalizations12,341 reports
31.8%Fatal13,271 reports

Seriousness is determined by the reporter, not by OpenClaim.

Fludarabine drug interactions

Other drugs that appear in adverse event reports alongside fludarabine. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Cyclophosphamide37.7%15,751
2
Rituximab21.4%8,946
3
Busulfan18.6%7,762
4
Cyclosporine16.0%6,677
5
Mycophenolate14.5%6,055
6
Cytarabine11.5%4,808
7
Tacrolimus11.2%4,692
8
Methotrexate10.7%4,461
9
Melphalan10.1%4,221
10
Thiotepa9.8%4,093
11
Alemtuzumab7.6%3,181
12
Vincristine-sulfate7.1%2,981
13
Dexamethasone6.5%2,701
14
Prednisone6.4%2,673
15
Doxorubicin-hydrochloride6.0%2,523

Taken alongside

1
Cyclophosphamide14.5%6,063
2
Acyclovir10.9%4,558
3
Methotrexate6.6%2,761
4
Cyclosporine6.6%2,752
5
Sulfamethoxazole6.2%2,575
6
Tacrolimus5.6%2,334
7
Busulfan5.6%2,332
8
Fluconazole5.1%2,116
9
Acetaminophen5.1%2,113
10
Mycophenolate5.1%2,113
11
Trimethoprim4.9%2,044
12
Melphalan4.8%2,002
13
Methylprednisolone4.6%1,943
14
Allopurinol3.9%1,650
15
Ondansetron3.9%1,637

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports fludarabine side effects

30.8% of fludarabine adverse event reports involve female patients and 45.7% involve male patients. The largest age group is adult at 54%. These figures reflect who reports side effects, not underlying risk.

Sex

Female30.8%
Male45.7%
Unknown23.5%

Age group

< 24.7%
2–1113.6%
12–177.1%
18–6454.5%
65+20.2%

What is fludarabine used for

Conditions and purposes for which patients were taking fludarabine when the adverse event was reported.

Activated Pi3 Kinase Delta SyndromeAcute Biphenotypic LeukaemiaAcute Graft Versus Host DiseaseAcute Haemorrhagic LeukoencephalitisAcute LeukaemiaAcute LeukemiaAcute Lymphocytic LeukaemiaAcute Lymphocytic Leukaemia (in Remission)Acute Lymphocytic Leukaemia RecurrentAcute Lymphocytic Leukaemia RefractoryAcute Megakaryocytic LeukaemiaAcute Monocytic LeukaemiaAcute Monocytic Leukaemia (in Remission)Acute Myeloid LeukaemiaAcute Myeloid Leukaemia (in Remission)

Showing 15 of 903 indications

Fludarabine brand names and reporting trend

Fludarabine is sold under the brand name Oforta.

Brand names

Oforta12,667

Quarterly reports (2004–2025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking fludarabine with another medication?

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