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Bendamustine HCL side effects: what 15,416 FDA adverse event reports show

Bendamustine Hcl · 1,047 reaction terms · 53,092 drug–reaction co-reports · data 2026-09-14
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Drug class

Alkylating drug

FDA label, Indications wording of the closest related product

Label matched

Bendamustine Hcl (Bendamustine)

closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match

Who reports

15,416 reports · 96% serious · 3,338 with death outcome · 40% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Bendamustine Hydrochloride for Injection is an alkylating drug indicated for treatment of patients with: Chronic lymphocytic leukemia (CLL). Efficacy relative to first line therapies other than chlorambucil has not been established. ( 1.1 ) Indolent B-cell non-Hodgkin lymphoma (NHL) that has progressed during or within six months of treatment with rituximab or a rituximab-containing regimen.

FDA label, Indications and Usage

What it is

Bendamustine hydrochloride is an alkylating agent.

FDA label, Description section

Boxed warning

None in the current label

How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation. Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)? That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.

Causality screen of the 40 strongest signals

Labeled adverse reaction 1Labeled (related wording) 9Likely indication confounding 11Reporting / coding artifact 1Lab value / disease marker 4Not in label — unassessed 14
What the badges mean

Strongest disproportionality signals

Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 1,007 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show:
ReactionReportsPRR 95% CI · ROR · χ²/pEBGM EB05 · IC025Label screenSerious-only & strataTrial cross-check
Follicular lymphoma refractory22797.5
470.6–1,351.4ROR 798.6 · χ² 10,481 / p <1e-300
348.5 EB05 242.6 · IC025 +4.7
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=22 · 100% cliniciannot reported in cached trials
Marginal zone lymphoma recurrent16692.2
378.7–1,265.3ROR 693.0 · χ² 6,835 / p <1e-300
295.5 EB05 192.9 · IC025 +4.1
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=16not reported in cached trials
Follicular lymphoma recurrent11245.9
129.3–467.6ROR 246.1 · χ² 2,065 / p <1e-300
153.3 EB05 91.3 · IC025 +3.4
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=11not reported in cached trials
Splenic marginal zone lymphoma11230.5
121.6–437.0ROR 230.7 · χ² 1,954 / p <1e-300
147.2 EB05 87.7 · IC025 +3.3
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=11not reported in cached trials
Follicular lymphoma121225.1
185.8–272.7ROR 226.9 · χ² 22,924 / p <1e-300
187.2 EB05 160.8 · IC025 +6.5
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=117not reported in cached trials
Humoral immune defect52221.4
165.2–296.8ROR 222.2 · χ² 9,604 / p <1e-300
177.8 EB05 140.8 · IC025 +5.6
3/3 methods agree
Not in label — unassessedserious n=45 · 100% cliniciannot reported in cached trials
Blood immunoglobulin m abnormal14211.0
120.1–370.6ROR 211.2 · χ² 2,350 / p <1e-300
146.4 EB05 92.7 · IC025 +3.7
3/3 methods agree
Lab value / disease markerserious n=14not reported in cached trials
B-cell lymphoma recurrent70201.9
157.1–259.4ROR 202.8 · χ² 11,989 / p <1e-300
167.6 EB05 137.2 · IC025 +5.9
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=69 · 90% cliniciannot reported in cached trials
Mantle cell lymphoma recurrent55200.5
151.1–266.0ROR 201.2 · χ² 9,323 / p <1e-300
164.6 EB05 131.2 · IC025 +5.6
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=55 · 100% cliniciannot reported in cached trials
Fungal disease carrier13200.4
111.9–358.9ROR 200.6 · χ² 2,074 / p <1e-300
139.3 EB05 86.6 · IC025 +3.6
3/3 methods agree
Reporting / coding artifactserious n=13not reported in cached trials
B-cell lymphoma refractory10169.8
88.0–327.7ROR 169.9 · χ² 1,343 / p 2e-294
117.6 EB05 68.3 · IC025 +3.1
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=10not reported in cached trials
Lymphoma transformation38160.3
114.5–224.3ROR 160.7 · χ² 5,231 / p <1e-300
133.8 EB05 101.7 · IC025 +5.1
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=38 · 95% cliniciannot reported in cached trials
Blood immunoglobulin g abnormal16148.0
88.3–248.0ROR 148.1 · χ² 1,973 / p <1e-300
115.4 EB05 75.3 · IC025 +3.9
3/3 methods agree
Lab value / disease markerserious n=16not reported in cached trials
Endocarditis noninfective13131.1
74.2–231.7ROR 131.2 · χ² 1,413 / p <1e-300
102.0 EB05 63.5 · IC025 +3.5
3/3 methods agree
Not in label — unassessedserious n=13not reported in cached trials
Refractory cancer17115.7
70.5–189.9ROR 115.9 · χ² 1,676 / p <1e-300
95.5 EB05 63.1 · IC025 +3.9
3/3 methods agree
Not in label — unassessedserious n=17not reported in cached trials
Reticulocytopenia11111.8
60.4–206.7ROR 111.8 · χ² 1,015 / p 6e-223
88.0 EB05 52.4 · IC025 +3.2
3/3 methods agree
Not in label — unassessedserious n=11not reported in cached trials
Blood stem cell harvest failure11108.5
58.7–200.5ROR 108.6 · χ² 987 / p 8e-217
85.9 EB05 51.2 · IC025 +3.2
3/3 methods agree
Not in label — unassessedserious n=11not reported in cached trials
Mantle cell lymphoma10197.0
79.3–118.7ROR 97.7 · χ² 8,863 / p <1e-300
89.1 EB05 75.4 · IC025 +5.6
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=100 · ♀ 17% (drug 40%) · 96% cliniciannot reported in cached trials
Vaccine interaction2093.8
59.6–147.5ROR 93.9 · χ² 1,630 / p <1e-300
81.2 EB05 55.5 · IC025 +4.1
3/3 methods agree
Not in label — unassessedserious n=13 · 100% cliniciannot reported in cached trials
Human polyomavirus infection2980.4
55.3–116.9ROR 80.5 · χ² 2,070 / p <1e-300
72.4 EB05 52.9 · IC025 +4.4
3/3 methods agree
Not in label — unassessedserious n=29 · ♀ 0% (drug 40%) · 100% cliniciannot reported in cached trials
Breakthrough covid-191380.3
45.9–140.6ROR 80.4 · χ² 888 / p 2e-195
68.6 EB05 42.6 · IC025 +3.4
3/3 methods agree
Not in label — unassessedserious n=13not reported in cached trials
Primary amyloidosis1479.6
46.4–136.4ROR 79.6 · χ² 952 / p 2e-209
68.4 EB05 43.3 · IC025 +3.5
3/3 methods agree
Not in label — unassessedserious n=14not reported in cached trials
Marginal zone lymphoma1174.5
40.6–136.7ROR 74.6 · χ² 688 / p 7e-152
63.3 EB05 37.7 · IC025 +3.1
3/3 methods agree
Likely indication confounding
shares a disease stem with the indications wording
serious n=11not reported in cached trials
Candida pneumonia1670.6
42.7–116.7ROR 70.7 · χ² 978 / p 6e-215
62.4 EB05 40.7 · IC025 +3.6
3/3 methods agree
Not in label — unassessedserious n=16not reported in cached trials
Cystitis viral1867.4
42.0–108.2ROR 67.5 · χ² 1,059 / p 1e-232
60.3 EB05 40.4 · IC025 +3.8
3/3 methods agree
Not in label — unassessedserious n=18not reported in cached trials
Campylobacter infection3559.6
42.5–83.5ROR 59.7 · χ² 1,874 / p <1e-300
55.4 EB05 41.7 · IC025 +4.4
3/3 methods agree
Not in label — unassessedserious n=33 · 100% cliniciannot reported in cached trials
Progressive multifocal leukoencephalopathy32155.0
49.3–61.5ROR 56.2 · χ² 16,313 / p <1e-300
52.7 EB05 48.1 · IC025 +5.4
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 31.9 · 97% cliniciannot reported in cached trials
Blood lactate dehydrogenase abnormal2552.5
35.2–78.2ROR 52.6 · χ² 1,166 / p 9e-256
48.8 EB05 34.7 · IC025 +4.0
3/3 methods agree
Lab value / disease markerserious n=25 · 96% cliniciannot reported in cached trials
Campylobacter gastroenteritis2047.7
30.6–74.5ROR 47.8 · χ² 839 / p 9e-185
44.3 EB05 30.3 · IC025 +3.7
3/3 methods agree
Not in label — unassessedserious n=20 · 100% cliniciannot reported in cached trials
Bone marrow infiltration1347.4
27.3–82.4ROR 47.4 · χ² 526 / p 1e-116
43.1 EB05 26.8 · IC025 +3.2
3/3 methods agree
Not in label — unassessedserious n=13not reported in cached trials
Blood uric acid abnormal1345.2
26.0–78.5ROR 45.2 · χ² 501 / p 2e-111
41.3 EB05 25.7 · IC025 +3.1
3/3 methods agree
Lab value / disease markerserious n=13not reported in cached trials

Trial evidence (ClinicalTrials.gov)

✓ Trial adverse-event data found on ClinicalTrials.gov

Largest completed trials with posted results that list Bendamustine as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (0 of 40 signal terms matched).

Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.

Most frequently reported reactions

By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.

ReactionReportsPRR 95% CI · ROR · χ²/pEBGM EB05 · IC025Label screenSerious-only & strataTrial cross-check
Disease progression2,24226.3
25.3–27.4ROR 30.7 · χ² 53,895 / p <1e-300
25.9 EB05 25.0 · IC025 +4.6
3/3 methods agree
Reporting / coding artifactserious PRR 17.3 · 97% cliniciannot reported in cached trials
Off label use (used outside approved label)2,0373.2
3.1–3.3ROR 3.5 · χ² 3,200 / p <1e-300
3.2 EB05 3.1 · IC025 +1.6
3/3 methods agree
Reporting / coding artifactserious PRR 3.4 · 93% cliniciannot reported in cached trials
Neutropenia (low neutrophils (infection-fighting cells))1,16911.8
11.2–12.5ROR 12.7 · χ² 11,553 / p <1e-300
11.7 EB05 11.2 · IC025 +3.4
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 7.3 · 97% clinicianNCT01476787: 6/112 (5.4%) on Bendamustine (serious AE)
Pyrexia (fever)1,0474.1
3.9–4.4ROR 4.4 · χ² 2,507 / p <1e-300
4.1 EB05 3.9 · IC025 +1.9
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 3.0 · 94% clinicianNCT01476787: 1/112 (0.9%) on Bendamustine (serious AE)
Drug ineffective (drug did not work)9641.0
0.9–1.1ROR 1.0 · χ² 0 / p 0.453
1.0 EB05 0.9 · IC025 -0.1
PRR-only: not supported by EBGM or IC
Reporting / coding artifactserious PRR 1.7 · 94% cliniciannot reported in cached trials
Thrombocytopenia (low platelets)95011.7
11.0–12.4ROR 12.4 · χ² 9,236 / p <1e-300
11.6 EB05 11.0 · IC025 +3.4
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 7.1 · 97% clinicianNCT01476787: 3/507 (0.6%) on Bendamustine (serious AE)
Pneumonia (lung infection)8433.6
3.3–3.8ROR 3.7 · χ² 1,565 / p <1e-300
3.5 EB05 3.3 · IC025 +1.7
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 2.2 · 95% clinicianNCT01476787: 2/365 (0.5%) on Bendamustine (serious AE)
Febrile neutropenia79716.6
15.5–17.7ROR 17.4 · χ² 11,530 / p <1e-300
16.4 EB05 15.4 · IC025 +3.9
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 9.9 · 98% clinicianNCT01476787: 6/112 (5.4%) on Bendamustine (serious AE)
Anaemia (low red blood cells)7735.5
5.2–5.9ROR 5.8 · χ² 2,876 / p <1e-300
5.5 EB05 5.2 · IC025 +2.3
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 3.6 · 93% clinicianNCT01476787: 1/507 (0.2%) on Bendamustine (serious AE)
Covid-197445.7
5.4–6.2ROR 6.0 · χ² 2,919 / p <1e-300
5.7 EB05 5.4 · IC025 +2.4
3/3 methods agree
Not in label — unassessedserious PRR 5.8 · 97% cliniciannot reported in cached trials
Death7021.1
1.0–1.2ROR 1.1 · χ² 8 / p 0.003
1.1 EB05 1.0 · IC025 +0.0Outcome field, not a reactionserious PRR 0.7 · 94% clinicianNCT01476787: 1/365 (0.3%) on Bendamustine (serious AE)
Infection5775.5
5.0–5.9ROR 5.6 · χ² 2,104 / p <1e-300
5.4 EB05 5.1 · IC025 +2.3
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 4.1 · 95% clinicianNCT01476787: 1/507 (0.2%) on Bendamustine (serious AE)
Diarrhoea (diarrhea)5121.1
1.0–1.2ROR 1.1 · χ² 3 / p 0.036
1.1 EB05 1.0 · IC025 -0.0
PRR-only: not supported by EBGM or IC
Labeled adverse reaction
exact term
serious PRR 1.1 · 94% clinicianNCT01476787: 4/507 (0.8%) on Bendamustine (serious AE)
Sepsis (blood infection)4705.7
5.3–6.3ROR 5.9 · χ² 1,841 / p <1e-300
5.7 EB05 5.3 · IC025 +2.4
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 3.5 · 95% clinicianNCT01476787: 1/507 (0.2%) on Bendamustine (serious AE)
Pancytopenia (all blood cells low)45811.3
10.3–12.3ROR 11.6 · χ² 4,249 / p <1e-300
11.1 EB05 10.3 · IC025 +3.3
3/3 methods agree
Labeled adverse reaction
exact term
serious PRR 6.8 · 95% clinicianNCT01476787: 2/507 (0.4%) on Bendamustine (serious AE)

Unlabeled candidate signals

These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.

Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.

Common questions

What are the most reported side effects of Bendamustine?

In FDA FAERS, the most frequently co-reported reaction terms for Bendamustine are neutropenia, pyrexia, thrombocytopenia, pneumonia, febrile neutropenia, anaemia. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.

Does Bendamustine have an FDA boxed warning?

No. The FDA label retrieved for Bendamustine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Bendamustine causes these side effects?

No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.

Sources & methods

Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.