Mitomycin side effects: what 3,418 FDA adverse event reports show
Who reports
3,418 reports · 78% serious · 392 with death outcome · 50% female
Used for
Mitomycin for Injection, USP is not recommended as single-agent, primary therapy. It has been shown to be useful in the therapy of disseminated adenocarcinoma of the stomach or pancreas in proven combinations with other approved chemotherapeutic agents and as palliative treatment when other modalities have failed. Mitomycin is not recommended to replace appropriate surgery and/or radiotherapy.
What it is
DESCRIPTION Mitomycin, USP (also known as mitomycin and/or mitomycin-C) is an antibiotic isolated from the broth of Streptomyces caespitosus which has been shown to have antitumor activity. The compound is heat stable, has a high melting point, and is freely soluble in organic solvents.
Boxed warning
Mitomycin should be administered under the supervision of a qualified physician experienced in the use of cancer chemotherapeutic agents. Appropriate management of therapy and complications is possible only when adequate diagnostic and treatment facilities are readily available.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
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. 66 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Flank pain | 44 | 29.0 21.6–38.9ROR 29.3 · χ² 1,156 / p 1e-253 | 28.5 EB05 22.1 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 | no trial data cached |
| Dysuria (painful urination) | 100 | 16.7 13.8–20.3ROR 17.2 · χ² 1,458 / p <1e-300 | 16.6 EB05 14.0 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 8.7 | no trial data cached |
| Thrombotic microangiopathy | 24 | 15.2 10.2–22.7ROR 15.3 · χ² 304 / p 2e-68 | 14.8 EB05 10.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 · ♀ 75% (drug 50%) · 96% clinician | no trial data cached |
| Haematotoxicity | 21 | 13.9 9.1–21.3ROR 14.0 · χ² 239 / p 4e-54 | 13.3 EB05 8.7 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 9.5 · 95% clinician | no trial data cached |
| Mucosal inflammation | 58 | 13.7 10.6–17.7ROR 13.9 · χ² 668 / p 1e-147 | 13.5 EB05 10.7 · IC025 +3.2 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 10.5 · 92% clinician | no trial data cached |
| Metastases to liver | 39 | 13.7 10.0–18.7ROR 13.8 · χ² 445 / p 5e-99 | 13.4 EB05 10.0 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 10.1 | no trial data cached |
| Haematuria (blood in urine) | 69 | 12.4 9.8–15.6ROR 12.6 · χ² 709 / p 2e-156 | 12.2 EB05 9.9 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Pancytopenia (all blood cells low) | 103 | 11.4 9.4–13.7ROR 11.7 · χ² 963 / p 8e-212 | 11.2 EB05 9.4 · IC025 +3.1 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 8.3 | no trial data cached |
| Micturition urgency | 20 | 10.8 7.0–16.8ROR 10.9 · χ² 169 / p 7e-39 | 9.8 EB05 6.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.2 | no trial data cached |
| Metastases to central nervous system | 21 | 10.1 6.6–15.4ROR 10.1 · χ² 162 / p 2e-37 | 9.1 EB05 6.0 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.5 | no trial data cached |
| Metastases to lung | 18 | 9.6 6.0–15.2ROR 9.6 · χ² 130 / p 2e-30 | 8.4 EB05 5.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Leukopenia (low white blood cells) | 77 | 9.5 7.6–11.8ROR 9.7 · χ² 576 / p 1e-127 | 9.2 EB05 7.5 · IC025 +2.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 6.9 · 91% clinician | no trial data cached |
| Ileus | 18 | 9.0 5.7–14.2ROR 9.0 · χ² 120 / p 4e-28 | 7.8 EB05 5.0 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Urosepsis | 13 | 8.7 5.0–14.9ROR 8.7 · χ² 81 / p 1e-19 | 7.1 EB05 4.3 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Bone marrow failure | 28 | 8.4 5.8–12.2ROR 8.5 · χ² 175 / p 3e-40 | 7.7 EB05 5.5 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.2 · 93% clinician | no trial data cached |
| Post procedural complication | 26 | 8.3 5.7–12.2ROR 8.4 · χ² 160 / p 7e-37 | 7.5 EB05 5.3 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 3.6 | no trial data cached |
| Uveitis | 16 | 7.3 4.5–11.9ROR 7.3 · χ² 80 / p 2e-19 | 6.2 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 | no trial data cached |
| Myelodysplastic syndrome | 17 | 7.2 4.5–11.6ROR 7.2 · χ² 85 / p 2e-20 | 6.2 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 | no trial data cached |
| Pollakiuria (frequent urination) | 48 | 7.1 5.3–9.4ROR 7.2 · χ² 245 / p 2e-55 | 6.7 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · ♀ 26% (drug 50%) | no trial data cached |
| Renal pain | 12 | 7.0 4.0–12.3ROR 7.0 · χ² 56 / p 5e-14 | 5.7 EB05 3.4 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.8 | no trial data cached |
| Cardiogenic shock | 16 | 6.9 4.2–11.2ROR 6.9 · χ² 75 / p 3e-18 | 5.9 EB05 3.8 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 26 | 6.8 4.7–10.0ROR 6.9 · χ² 124 / p 5e-29 | 6.2 EB05 4.4 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 · 92% clinician | no trial data cached |
| Pulmonary arterial hypertension | 16 | 6.7 4.1–11.0ROR 6.8 · χ² 73 / p 8e-18 | 5.8 EB05 3.7 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.1 | no trial data cached |
| Febrile neutropenia | 72 | 6.7 5.3–8.4ROR 6.8 · χ² 343 / p 9e-77 | 6.4 EB05 5.3 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 · ♀ 71% (drug 50%) · 97% clinician | no trial data cached |
| Hepatic failure | 32 | 6.5 4.6–9.2ROR 6.6 · χ² 144 / p 2e-33 | 6.0 EB05 4.4 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 · 93% clinician | no trial data cached |
| Visual acuity reduced | 34 | 6.2 4.5–8.7ROR 6.3 · χ² 144 / p 2e-33 | 5.8 EB05 4.3 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Thrombocytopenia (low platelets) | 110 | 6.1 5.0–7.3ROR 6.2 · χ² 461 / p 1e-102 | 5.9 EB05 5.0 · IC025 +2.2 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.5 | no trial data cached |
| Obstructive airways disorder | 11 | 6.1 3.4–10.9ROR 6.1 · χ² 41 / p 6e-11 | 4.9 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Metastases to bone | 16 | 6.0 3.7–9.8ROR 6.0 · χ² 62 / p 2e-15 | 5.2 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Bacterial infection | 18 | 6.0 3.8–9.4ROR 6.0 · χ² 69 / p 4e-17 | 5.2 EB05 3.5 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Dermatitis | 20 | 5.9 3.8–9.2ROR 6.0 · χ² 77 / p 8e-19 | 5.3 EB05 3.6 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 | no trial data cached |
| Urinary retention | 32 | 5.9 4.2–8.3ROR 5.9 · χ² 126 / p 2e-29 | 5.5 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Therapy interrupted | 62 | 5.5 4.3–7.1ROR 5.6 · χ² 225 / p 3e-51 | 5.3 EB05 4.3 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 2.8 | no trial data cached |
| Interstitial lung disease | 42 | 5.3 4.0–7.2ROR 5.4 · χ² 144 / p 2e-33 | 5.1 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Disease progression | 100 | 5.2 4.3–6.3ROR 5.3 · χ² 337 / p 1e-75 | 5.1 EB05 4.3 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 96% clinician | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 108 | 4.9 4.1–5.9ROR 5.0 · χ² 333 / p 1e-74 | 4.8 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 93% clinician | no trial data cached |
| Therapy partial responder | 12 | 4.9 2.8–8.6ROR 4.9 · χ² 33 / p 4e-9 | 4.2 EB05 2.6 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 2.2 | no trial data cached |
| Cystitis | 25 | 4.8 3.2–7.1ROR 4.8 · χ² 72 / p 1e-17 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Incorrect route of drug administration | 28 | 4.7 3.3–6.9ROR 4.8 · χ² 79 / p 3e-19 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 16.8 · 93% clinician | no trial data cached |
| Hepatic steatosis | 14 | 4.6 2.7–7.8ROR 4.6 · χ² 36 / p 9e-10 | 4.1 EB05 2.6 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Thrombocytopenia (low platelets) | 110 | 6.1 5.0–7.3ROR 6.2 · χ² 461 / p 1e-102 | 5.9 EB05 5.0 · IC025 +2.2 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.5 | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 108 | 4.9 4.1–5.9ROR 5.0 · χ² 333 / p 1e-74 | 4.8 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 93% clinician | no trial data cached |
| Pancytopenia (all blood cells low) | 103 | 11.4 9.4–13.7ROR 11.7 · χ² 963 / p 8e-212 | 11.2 EB05 9.4 · IC025 +3.1 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 8.3 | no trial data cached |
| Disease progression | 100 | 5.2 4.3–6.3ROR 5.3 · χ² 337 / p 1e-75 | 5.1 EB05 4.3 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 96% clinician | no trial data cached |
| Dysuria (painful urination) | 100 | 16.7 13.8–20.3ROR 17.2 · χ² 1,458 / p <1e-300 | 16.6 EB05 14.0 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 8.7 | no trial data cached |
| Leukopenia (low white blood cells) | 77 | 9.5 7.6–11.8ROR 9.7 · χ² 576 / p 1e-127 | 9.2 EB05 7.5 · IC025 +2.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 6.9 · 91% clinician | no trial data cached |
| Febrile neutropenia | 72 | 6.7 5.3–8.4ROR 6.8 · χ² 343 / p 9e-77 | 6.4 EB05 5.3 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 · ♀ 71% (drug 50%) · 97% clinician | no trial data cached |
| Haematuria (blood in urine) | 69 | 12.4 9.8–15.6ROR 12.6 · χ² 709 / p 2e-156 | 12.2 EB05 9.9 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Therapy interrupted | 62 | 5.5 4.3–7.1ROR 5.6 · χ² 225 / p 3e-51 | 5.3 EB05 4.3 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 2.8 | no trial data cached |
| Malignant neoplasm progression | 61 | 3.7 2.9–4.7ROR 3.7 · χ² 117 / p 2e-27 | 3.6 EB05 2.9 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious PRR 2.7 · ♀ 71% (drug 50%) | no trial data cached |
| Mucosal inflammation | 58 | 13.7 10.6–17.7ROR 13.9 · χ² 668 / p 1e-147 | 13.5 EB05 10.7 · IC025 +3.2 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 10.5 · 92% clinician | no trial data cached |
| Adverse event | 48 | 3.2 2.4–4.2ROR 3.2 · χ² 71 / p 2e-17 | 3.1 EB05 2.4 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 3.4 | no trial data cached |
| Pollakiuria (frequent urination) | 48 | 7.1 5.3–9.4ROR 7.2 · χ² 245 / p 2e-55 | 6.7 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 · ♀ 26% (drug 50%) | no trial data cached |
| Flank pain | 44 | 29.0 21.6–38.9ROR 29.3 · χ² 1,156 / p 1e-253 | 28.5 EB05 22.1 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 | no trial data cached |
| White blood cell count decreased | 42 | 2.4 1.8–3.2ROR 2.4 · χ² 32 / p 7e-9 | 2.3 EB05 1.8 · IC025 +0.7 | Labeled — boxed warning synonym match | serious PRR 2.1 · 90% clinician | no trial data cached |
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.
- Flank pain — n=44, PRR 29.0
- Dysuria — n=100, PRR 16.7
- Thrombotic microangiopathy — n=24, PRR 15.2
- Haematotoxicity — n=21, PRR 13.9
- Metastases to liver — n=39, PRR 13.7
- Haematuria — n=69, PRR 12.4
- Micturition urgency — n=20, PRR 10.8
- Metastases to central nervous system — n=21, PRR 10.1
- Pollakiuria — n=48, PRR 7.1
- Palmar-plantar erythrodysaesthesia syndrome — n=26, PRR 6.8
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 Mitomycin?
In FDA FAERS, the most frequently co-reported reaction terms for Mitomycin are thrombocytopenia, neutropenia, pancytopenia, dysuria, leukopenia, febrile neutropenia. 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 Mitomycin have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: Mitomycin should be administered under the supervision of a qualified physician experienced in the use of cancer chemotherapeutic agents. Appropriate management of therapy and complications is possible only when adequate diagnostic and treatment facilities are readily available.
Do FAERS signals prove that Mitomycin 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
- FDA label via openFDA (set ID 2ecd0f9c-0980-4ac5-bd1b-0a0aee799b6f, effective 20230605; matched on
openfda.generic_name.exact:"MITOMYCIN") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 106 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
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.