Ixabepilone side effects: what 1,049 FDA adverse event reports show
Drug class
Microtubule inhibitor
Brand names
Ixempra
Who reports
1,049 reports · 82% serious · 240 with death outcome · 92% female
Used for
IXEMPRA is indicated in combination with capecitabine for the treatment of patients with metastatic or locally advanced breast cancer resistant to treatment with an anthracycline and a taxane, or whose cancer is taxane resistant and for whom further anthracycline therapy is contraindicated.
What it is
IXEMPRA (ixabepilone) is a microtubule inhibitor belonging to a class of antineoplastic agents, the epothilones and their analogs. The epothilones are isolated from the myxobacterium Sorangium cellulosum.
Boxed warning
TOXICITY IN PATIENTS WITH HEPATIC IMPAIRMENT IXEMPRA in combination with capecitabine is contraindicated in patients with AST or ALT >2.5 x ULN or bilirubin >1 x ULN due to increased risk of toxicity and neutropenia-related death [see Contraindications ( 4 ) and Warnings and Precautions ( 5.3 )].
Causality screen of the 21 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 adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- 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. 14 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 |
|---|---|---|---|---|---|---|
| Neutrophil count decreased | 67 | 33.1 26.3–41.8ROR 35.3 · χ² 2,055 / p <1e-300 | 32.8 EB05 26.7 · IC025 +4.3 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 26.7 | no trial data cached |
| Breast cancer metastatic | 15 | 28.0 16.9–46.3ROR 28.4 · χ² 363 / p 2e-81 | 27.1 EB05 17.4 · IC025 +3.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 16.1 | no trial data cached |
| Metastases to central nervous system | 13 | 20.3 11.8–34.9ROR 20.5 · χ² 220 / p 6e-50 | 19.5 EB05 11.7 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 14.5 | no trial data cached |
| Metastases to liver | 17 | 19.4 12.1–31.1ROR 19.7 · χ² 278 / p 8e-63 | 18.9 EB05 12.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 13.8 | no trial data cached |
| Mucosal inflammation | 25 | 19.2 13.0–28.3ROR 19.6 · χ² 413 / p 4e-92 | 18.9 EB05 13.3 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 14.4 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 21 | 18.0 11.8–27.4ROR 18.3 · χ² 320 / p 9e-72 | 17.6 EB05 11.9 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 13.6 | no trial data cached |
| Metastases to bone | 14 | 17.1 10.2–28.8ROR 17.3 · χ² 197 / p 6e-45 | 16.3 EB05 9.7 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 12.2 | no trial data cached |
| Small intestinal obstruction | 10 | 16.3 8.8–30.2ROR 16.4 · χ² 129 / p 4e-30 | 14.8 EB05 7.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 11.6 | no trial data cached |
| Hypocalcaemia (low calcium) | 15 | 15.9 9.6–26.3ROR 16.1 · χ² 195 / p 1e-44 | 15.1 EB05 9.1 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 11.9 | no trial data cached |
| Febrile neutropenia | 49 | 14.8 11.3–19.5ROR 15.5 · χ² 618 / p 9e-137 | 14.6 EB05 11.4 · IC025 +3.2 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 10.1 | no trial data cached |
| Hypomagnesaemia | 10 | 14.4 7.8–26.7ROR 14.5 · χ² 112 / p 2e-26 | 12.6 EB05 6.3 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 10.5 | no trial data cached |
| Hypokalaemia (low potassium) | 33 | 14.4 10.3–20.1ROR 14.8 · χ² 398 / p 7e-89 | 14.1 EB05 10.3 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.3 | no trial data cached |
| Malignant neoplasm progression | 70 | 13.7 11.0–17.2ROR 14.7 · χ² 818 / p 3e-180 | 13.6 EB05 11.1 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | serious PRR 9.9 | no trial data cached |
| White blood cell count decreased | 69 | 12.7 10.1–16.0ROR 13.5 · χ² 737 / p 2e-162 | 12.5 EB05 10.2 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 12.0 | no trial data cached |
| Neuropathy peripheral (nerve damage in hands/feet) | 52 | 11.0 8.4–14.3ROR 11.5 · χ² 465 / p 2e-103 | 10.7 EB05 8.3 · IC025 +2.9 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 6.1 | no trial data cached |
| Pleural effusion | 33 | 10.8 7.7–15.2ROR 11.2 · χ² 286 / p 2e-64 | 10.3 EB05 7.4 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.9 | no trial data cached |
| Bone pain | 30 | 10.2 7.2–14.6ROR 10.5 · χ² 241 / p 1e-54 | 9.6 EB05 6.8 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.5 | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 68 | 10.0 8.0–12.6ROR 10.7 · χ² 548 / p 2e-121 | 9.8 EB05 7.9 · IC025 +2.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 7.1 | no trial data cached |
| Disease progression | 45 | 7.6 5.7–10.2ROR 7.9 · χ² 254 / p 2e-57 | 7.2 EB05 5.6 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 5.0 | no trial data cached |
| Respiratory arrest | 10 | 7.2 3.9–13.3ROR 7.2 · χ² 47 / p 3e-12 | 5.6 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Circumstance or information capable of leading to medication error | 10 | 6.0 3.2–11.0ROR 6.0 · χ² 37 / p 8e-10 | 4.8 EB05 2.8 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | – | 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 |
|---|---|---|---|---|---|---|
| Malignant neoplasm progression | 70 | 13.7 11.0–17.2ROR 14.7 · χ² 818 / p 3e-180 | 13.6 EB05 11.1 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | serious PRR 9.9 | no trial data cached |
| White blood cell count decreased | 69 | 12.7 10.1–16.0ROR 13.5 · χ² 737 / p 2e-162 | 12.5 EB05 10.2 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 12.0 | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 68 | 10.0 8.0–12.6ROR 10.7 · χ² 548 / p 2e-121 | 9.8 EB05 7.9 · IC025 +2.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 7.1 | no trial data cached |
| Neutrophil count decreased | 67 | 33.1 26.3–41.8ROR 35.3 · χ² 2,055 / p <1e-300 | 32.8 EB05 26.7 · IC025 +4.3 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 26.7 | no trial data cached |
| Neuropathy peripheral (nerve damage in hands/feet) | 52 | 11.0 8.4–14.3ROR 11.5 · χ² 465 / p 2e-103 | 10.7 EB05 8.3 · IC025 +2.9 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 6.1 | no trial data cached |
| Febrile neutropenia | 49 | 14.8 11.3–19.5ROR 15.5 · χ² 618 / p 9e-137 | 14.6 EB05 11.4 · IC025 +3.2 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 10.1 | no trial data cached |
| Disease progression | 45 | 7.6 5.7–10.2ROR 7.9 · χ² 254 / p 2e-57 | 7.2 EB05 5.6 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 5.0 | no trial data cached |
| Pleural effusion | 33 | 10.8 7.7–15.2ROR 11.2 · χ² 286 / p 2e-64 | 10.3 EB05 7.4 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.9 | no trial data cached |
| Hypokalaemia (low potassium) | 33 | 14.4 10.3–20.1ROR 14.8 · χ² 398 / p 7e-89 | 14.1 EB05 10.3 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.3 | no trial data cached |
| Bone pain | 30 | 10.2 7.2–14.6ROR 10.5 · χ² 241 / p 1e-54 | 9.6 EB05 6.8 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.5 | no trial data cached |
| Mucosal inflammation | 25 | 19.2 13.0–28.3ROR 19.6 · χ² 413 / p 4e-92 | 18.9 EB05 13.3 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 14.4 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 21 | 18.0 11.8–27.4ROR 18.3 · χ² 320 / p 9e-72 | 17.6 EB05 11.9 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 13.6 | no trial data cached |
| Metastases to liver | 17 | 19.4 12.1–31.1ROR 19.7 · χ² 278 / p 8e-63 | 18.9 EB05 12.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 13.8 | no trial data cached |
| Hypocalcaemia (low calcium) | 15 | 15.9 9.6–26.3ROR 16.1 · χ² 195 / p 1e-44 | 15.1 EB05 9.1 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 11.9 | no trial data cached |
| Breast cancer metastatic | 15 | 28.0 16.9–46.3ROR 28.4 · χ² 363 / p 2e-81 | 27.1 EB05 17.4 · IC025 +3.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 16.1 | 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.
- Palmar-plantar erythrodysaesthesia syndrome — n=21, PRR 18.0
- Pleural effusion — n=33, PRR 10.8
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 Ixabepilone?
In FDA FAERS, the most frequently co-reported reaction terms for Ixabepilone are white blood cell count decreased, neutropenia, neutrophil count decreased, neuropathy peripheral, febrile neutropenia, pleural effusion. 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 Ixabepilone have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: TOXICITY IN PATIENTS WITH HEPATIC IMPAIRMENT IXEMPRA in combination with capecitabine is contraindicated in patients with AST or ALT >2.5 x ULN or bilirubin >1 x ULN due to increased risk of toxicity and neutropenia-related death [see Contraindications ( 4 ) and Warnings and Precautions ( 5.3 )].
Do FAERS signals prove that Ixabepilone 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 241f0b1e-8b95-470d-876f-bf1804daaf18, effective 20251204; matched on
openfda.generic_name.exact:"IXABEPILONE") - 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, 35 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.