Drug · FAERS side-effect profile with label screen
Tucatinib side effects: what 6,932 FDA adverse event reports show
Brand names
Tukysa
openFDA label
Who reports
6,932 reports · 65% serious · 708 with death outcome · 95% female
openFDA FAERS counts, all years, deduplication not applied
Used for
TUKYSA is a kinase inhibitor indicated: • in combination with trastuzumab and capecitabine for treatment of adult patients with advanced unresectable or metastatic HER2-positive breast cancer, including patients with brain metastases, who have received one or more prior anti-HER2-based regimens in the metastatic setting.
FDA label, Indications and Usage
What it is
Tucatinib is a kinase inhibitor.
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 8Labeled (related wording) 1Likely indication confounding 2Reporting / coding artifact 4Lab value / disease marker 4Not in label — unassessed 21
What the badges mean
- 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.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- 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. 228 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Metastases to central nervous system | 300 | 72.5 64.8–81.1ROR 75.8 · χ² 20,605 / p <1e-300 | 70.5 EB05 64.1 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious PRR 60.5 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 401 | 52.8 47.9–58.1ROR 55.9 · χ² 19,979 / p <1e-300 | 51.7 EB05 47.6 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious PRR 39.9 | no trial data cached |
| Breast cancer metastatic | 113 | 32.2 26.8–38.7ROR 32.7 · χ² 3,350 / p <1e-300 | 31.7 EB05 27.1 · IC025 +4.5 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 28.7 | no trial data cached |
| Hyperbilirubinaemia | 102 | 30.2 24.9–36.7ROR 30.7 · χ² 2,827 / p <1e-300 | 29.8 EB05 25.3 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious PRR 26.7 · 91% clinician | no trial data cached |
| Hospice care | 95 | 29.5 24.1–36.0ROR 29.8 · χ² 2,559 / p <1e-300 | 29.0 EB05 24.4 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 21.8 | no trial data cached |
| Brain oedema | 102 | 24.6 20.3–29.9ROR 25.0 · χ² 2,271 / p <1e-300 | 24.3 EB05 20.6 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 20.9 | no trial data cached |
| Hepatic cytolysis | 89 | 22.2 18.0–27.3ROR 22.5 · χ² 1,767 / p <1e-300 | 21.9 EB05 18.4 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 19.6 · 100% clinician | no trial data cached |
| Neoplasm progression | 252 | 21.9 19.4–24.7ROR 22.7 · χ² 4,969 / p <1e-300 | 21.7 EB05 19.5 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 15.9 | no trial data cached |
| Brain neoplasm | 59 | 19.5 15.1–25.2ROR 19.7 · χ² 1,013 / p 1e-222 | 19.3 EB05 15.5 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 15.8 · 71% consumer | no trial data cached |
| Skin fissures | 108 | 17.4 14.4–21.0ROR 17.7 · χ² 1,645 / p <1e-300 | 17.2 EB05 14.7 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=80 | no trial data cached |
| Metastases to lung | 61 | 16.1 12.5–20.6ROR 16.2 · χ² 843 / p 1e-185 | 15.9 EB05 12.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 13.9 | no trial data cached |
| Blood bilirubin increased | 128 | 14.4 12.1–17.1ROR 14.6 · χ² 1,572 / p <1e-300 | 14.2 EB05 12.3 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.7 | no trial data cached |
| Malignant neoplasm progression | 440 | 13.1 12.0–14.4ROR 13.9 · χ² 4,916 / p <1e-300 | 13.0 EB05 12.1 · IC025 +3.5 3/3 methods agree | Reporting / coding artifact | serious PRR 11.7 | no trial data cached |
| Candida infection (yeast infection) | 71 | 12.9 10.2–16.3ROR 13.0 · χ² 766 / p 5e-169 | 12.7 EB05 10.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 15.0 | no trial data cached |
| Liver function test increased | 89 | 12.7 10.3–15.6ROR 12.8 · χ² 942 / p 3e-207 | 12.5 EB05 10.4 · IC025 +3.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.6 | no trial data cached |
| Ejection fraction decreased | 63 | 12.3 9.6–15.7ROR 12.4 · χ² 640 / p 2e-141 | 12.0 EB05 9.6 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious PRR 10.3 · 92% clinician | no trial data cached |
| Metastases to bone | 64 | 11.9 9.3–15.2ROR 12.0 · χ² 625 / p 4e-138 | 11.6 EB05 9.3 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 10.3 | no trial data cached |
| Blood potassium decreased | 100 | 10.1 8.3–12.3ROR 10.2 · χ² 808 / p 6e-178 | 9.9 EB05 8.3 · IC025 +2.9 3/3 methods agree | Lab value / disease marker | serious PRR 7.7 | no trial data cached |
| Metastases to liver | 52 | 9.0 6.9–11.8ROR 9.1 · χ² 361 / p 1e-80 | 8.6 EB05 6.7 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 7.9 | no trial data cached |
| Hepatotoxicity (liver damage) | 65 | 8.9 7.0–11.3ROR 9.0 · χ² 447 / p 2e-99 | 8.5 EB05 6.9 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.9 · 95% clinician | no trial data cached |
| Stomatitis (mouth sores) | 177 | 8.8 7.6–10.2ROR 9.1 · χ² 1,224 / p 2e-268 | 8.7 EB05 7.7 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.8 | no trial data cached |
| Central nervous system lesion | 39 | 8.6 6.3–11.7ROR 8.6 · χ² 252 / p 5e-57 | 8.0 EB05 6.0 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 7.7 | no trial data cached |
| Diarrhoea (diarrhea) | 1,766 | 8.3 8.0–8.7ROR 10.8 · χ² 11,704 / p <1e-300 | 8.3 EB05 8.0 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.8 | no trial data cached |
| Skin discolouration | 124 | 8.2 6.9–9.7ROR 8.3 · χ² 774 / p 1e-170 | 8.0 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 | no trial data cached |
| Disease progression | 298 | 7.7 6.9–8.6ROR 8.0 · χ² 1,725 / p <1e-300 | 7.6 EB05 6.9 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 4.7 | no trial data cached |
| Epilepsy | 74 | 7.4 5.9–9.2ROR 7.4 · χ² 399 / p 4e-89 | 7.1 EB05 5.8 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 · 96% clinician | no trial data cached |
| Hepatic enzyme increased | 160 | 7.1 6.1–8.3ROR 7.3 · χ² 839 / p 1e-184 | 7.0 EB05 6.1 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.1 | no trial data cached |
| Product dose omission in error | 61 | 6.9 5.4–8.8ROR 6.9 · χ² 301 / p 1e-67 | 6.6 EB05 5.3 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 15.4 · 70% consumer | no trial data cached |
| Neuropathy peripheral (nerve damage in hands/feet) | 208 | 6.7 5.8–7.6ROR 6.8 · χ² 999 / p 2e-219 | 6.6 EB05 5.9 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.9 | no trial data cached |
| Taste disorder | 43 | 6.5 4.8–8.8ROR 6.5 · χ² 195 / p 2e-44 | 6.1 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.5 | no trial data cached |
| Pneumonitis | 57 | 6.4 4.9–8.3ROR 6.4 · χ² 253 / p 2e-57 | 6.1 EB05 4.9 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 | no trial data cached |
| Blood calcium decreased | 23 | 6.2 4.1–9.3ROR 6.2 · χ² 95 / p 1e-22 | 5.5 EB05 3.9 · IC025 +1.8 3/3 methods agree | Lab value / disease marker | serious PRR 5.4 | no trial data cached |
| Unevaluable event | 153 | 6.1 5.2–7.2ROR 6.2 · χ² 652 / p 4e-144 | 6.0 EB05 5.3 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 5.3 | no trial data cached |
| Dehydration | 269 | 6.1 5.4–6.9ROR 6.3 · χ² 1,150 / p 3e-252 | 6.0 EB05 5.5 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 | no trial data cached |
| Ventricular fibrillation | 22 | 6.0 3.9–9.1ROR 6.0 · χ² 86 / p 8e-21 | 5.4 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 · 100% clinician | no trial data cached |
| Hypokalaemia (low potassium) | 90 | 5.9 4.8–7.3ROR 6.0 · χ² 365 / p 1e-81 | 5.8 EB05 4.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Red blood cell count decreased | 56 | 5.9 4.6–7.7ROR 6.0 · χ² 224 / p 5e-51 | 5.7 EB05 4.5 · IC025 +2.1 3/3 methods agree | Lab value / disease marker | serious PRR 4.3 · 73% consumer | no trial data cached |
| Cholestasis (bile flow blockage) | 33 | 5.2 3.7–7.4ROR 5.3 · χ² 109 / p 9e-26 | 4.9 EB05 3.6 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 · 97% clinician | no trial data cached |
| Brain fog | 25 | 5.2 3.5–7.7ROR 5.2 · χ² 80 / p 2e-19 | 4.8 EB05 3.4 · IC025 +1.6 3/3 methods agree | Likely indication confounding term in indications | serious PRR 3.2 · 84% consumer | no trial data cached |
| Transaminases increased | 37 | 5.0 3.7–7.0ROR 5.1 · χ² 116 / p 2e-27 | 4.8 EB05 3.6 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.7 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
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 |
|---|---|---|---|---|---|---|
| Diarrhoea (diarrhea) | 1,766 | 8.3 8.0–8.7ROR 10.8 · χ² 11,704 / p <1e-300 | 8.3 EB05 8.0 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.8 | no trial data cached |
| Fatigue (tiredness) | 962 | 3.7 3.5–4.0ROR 4.2 · χ² 2,009 / p <1e-300 | 3.7 EB05 3.5 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.3 | no trial data cached |
| Nausea | 922 | 3.5 3.3–3.8ROR 3.9 · χ² 1,740 / p <1e-300 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 | no trial data cached |
| Vomiting | 519 | 3.4 3.1–3.6ROR 3.5 · χ² 872 / p 5e-192 | 3.3 EB05 3.1 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.9 | no trial data cached |
| Off label use (used outside approved label) | 474 | 1.7 1.5–1.8ROR 1.7 · χ² 127 / p 1e-29 | 1.7 EB05 1.5 · IC025 +0.6 | Reporting / coding artifact | serious PRR 1.8 | no trial data cached |
| Death | 456 | 1.6 1.5–1.8ROR 1.6 · χ² 107 / p 2e-25 | 1.6 EB05 1.5 · IC025 +0.5 | Outcome field, not a reaction | serious PRR 1.4 | no trial data cached |
| Malignant neoplasm progression | 440 | 13.1 12.0–14.4ROR 13.9 · χ² 4,916 / p <1e-300 | 13.0 EB05 12.1 · IC025 +3.5 3/3 methods agree | Reporting / coding artifact | serious PRR 11.7 | no trial data cached |
| Palmar-plantar erythrodysaesthesia syndrome | 401 | 52.8 47.9–58.1ROR 55.9 · χ² 19,979 / p <1e-300 | 51.7 EB05 47.6 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious PRR 39.9 | no trial data cached |
| Product dose omission issue | 377 | 4.0 3.6–4.4ROR 4.2 · χ² 859 / p 4e-189 | 4.0 EB05 3.7 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 7.7 | no trial data cached |
| Asthenia (weakness) | 366 | 2.9 2.7–3.3ROR 3.1 · χ² 477 / p 6e-106 | 2.9 EB05 2.7 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 2.7 | no trial data cached |
| Decreased appetite (loss of appetite) | 314 | 4.1 3.7–4.6ROR 4.3 · χ² 742 / p 1e-163 | 4.1 EB05 3.7 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.6 | no trial data cached |
| Metastases to central nervous system | 300 | 72.5 64.8–81.1ROR 75.8 · χ² 20,605 / p <1e-300 | 70.5 EB05 64.1 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious PRR 60.5 | no trial data cached |
| Disease progression | 298 | 7.7 6.9–8.6ROR 8.0 · χ² 1,725 / p <1e-300 | 7.6 EB05 6.9 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 4.7 | no trial data cached |
| Dehydration | 269 | 6.1 5.4–6.9ROR 6.3 · χ² 1,150 / p 3e-252 | 6.0 EB05 5.5 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 | no trial data cached |
| Neoplasm progression | 252 | 21.9 19.4–24.7ROR 22.7 · χ² 4,969 / p <1e-300 | 21.7 EB05 19.5 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 15.9 | 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.
- Metastases to central nervous system — n=300, PRR 72.5
- Palmar-plantar erythrodysaesthesia syndrome — n=401, PRR 52.8
- Hyperbilirubinaemia — n=102, PRR 30.2
- Hospice care — n=95, PRR 29.5
- Brain oedema — n=102, PRR 24.6
- Hepatic cytolysis — n=89, PRR 22.2
- Neoplasm progression — n=252, PRR 21.9
- Brain neoplasm — n=59, PRR 19.5
- Skin fissures — n=108, PRR 17.4
- Metastases to lung — n=61, PRR 16.1
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 Tucatinib?
In FDA FAERS, the most frequently co-reported reaction terms for Tucatinib are diarrhoea, fatigue, nausea, vomiting, palmar-plantar erythrodysaesthesia syndrome, asthenia. 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 Tucatinib have an FDA boxed warning?
No. The FDA label retrieved for Tucatinib has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Tucatinib 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 f27eb1b9-b7fc-424e-988f-84dd7bb195a3, effective 20241104; matched on
openfda.generic_name.exact:"TUCATINIB") - 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, 268 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.