Lapatinib

86 interactions 6 explained in plain English

Also sold as: Tykerb Tykerb®

About Lapatinib

Lapatinib is used with capecitabine (Xeloda) to treat a certain type of advanced breast cancer in people who have already been treated with other chemotherapy medications. Lapatinib is also used with letrozole (Femara) to treat a certain type of breast cancer in postmenopausal women (women who have experienced a change… Read the full Lapatinib drug information page →

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Jun 30, 2026 · Editorial policy · Data sources

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

Most serious with: Colchicine Mefloquine Oxaliplatin Injection Hydroxychloroquine Asenapine Transdermal Patch Metronidazole Injection

1 Contraindicated 80 Major 5 Moderate

All (86) Contraindicated (1) Major (80) Moderate (5)

Contraindicated

Lapatinib Colchicine Colcrys Explained Increased colchicine exposure and an increased risk of colchicine toxicity Details

Major

Lapatinib Abametapir Explained Increased exposure of CYP3A4 substrate Details Lapatinib Amitriptyline Elavil Explained An increased risk of QT interval prolongation Details Lapatinib Sertraline Explained An increased risk of QT interval prolongation Details Lapatinib Buprenorphine Belbuca Explained An increased risk of QT interval prolongation Details Lapatinib Relugolix Orgovyx Explained Increased relugolix exposure and an increased risk of QT interval prolongation Details Lapatinib Amisulpride Injection Barhemsys Increased risk of serious ventricular arrhythmias such as torsades de pointes Details Lapatinib Arsenic Trioxide Trisenox An increased risk of QT interval prolongation Details Lapatinib Aripiprazole Injection Abilify An increased risk of QT interval prolongation Details Lapatinib Arsenic Trioxide Injection Trisenox An increased risk of QT interval prolongation Details Lapatinib Asenapine Transdermal Patch Secuado Increased risk of QT interval prolongation Details Lapatinib Azathioprine Azasan An increased risk of hepatotoxicity Details Lapatinib Azithromycin AzaSite An increased risk of QT interval prolongation Details Lapatinib Betrixaban Bevyxxa® Increased betrixaban exposure and increased risk of bleeding Details Lapatinib Afatinib Gilotrif Increased exposure of afatinib Details Lapatinib Alfuzosin UroXatral An increased risk of QT interval prolongation Details Lapatinib Anagrelide Agrylin Increased risk of QT interval prolongation Details Lapatinib Bedaquiline Sirturo Increased risk of QT interval prolongation Details Lapatinib Capmatinib Tabrecta Increased P-gp substrate exposure and an increased risk of increased adverse reactions Details Lapatinib Chloroquine Aralen® An increased risk of QT interval prolongation Details Lapatinib Cyclosporine Injection Atopica Increased cycloSPORINE exposure Details Lapatinib Cyclosporine Ophthalmic Cequa Increased cycloSPORINE exposure Details Lapatinib Dabigatran Pradaxa® Increased dabigatran exposure and an increased risk of bleeding Details Lapatinib Dabigatran Etexilate Increased dabigatran exposure and an increased risk of bleeding Details Lapatinib Dasatinib Phyrago An increased risk of QT interval prolongation Details Lapatinib Degarelix Injection Firmagon Increased risk of QT interval prolongation Details Lapatinib Deutetrabenazine Austedo An increased risk of QT interval prolongation Details Lapatinib Dexamethasone Injection Decadron Decreased lapatinib exposure or plasma concentrations Details Lapatinib Dexamethasone Ophthalmic Dexacidin® (as a combination product containing Dexamethasone, Neomycin, Polymyxin B) Decreased lapatinib exposure or plasma concentrations Details Lapatinib Digoxin Cardoxin® Increased exposure of digoxin Details Lapatinib Disopyramide Norpace An increased risk of QT interval prolongation Details Lapatinib Dofetilide Tikosyn Increased dofetilide plasma concentrations and an increased risk of QT interval prolongation Details Lapatinib Dolasetron Anzemet An increased risk of QT interval prolongation Details Lapatinib Dolasetron Injection Anzemet An increased risk of QT interval prolongation Details Lapatinib Doxorubicin Adriamycin Increased DOXOrubicin exposure and an increased risk of DOXOrubicin-related adverse reactions Details Lapatinib Encorafenib Braftovi Increased risk of QT interval prolongation Details Lapatinib Entrectinib Rozlytrek An increased risk of QT interval prolongation Details Lapatinib Finerenone Kerendia Increased finerenone exposure and an increased risk of finerenone-related adverse effects Details Lapatinib Flecainide Tambocor® An increased risk of QT interval prolongation Details Lapatinib Foscarnet Injection Foscavir Increased risk of QT interval prolongation Details

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Educational information only, not medical advice. Always confirm interactions with your pharmacist or prescriber before making any change to your medications.