Digoxin and Lapatinib interaction
Digoxin and Lapatinib: the Lapatinib prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Lapatinib (TYKERB) label · effective 2026-01-27
These conditions include patients with hypokalemia or hypomagnesemia, with congenital long QT syndrome, patients taking antiarrhythmic medicines or other medicinal products with known risk for QT prolongation/ Torsades de Pointes, and cumulative high-dose anthracycline therapy.
Digoxin : Following coadministration of TYKERB and digoxin (P-gp substrate), systemic AUC of an oral digoxin dose increased approximately 2.8-fold.
Serum digoxin concentrations should be monitored prior to initiation of TYKERB and throughout coadministration.
If digoxin serum concentration is greater than 1.2 ng/mL, the digoxin dose should be reduced by half.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.