Effect of lapatinib on oral digoxin absorption in patients

Kevin M. Koch, Deborah A. Smith, Jeff Botbyl, Nikita Arya, Linda P. Briley, Leanne Cartee, Jane Holshouser White, Jennifer Beyer, Mohammed M. Dar, Hyun Choel Chung, Quincy Chu, Yung Jue Bang

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


The potential for an interaction between lapatinib and absorption of the P-glycoprotein (ABCB1) substrate digoxin at a therapeutic dose in breast cancer patients was characterized. Seventeen women with HER2-positive metastatic breast cancer received a single oral 0.5-mg dose of digoxin on days 1 and 9 and oral lapatinib 1500 mg once daily on days 2 through 9. Digoxin pharmacokinetic parameters were determined on day 1 (digoxin administration alone) and on day 9 (coadministration of lapatinib and digoxin), and parameters were compared to determine the effects of lapatinib on digoxin absorption. Concomitant medications that could affect ABCB1 were accounted for. Lapatinib 1500mg/day increased digoxin absorption approximately 80%, implicating lapatinib inhibition of intestinal ABCB1-mediated efflux. In summary, coadministration of lapatinib with narrow therapeutic index drugs that are substrates of ABCB1 should be undertaken with caution and dose adjustment should be considered.

Original languageEnglish
Pages (from-to)449-453
Number of pages5
JournalClinical Pharmacology in Drug Development
Issue number6
Publication statusPublished - 2015 Nov 1

Bibliographical note

Publisher Copyright:
© 2015, The American College of Clinical Pharmacology.

All Science Journal Classification (ASJC) codes

  • Pharmaceutical Science
  • Pharmacology (medical)


Dive into the research topics of 'Effect of lapatinib on oral digoxin absorption in patients'. Together they form a unique fingerprint.

Cite this