lapatinib (Tykerb)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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What is lapatinib, and how does it work (mechanism of action)?

Lapatinib is an oral medication used for treating breast cancer. Lapatinib is classified as a kinase inhibitor. Kinase inhibitors include

Kinase inhibitors prevent the growth of tumors by reducing the action of proteins that control cell division, growth and survival. These proteins usually are present in larger quantities or are more active in cancer cells. By reducing the activity of these proteins, growth and survival of cancer cells are reduced. The FDA approved lapatinib in March, 2007.

What brand names are available for lapatinib?


Is lapatinib available as a generic drug?


Do I need a prescription for lapatinib?


What are the side effects of lapatinib?

Common side effects include:

Other side effects and adverse reactions include

  • Lapatinib may cause a type of abnormal heart rhythm called prolongation of the QT interval. Prolongation of the QT interval may lead to sudden death. ECGs should be obtained prior to starting lapatinib. Low potassium or low magnesium may increase the risk of QT prolongation. Therefore, low potassium and low magnesium should be corrected prior to starting treatment. Food and/or drugs that reduce the breakdown of lapatinib in the liver and/or medicinal products that prolong the QT interval may increase the risk of QT prolongation and should not be combined with lapatinib.

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What is the dosage for lapatinib?

  • The recommended dose of lapatinib for advanced or metastatic breast cancer is 1,250 mg (5 tablets) orally once daily on days 1-21 in combination with capecitabine 2,000 mg/m2/day on days 1-14 in a repeating 21-day cycle.
  • The recommended dose of lapatinib for hormone receptor-positive, HER2- positive metastatic breast cancer is 1,500 mg (6 tablets) orally once daily in combination with letrozole 2.5 mg once daily.
  • Lapatinib should be taken at least one hour before or one hour after a meal.

Which drugs or supplements interact with lapatinib?

  • The blood concentration of lapatinib may be increased by several drugs (for example, ketoconazole [Nizoral, Extina, Xolegel, Kuric]) that reduce its break down by the liver.
  • Certain drugs (for example, carbamazepine [Tegretol, Tegretol XR , Equetro, Carbatrol, Epitol, Teril]) decrease the concentration of lapatinib resulting in decreased blood levels and possibly reduced effect.
  • Lapatinib may increase blood levels of midazolam, digoxin (Lanoxin), and paclitaxol by reducing their breakdown in the liver.
  • Food increases the blood concentration of lapatinib. Therefore, lapatinib should be taken on an empty stomach, at least 1 hour before and after eating food.

Is lapatinib safe to take if I'm pregnant or breastfeeding?

Lapatinib is harmful to the fetus and should not be used during pregnancy.

It is not known whether lapatinib is excreted in human milk. Some related drugs are excreted in breast milk. To avoid any risk to the infant, nursing mothers should consider discontinuing nursing or lapatinib.

What else should I know about lapatinib?

What preparations of lapatinib are available?

Tablets: 250 mg

How should I keep lapatinib stored?

Lapatinib should be stored at room temperature between 15 C and 30 C (59 F and 86 F).

REFERENCE: FDA Prescribing Information

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Reviewed on 11/5/2015
REFERENCE: FDA Prescribing Information

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