Key facts about Lapatinib
What dosages is Lapatinib available in?
Lapatinib is available as a 250 mg oral tablet.
What is Lapatinib used for?
Lapatinib is a tyrosine kinase inhibitor that is used to treat:
- HER2-positive metastatic breast cancer
- HR-positive, HER2-positive metastatic breast cancer
How does Lapatinib work?
Lapatinib is a tyrosine kinase inhibitor (TKI). It works by blocking the action of specific proteins called human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR). HER2 and EGFR are both found on normal and cancer cells, and they play a role in cell growth. In certain cancers, the cancer cells have more HER2 and EGFR proteins than normal cells. When these proteins are blocked by Lapatinib, cancer cells can’t grow and spread as well.
How do I take Lapatinib?
Lapatinib is dosed as follows:
- HER2-positive metastatic breast cancer: The typical dose is 5 tablets (total of 1,250 mg of Lapatinib) taken by mouth at one time every day
- HR-positive, HER2-positive metastatic breast cancer: The typical dose is 6 tablets (total of 1,500 mg of Lapatinib) taken by mouth at one time every day
Your dose might be different if you have liver problems.
Is it safe for me to take Lapatinib?
Lapatinib is a safe and effective treatment when used for FDA licensed indications. However, like all medications, they may give you unwanted side effects. You should always discuss potential side effects with your physician to ensure the medication is suitable and right for you.
Lapatinib Common Side Effects
Common side effects of Lapatinib:
- Diarrhea
- Rash
- Hand-foot syndrome
- Nausea
- Infection around the nails
- Vomiting
- Tiredness
- Lowered appetite
- Inflammation or reddening inside of the mouth
Lapatinib Serious Side Effects
Serious side effects are rare with Lapatinib. Contact your healthcare provider immediately if you experience any of the following.
- Severe diarrhea
- Liver problems: yellowing of skin or whites of your eyes, dark-colored urine, right upper stomach pain or discomfort, itchy skin
- Severe skin reactions: blisters on the skin, peeling skin, red skin, rash that keeps getting worse
Effects of other drugs, drug classes and over-the-counter products on Lapatinib
The following medications may interact with Lapatinib:
- Lapatinib is likely to increase exposure to concomitantly administered drugswhich are substrates of CYP3A4, or P-glycoprotein (ABCB1)
- Avoid strong CYP3A4 inhibitors. If unavoidable, consider dose reduction of Lapatinib in patients coadministered a strong CYP3A4 inhibitor
- Avoid strong CYP3A4 inducers. If unavoidable, consider gradual dose increase of Lapatinib in patients coadministered a strong CYP3A4 inducer
Who makes Lapatinib?
Various FDA-approved generic manufacturers
Is Lapatinib safe in pregnancy?
Lapatinib can harm your unborn baby. Your healthcare provider should check to see if you are pregnant before you start taking Lapatinib. You should use effective birth control
(contraception) during treatment with Lapatinib and for 1 week after the last dose of Lapatinib. Tell your healthcare
provider right away if you become pregnant during treatment with Lapatinib.
For males with female partners who are able to become pregnant:
- Use effective contraception during treatment with Lapatinib and for 1 week after the last dose.
- If your female partner becomes pregnant during treatment with Lapatinib, tell your healthcare provider right away.













