Lapatinib

Generic name: Lapatinib
Brand names: Tykerb
Dosage form: oral tablet (250 mg)

Usage of Lapatinib

Lapatinib is used to treat advanced hormone-related breast cancer that has progressed or spread after treatment with other cancer medicines.

Lapatinib is used for this condition only if your tumor tests positive for a protein called human epidermal growth factor receptor 2 (HER2). HER2 protein can speed the growth of cancer cells.

In postmenopausal women, lapatinib is given in combination with a hormonal medicine called Letrozole (Femara). In others, lapatinib is given together with a cancer medicine called Capecitabine (Xeloda).

Lapatinib may also be used for purposes not listed in this medication guide.

Lapatinib side effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Lapatinib can cause severe or fatal liver problems. Call your doctor right away if you have: upper stomach pain, itching, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Also call your doctor at once if you have:

fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);

severe or ongoing diarrhea; or

new or worsening cough, wheezing, chest pain, feeling short of breath.

Common side effects of lapatinib may include:

indigestion, loss of appetite;

nausea, vomiting, diarrhea;

rash, itching, dry skin, acne;

pain or redness on the palms of your hands or the soles of your feet;

problems with your fingernails or toenails;

feeling weak or tired;

nosebleeds, mouth sores;

thinning hair; or

headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Before taking Lapatinib

You should not use lapatinib if you are allergic to it.

Tell your doctor if you have ever had:

heart disease;

liver disease (lapatinib can cause severe or fatal liver problems);

an electrolyte imbalance (such as low levels of potassium or magnesium in your blood); or

long QT syndrome (in you or a family member).

You may need to have a negative pregnancy test before starting this treatment.

Both men and women using lapatinib should use effective birth control to prevent pregnancy. Lapatinib can harm an unborn baby or cause birth defects if the mother or father is using this medicine. Keep using birth control for at least 1 week after your last dose.

Tell your doctor right away if a pregnancy occurs while either the mother or the father is using lapatinib.

Do not breast-feed while using this medicine, and for at least 1 week after your last dose.

How to use Lapatinib

Usual Adult Dose for Breast Cancer:

HER2-Positive Metastatic Breast Cancer (in combination with capecitabine): 1250 mg orally once a day on Days 1 to 21 continuously in repeating 21-day cycles in combination with capecitabine 2000 mg/m2/day (administered orally in 2 doses approximately 12 hours apart) on Days 1 to 14 in a repeating 21-day cycleHormone Receptor-Positive, HER2-Positive Metastatic Breast Cancer (in combination with letrozole): 1500 mg orally once a day continuously in combination with letrozole 2.5 mg orally once a dayComments:-The dose of this drug should be once daily (5 tablets administered all at once); do not divide the daily dose. is not recommended [see Clinical Pharmacology (12.3)]. Capecitabine should be taken with food or within 30 minutes after food. If a day's dose is missed, the patient should not double the dose the next day. Treatment should be continued until disease progression or unacceptable toxicity occurs.-HER2-positive metastatic breast cancer patients should have disease progression on trastuzumab prior to initiation of therapy with this drug in combination with capecitabine.Uses: -In combination with capecitabine for treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2 and who have received prior therapy including an anthracycline, a taxane, and trastuzumab.-In combination with letrozole for treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer that overexpresses the HER2 receptor for whom hormonal therapy is indicated.

Warnings

Do not use lapatinib if you are pregnant. It could harm the unborn baby.

Lapatinib can cause severe or fatal liver problems. Call your doctor at once if you have: upper stomach pain, itching, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

What other drugs will affect Lapatinib

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect lapatinib. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Disclaimer

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