Lapatinib may cause liver damage which can be severe or life-threatening. Liver damage can occur as soon as several days or as late as several months after the start of treatment with lapatinib. Tell your doctor if you have or have ever had liver disease. If you experience any of the following symptoms, call your doctor immediately: itching, yellowing of the skin or eyes, dark urine, pain in the upper right part of the stomach, unusual bleeding or bruising, or pale or dark stools.
Keep all appointments with your doctor and the laboratory. Your doctor will order certain laboratory tests before and during your treatment to see whether your liver is likely to be damaged or has been damaged by lapatinib.
Talk to your doctor about the risks of taking lapatinib.
Lapatinib is used with capecitabine (Xeloda) to treat a certain type of advanced breast cancer in people who have already been treated with other chemotherapy medications. Lapatinib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop or slow the spread of cancer cells.
Lapatinib comes as a tablet to take by mouth. It is usually taken once a day, at least 1 hour before or 1 hour after a meal. Take all of the tablets for your daily dose at one time each day; do not divide the tablets to take as separate doses. Take lapatinib at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take lapatinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Capecitabine is taken in combination with lapatinib, but on a different schedule. Be sure that you understand how and when to take capecitabine. Talk to your doctor and pharmacist if you have any questions about taking capecitabine.
Swallow the tablets whole; do not split, chew, or crush them.
Your doctor may gradually increase or decrease your dose of lapatinib during your treatment. This depends on how well the medication works for you and any side effects you may experience. Continue to take lapatinib even if you feel well. Do not stop taking lapatinib without talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
Do not eat grapefruit or drink grapefruit juice while taking this medication.
Take the missed dose as soon as you remember it that day. However, if you do not remember until the next day, if you cannot remember whether you took the medication, or if you vomit your medication, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
nausea
vomiting
heartburn
sores on the lips, mouth, or throat
loss of appetite
red, painful, numb, or tingling hands and feet
dry skin
pain in the arms, legs, or back
difficulty falling asleep or staying asleep
shortness of breath
dry cough
coughing up pink or bloody mucus
fast, irregular, or pounding heartbeat
weakness
swelling of the hands, feet, ankles, or lower legs
rash
Lapatinib may change the way your heart beats and pumps blood through your body. Your doctor will monitor you carefully to see whether lapatinib has affected your heart. Talk to your doctor about the risks of taking lapatinib.
Lapatinib may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
diarrhea
vomiting
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Last Reviewed - 09/01/2010
AHFS® Consumer Medication Information. © Copyright, 2012. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.