Proper Use

Drug information provided by: Micromedex

Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine comes with a patient information insert. Read and follow the instructions carefully. Ask your doctor if you have any questions.

This medicine should be taken at least 1 hour before or 1 hour after a meal. All of the tablets are taken together as one dose.

Lapatinib is given together with capecitabine or letrozole. It is important that you take each medicine at the right time. Follow your doctor's instructions on when to take these medicines.

Do not eat grapefruit or drink grapefruit juice while you are using this medicine.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For advanced or metastatic breast cancer with capecitabine:
      • Adults—1250 milligrams (mg) or 5 tablets together as a single dose once a day for 21 days. Your doctor may tell you to repeat the 21-day cycle.
      • Children—Use and dose must be determined by your doctor.
    • For metastatic breast cancer with letrozole:
      • Adults—1500 milligrams (mg) or 6 tablets together as a single dose once a day.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.