Lapatinib oral tablet

What is this medicine?

LAPATINIB (la PA ti nib) is a medicine that targets proteins in cancer cells and stops the cancer cells from growing. It is used to treat some advanced breast cancers. It is often used along with other cancer treatments.

How should I use this medicine?

Take this medicine by mouth with a glass of water. Take this medicine on an empty stomach, at least 1 hour before or after a meal. Do not take with food. Follow the directions on the prescription label. Do not cut, crush, or chew this medicine. Do not take with grapefruit juice. Take your medicine at regular intervals. Do not take it more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed. This medicine is not approved for use in children.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:

• allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue

• breathing problems

• diarrhea

• redness, blistering, peeling or loosening of the skin, including inside the mouth

• signs and symptoms of a dangerous change in heartbeat or heart rhythm like chest pain; dizziness; fast or irregular heartbeat; palpitations; feeling faint or lightheaded, falls

• signs and symptoms of liver injury like dark yellow or brown urine; general ill feeling or flu-like symptoms; light-colored stools; loss of appetite; nausea; right upper belly pain; unusually weak or tired; yellowing of the eyes or skin

• swelling in your legs and feet

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

• cough

• decreased appetite

• mouth sores

• nausea, vomiting

What may interact with this medicine?

Do not take this medicine with any of the following:

• cisapride

• dronedarone

• fluconazole

• pimozide

• posaconazole

• saquinavir

• thioridazine

This medicine may also interact with the following medications:

• antiviral medicines for HIV or AIDS

• certain antibiotics like clarithromycin, erythromycin, and telithromycin

• certain antibiotics like rifabutin, rifampin, and rifapentine

• certain medicines for depression, anxiety, or psychotic disturbances

• certain medicines for fungal infections like itraconazole, ketoconazole, or voriconazole

• certain medicines for seizures like carbamazepine, phenobarbital, phenytoin

• dexamethasone

• digoxin

• nefazodone

• other medicines that prolong the QT interval (cause an abnormal heart rhythm) like dofetilide, ziprasidone

• St. John's Wort

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from moisture. Keep tightly closed. Throw away any unused medicine after the expiration date.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

• heart disease

• heart rhythm problems (irregular heartbeat)

• high blood pressure

• history of low levels of potassium or magnesium

• liver disease

• an unusual reaction to lapatinib, other medicines, foods, dyes, or preservatives

• pregnant or trying to get pregnant

• breast-feeding

What should I watch for while using this medicine?

Visit your doctor for checks on your progress. You will need to have regular blood tests while on this medicine.

Do not become pregnant while taking this medicine or for 1 week after stopping it. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. Men should not father a child while taking this medicine and for 1 week after stopping it. There is a potential for serious side effects to an unborn child. Talk to your health care professional or pharmacist for more information. Do not breast-feed an infant while taking this medicine or for 1 week after stopping it.