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.

<p></p> <p></p> <p></p> <p>Lapatinib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

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nausea</li>
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vomiting</li>
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heartburn</li>
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sores on the lips, mouth, or throat</li>
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loss of appetite</li>
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red, painful, numb, or tingling hands and feet</li>
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dry skin</li>
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pain in the arms, legs, or back</li>
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difficulty falling asleep or staying asleep</li></ul></p> <p></p> <p>Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section or the SPECIAL PRECAUTIONS section, call your doctor immediately:

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shortness of breath</li>
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dry cough</li>
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coughing up pink or bloody mucus</li>
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fast, irregular, or pounding heartbeat</li>
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weakness</li>
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swelling of the hands, feet, ankles, or lower legs</li>
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rash</li></ul>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 <a href='http://www.fda.gov/Safety/MedWatch'>http://www.fda.gov/Safety/MedWatch</a>] or by phone [1-800-332-1088].</p>

Before taking lapatinib, tell your doctor and pharmacist if you are allergic to lapatinib, any other medications, or any of the ingredients in lapatinib tablets. Ask your pharmacist for a list of the ingredients. tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: certain antibiotics such as clarithromycin (Biaxin, in Prevpac), erythromycin (E.E.S., E-Mycin, Erythrocin), moxifloxacin (Avelox), rifabutin (Mycobutin), rifampin (Rifadin, in Rifamate, in Rifater, Rimactane), rifapentine (Priftin), sparfloxacin (Zagam) (not available in the U.S.), and telithromycin (Ketek); antifungals such as itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend); calcium channel blockers such as amlodipine (Norvasc, in Caduet and Lotrel), diltiazem (Cardizem, Dilacor, Tiazac, others), felodipine (Plendil, in Lexxel), nifedipine (Adalat, Nifedical XL, Procardia, others), nisoldipine (Sular), and verapamil (Calan, Isoptin, Verelan, others); cisapride (Propulsid) (not available in the U.S.); dexamethasone (Decadron, Dexpak); certain medications for depression such as nefazodone; certain chemotherapy medications including daunorubicin (Cerubidine, DaunoXome), doxorubicin (Adriamycin, Doxil, Rubex), epirubicin (Ellence), idarubicin (Idamycin), tamoxifen (Nolvadex), valrubicin (Valstar), vinblastine, and vincristine; certain medications for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) including atazanavir (Reyataz), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), and saquinavir (Invirase); medications for irregular heartbeat including amiodarone (Cordarone), disopyramide (Norpace), dofetilide (Tikosyn), procainamide (Procanbid), quinidine, and sotalol (Betapace, Betapace AF, Sorine); certain medications for seizures such as carbamazepine (Carbatrol, Epitol, Tegretol), phenobarbital (Luminal), and phenytoin (Dilantin, Phenytek); pimozide (Orap); and thioridazine. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with lapatinib, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. tell your doctor and pharmacist what herbal products you are taking, especially St. John's wort. tell your doctor if you have or have ever had a slow, fast, or irregular heartbeat; a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death); a low level of magnesium or potassium in your blood;or heart or lung disease. you should know that lapatinib often causes diarrhea, which can be severe. Call your doctor if you have diarrhea while taking lapatinib. Your doctor may tell you to drink plenty of liquids, make changes in your diet, and take medication to control the diarrhea and prevent dehydration (loss of too much water from your body). Call your doctor immediately if you experience any of the following symptoms of dehydration: extreme thirst, dry mouth and/or skin, decreased urination, sunken eyes, or fast heartbeat.

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. Symptoms of overdose may include:

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diarrhea</li>
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vomiting</li></ul>