Lapatinib, Oral la-PA-ti-nib

What are other names for this medicine?

Type of medicine: antineoplastic (anticancer); chemotherapy

Generic and brand names: lapatinib, oral; Tykerb

What is this medicine used for?

This medicine is taken by mouth to treat breast cancer. It is used when other cancer medicines have not worked. It is used along with a medicine called capecitabine (Xeloda).

It may be used to treat other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• chemotherapy or radiation therapy
• heart failure, long QT syndrome (problems with electrical activity in the heart muscle), or any other heart disease
• liver or kidney disease

Females of childbearing age: This medicine is not usually given to pregnant women because it can harm the baby. If you are pregnant, tell your healthcare provider. Do not become pregnant during treatment with this medicine. If you become pregnant, contact your healthcare provider right away. Do not breast-feed while you are taking this medicine.

How do I use it?

Check the label on the medicine for directions about your specific dose. Take this medicine exactly as your healthcare provider prescribes. Do not take more of it or for longer than prescribed. Taking too much increases the risk of serious side effects.

Take this medicine on an empty stomach, at least 1 hour before or 1 hour after food.

What if I miss a dose?

If you miss a daily dose and do not remember until the next day, skip that dose and take the regular daily dose. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: severe diarrhea, vomiting.

What should I watch out for?

Contact your healthcare provider right away if you develop unusual tiredness or weakness; severe nausea or vomiting; dark urine; light colored bowel movements; or yellowing of your eyes or skin. Rarely, this medicine can cause liver problems. You need to have liver function tests regularly.

You need to have blood tests regularly to see how this medicine affects you. Keep all appointments for tests.

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Shortness of breath; abnormal heartbeat; unusual tiredness or weakness; severe diarrhea, nausea, or vomiting.

Other: Rash, dry skin, diarrhea, tiredness, trouble sleeping, nausea, vomiting, loss of appetite, mouth sores, red or painful hands or feet.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• antiarrhythmics (medicines to treat irregular heartbeat) such as amiodarone (Cordarone, Pacerone), digoxin (Lanoxin, Lanoxicaps), and quinidine
• antibiotics such as ciprofloxacin (Cipro), clarithromycin (Biaxin), erythromycin (Erythrocin, E.E.S., EryPed, E-Mycin), isoniazid, norfloxacin (Noroxin), rifampin (Rifadin, Rimactane), rifabutin (Mycobutin), and telithromycin (Ketek)
• antidepressants such as fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), nefazodone (Serzone), paroxetine (Paxil), and sertraline (Zoloft),
• antifungals such as itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend)
• antiseizure medicines such as carbamazepine (Tegretol), phenobarbital, phenytoin (Dilantin), and primidone (Mysoline)
• anti-HIV medicines such as delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), nevirapine (Viramune), ritonavir (Norvir), saquinavir (Invirase), and stavudine (Zerit)
• benzodiazepines such as midazolam (Versed) and triazolam (Halcion)
• calcium channel blockers such as diltiazem (Cardizem, felodipine, isradipine (DynaCirc CR), nicardipine (Cardene), nifedipine (Adalat CC, Procardia), and verapamil (Calan, Covera-HS, Isoptin SR, Verelan, Tiazac)
• cholesterol-lowering medicines (statins) such as atorvastatin (Lipitor), lovastatin (Mevacor), rosuvastatin (Crestor), and simvastatin (Zocor)
• cyclosporine (Gengraf, Neoral, Sandimmune)
• diabetes medicines such as pioglitazone (Actos), repaglinide (Prandin), and rosiglitazone (Avandia)
• digoxin (Lanoxin)
• medicines to treat erectile dysfunction such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra)
• medicines to treat stomach acid such as cimetidine (Tagamet), esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix), and ranitidine (Zantac)
• modafinil (Provigil)
• other cancer medicines
• St. John's wort
• warfarin (Coumadin)

Do not eat grapefruit or drink grapefruit juice while taking this medicine. Grapefruit affects the way this medicine works and may increase the risk of side effects.

If you are not sure if your medicines might interact, ask your pharmacist or healthcare provider. Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.