Generic Name: lapatinib (la-PA-ti-nib)
Brand Name: Tykerb
Severe and sometimes fatal liver problems may occur with the use of lapatinib. These problems may develop within days or several months after you start using it. Tell your doctor if you have a history of liver problems. Your doctor may need to check your liver function before you start lapatinib and while you are taking it. Be sure to keep all doctor and lab appointments. Contact your doctor right away if you develop dark urine, pale stools, severe stomach pain, severe tiredness or weakness, unusual itching, or yellowing of the eyes or skin.
Lapatinib is used for:
Treating certain types of advanced or metastatic breast cancer. It is used in combination with another medicine (capecitabine or letrozole). It may also be used for other conditions as determined by your doctor.
Lapatinib is a protein-tyrosine kinase inhibitor. It works by preventing the growth of cancer cells.
Do NOT use lapatinib if:
- you are allergic to any ingredient in lapatinib
- you have developed liver problems from taking lapatinib in the past
- you have uncorrected low blood potassium or magnesium levels
Contact your doctor or health care provider right away if any of these apply to you.
Before using lapatinib:
Some medical conditions may interact with lapatinib. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are able to become pregnant
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have bone marrow problems, low white blood cell counts, or low blood platelets
- if you have a history of liver problems, lung problems, heart problems (eg, heart failure), or an irregular heartbeat (eg, QT prolongation)
- if you have low blood potassium or magnesium levels
- if you are taking a calcium channel blocker (eg, diltiazem, verapamil, nifedipine) or you take medicine for depression or stomach problems (eg, ulcers, heartburn, reflux)
- if you take any medicine that may increase the risk of a certain type of irregular heartbeat (prolonged QT interval). Check with your doctor or pharmacist if you are unsure if any of your medicines may increase the risk of this type of irregular heartbeat
- if you have received an anthracycline (eg, doxorubicin) in the past
Some MEDICINES MAY INTERACT with lapatinib. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Antiarrhythmics (eg, amiodarone, quinidine), arsenic, astemizole, bepridil, chloroquine, cisapride, dofetilide, dolasetron, domperidone, droperidol, halofantrine, haloperidol, iloperidone, ketolides (eg, telithromycin), macrolide antibiotics (eg, erythromycin), maprotiline, methadone, paliperidone, pentamidine, phenothiazines (eg, thioridazine), pimozide, quinolone antibiotics (eg, ciprofloxacin), romidepsin, tacrolimus, terfenadine, toremifene, certain tricyclic antidepressants (eg, doxepin, nortriptyline), vandetanib, or ziprasidone because the risk of a certain type of irregular heartbeat (QT prolongation) may be increased
- Atazanavir, azole antifungals (eg, itraconazole, ketoconazole, posaconazole), nefazodone, protease inhibitors (eg, boceprevir, indinavir, ritonavir), or voriconazole because they may increase the risk of lapatinib's side effects
- Carbamazepine, dexamethasone, hydantoins (eg, phenytoin), nevirapine, phenobarbital, primidone, rifamycins (eg, rifampin) or St. John's wort because they may decrease lapatinib's effectiveness
- Digoxin, midazolam, or paclitaxel because the risk of their side effects may be increased by lapatinib
This may not be a complete list of all interactions that may occur. Ask your health care provider if lapatinib may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use lapatinib:
Use lapatinib as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- An extra patient leaflet is available with lapatinib. Talk to your pharmacist if you have questions about this information.
- Take lapatinib by mouth at least 1 hour before or 1 hour after eating.
- Do not eat grapefruit or drink grapefruit juice while you use lapatinib.
- If you miss a dose of lapatinib, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use lapatinib.
Important safety information:
- Tell your doctor or dentist that you take lapatinib before you receive any medical or dental care, emergency care, or surgery.
- Diarrhea is a common side effect of lapatinib. If diarrhea occurs, you will need to take care not to become dehydrated. Contact your doctor for instructions.
- If you may become pregnant, you must use an effective form of birth control while you take lapatinib. If you have questions about effective birth control, talk with your doctor.
- Lab tests, including liver function, heart function, and complete blood cell counts, may be performed while you use lapatinib. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
- Lapatinib should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: Lapatinib may cause harm to the fetus. Do not become pregnant while you are using it. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using lapatinib while you are pregnant. It is not known if lapatinib is found in breast milk. Do not breast-feed while taking lapatinib.
Possible side effects of lapatinib:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Back pain; diarrhea; dry skin; fingernail or toenail changes; headache; indigestion; loss of appetite; mild hair loss or thinning; mouth sores; nausea; nosebleed; redness and tingling of the hands and feet; tiredness; trouble sleeping; vomiting.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; dark urine; dizziness or light-headedness; fast or irregular heartbeat; pale stools; persistent loss of appetite; severe or persistent cough; severe pain, redness, or swelling of the hands or feet; severe stomach pain or diarrhea; severe tiredness or weakness; shortness of breath; unusual bruising or bleeding; unusual itching; yellowing of the eyes or skin.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include fast heartbeat; sore scalp; swelling or soreness of the mouth.Proper storage of lapatinib:
Store lapatinib between 59 and 86 degrees F (15 and 30 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep lapatinib out of the reach of children and away from pets.
- If you have any questions about lapatinib, please talk with your doctor, pharmacist, or other health care provider.
- Lapatinib is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information should not be used to decide whether or not to take lapatinib or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about lapatinib. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to lapatinib. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using lapatinib.
Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.