Prescription Required 
Formulation : 
Description
Indications
Lapatinib, when combined with capecitabine, is prescribed for the treatment of a specific form of advanced breast cancer in individuals who have undergone prior chemotherapy. Lapatinib is also employed in conjunction with letrozole to address a particular type of breast cancer in postmenopausal women, where the cancer has metastasized to other body parts.
Classified as a kinase inhibitor, lapatinib operates by inhibiting the abnormal protein responsible for signaling cancer cells to proliferate. This mechanism aids in halting or decelerating the spread of cancer cells.
Uses and Dosage
Lapatinib is administered in tablet form and should be taken orally. Typically, it is taken once a day, at least 1 hour before or 1 hour after a meal. For the treatment of advanced or metastatic breast cancer, it is usually prescribed once daily on days 1 to 21, in conjunction with capecitabine on days 1 to 14, within a 21-day cycle. The cycle may be repeated as advised by your doctor. In the case of treating breast cancer in postmenopausal women, lapatinib is generally taken once daily alongside letrozole.
Take all lapatinib tablets for your daily dose at the same time each day; do not split them for separate doses.
Consistency in the timing is crucial. Adhere to the prescribed dosage and do not exceed or reduce it, or take it more frequently than directed.
Swallow the tablets whole; do not split, chew, or crush them.
Your doctor may adjust your lapatinib dosage gradually based on its efficacy and any side effects you may encounter during treatment. Even if you start feeling well, continue taking lapatinib as directed. Do not discontinue the medication without consulting your doctor.
Due to the potential skin and respiratory absorption of this drug, pregnant women or those planning to conceive should avoid handling the medication or inhaling dust from the tablets.
Adhere to your doctor’s guidelines on the proper administration of capecitabine or letrozole in conjunction with lapatinib.
Side Effects
Some side effects may occur that usually do not need medical attention:
- nausea
- vomiting
- heartburn
- sores on the lips, mouth, or throat
- loss of appetite
- red, painful, numb, or tingling hands and feet
- dry skin
- pain in the arms, legs, or back
- difficulty falling asleep or staying asleep
Inform your healthcare provider immediately if you experience any serious side effects:
- shortness of breath
- dry cough
- coughing up pink or bloody mucus
- fast, irregular, or pounding heartbeat
- weakness
- swelling of the hands, feet, ankles, or lower legs
- rash
- fever
- blistering or peeling skin
Caution
- Before taking lapatinib, inform your doctor or pharmacist about any allergies you may have, as this product may contain inactive ingredients that can trigger allergic reactions or other complications.
- Prior to using this medication, disclose your medical history to your doctor or pharmacist, especially if you have conditions such as heart disease (including irregular heartbeat) or liver disease.
- Lapatinib has the potential to cause QT prolongation, a condition affecting heart rhythm. QT prolongation may rarely lead to serious (and rarely fatal) fast/irregular heartbeat, along with symptoms like severe dizziness and fainting, requiring immediate medical attention. The risk of QT prolongation may be elevated if you have certain medical conditions or are taking drugs that can cause QT prolongation. Inform your doctor or pharmacist about all medications you are taking and if you have a history of certain heart problems or a family history of specific heart issues.
- Low levels of potassium or magnesium in the blood may also increase the risk of QT prolongation. This risk may rise with the use of certain drugs (such as diuretics/”water pills”) or conditions like severe sweating, diarrhea, or vomiting.
- Older adults may be more sensitive to the side effects of lapatinib, particularly QT prolongation.
- If you are pregnant or planning to become pregnant, inform your doctor, as lapatinib should not be used during pregnancy due to potential harm to the unborn baby. Both men and women using this medication should inquire about reliable forms of birth control during treatment and for 1 week after the last dose. If pregnancy occurs, consult your doctor promptly about the risks and benefits of continuing the medication.
- The passage of lapatinib into breast milk is unknown. Breastfeeding is not recommended while using this medication and for 1 week after the last dose due to potential risks to the infant. Consult your doctor before breastfeeding.
Form and Strength
Tykerb is available in the following forms and strengths:
- Tykerb tablet:
- 250 mg
FAQ
Can Tykerb treat any type of breast cancer?
No. Although there are many different types of breast cancer, Tykerb is used to treat certain HER2-positive metastatic breast cancers. Your provider will perform a biopsy or surgery to help figure out the receptor type of your cancer.
Is Tykerb a kind of chemotherapy?
Tykerb is not a chemotherapy medication. Chemotherapy is a class of medication that kills cancer cells in your body. Tykerb doesn’t kill cancer cells but instead slows or stops cancer cell growth.
