Lapatinib - Benefits, dosage and side effects

Lapatinib is a drug to treat breast cancer, especially those that have spread or metastasized. Generally, this drug will be combined with other anticancer drugs, such as capecitabine

Lapatinib works by inhibiting the work of protein kinase enzymes that play a role in the process of growth, division, and even cell mutation. This way of working will help inhibit and stop the growth and development of cancer cells.

Lapatinib trademark: Tykerb

What is Lapatinib

Class	Prescription drugs
Categories	Anticancer drug class protein kinase inhibitor
Benefits	Treating breast cancer
Used by	Adults and seniors
Lapatinib for pregnant and lactating women	Category D: There is positive evidence of risks to the human fetus, but the benefits may outweigh the risks, for example in dealing with life-threatening situations. It is not yet known whether lapatinib can be absorbed into breast milk or not. If you are breastfeeding, do not use this medicine without consulting your doctor first.
Medicine form	Tablets

Warning Before Taking Lapatinib

Lapatinib should only be consumed according to a doctor's prescription. Before taking lapatinib, you need to pay attention to the following things:

• Tell your doctor about any allergies you have. Lapatinib should not be taken by someone who is allergic to this drug.
• Tell your doctor if you have or have had liver failure, heart disease, kidney disease, electrolyte imbalance, or heart rhythm disturbances, especially QT prolongation syndrome.
• Tell your doctor if you are pregnant, breastfeeding or planning a pregnancy. Use contraception to prevent pregnancy during treatment with lapatinib.
• Avoid consuming grapefruit or grapefruit juice if you are taking lapanitab, as this may cause side effects.
• Tell your doctor if you are taking certain medications, supplements or herbal products.
• Use sunscreen and limit activities that expose you to direct sunlight while taking lapatinib, as this medicine can make your skin more sensitive to sunlight.
• See your doctor immediately if you experience an overdose, allergic reaction to the drug, or more serious side effects after taking lapatinib.

Dosage and Rules for Use of Lapatinib

The doctor will determine the dose and duration of treatment with lapatinib based on the patient's age, condition, and body response to the drug. The following is the dosage of lapatinib based on the condition you want to treat:

• Condition: Breast cancer that has metastasizedDose of 1,250 mg, once a day, for 21 days. This drug can be combined with capecitabine 2,000 mg/m2, 2 times daily on days 1–14 of a 21-day cycle.

• Condition: Breast cancer in postmenopausal womenDose 1,500 mg, once a day in combination with letrozole 2.5 mg, once a day.

How to Take Lapanitib Correctly

Follow the doctor's advice and make sure to read the instructions for use listed on the medicine package. Do not increase or decrease the dose without consulting your doctor first.

Take lapanitib regularly at the same time every day. Lapanitib should be taken 1 hour before meals or after meals. Lapatinib is given with capecitabine or letrozole. Swallow the medicine with the help of a glass of water, do not chew or crush it.

If you forget to take lapatinib, take it immediately if the break with the next consumption schedule is not too close. If it's close, ignore it and don't double the dose.

Do regular check-ups according to the doctor's advice while undergoing treatment with lapatinib. Do not stop taking lapatinib without consulting your doctor first.

During treatment with lapatinib, you may be asked to have complete blood tests, liver function tests, and heart function tests using an EKG, on a regular basis.

Store lapatinib in a dry, closed place, and avoid exposure to direct sunlight. Keep this medicine out of reach of children.

Interaction of Lapatinib with Other Drugs

There are several drug interaction effects that can occur when lapatinib is used with other drugs, namely:

• Increased efficacy of lapaniib when used with ketoconazole, clarithromycin, atazanavir, or ritonavir
• Reduced efficacy of lapaniib when used with carbamazepine, rifampicin, rifabutin, or phenytoin
• Increased risk of QT prolongation syndrome when used with dofetilide, pimozide, procainamide, amiodarone, quinidine, sotalol, or erythromycin
• Increased levels of digoxin

Side Effects and Dangers of Lapatinib

Some of the side effects that can occur after taking lapatinib are:

• Nausea or vomiting
• Headache
• stomach ache
• Thrush
• Dry skin
• Difficulty sleeping
• Rash, swelling, redness, or blisters on the feet or hands

Check with your doctor if the side effects above don't go away or get worse. Immediately see a doctor if an allergic reaction occurs to the drug which can be characterized by symptoms such as an itchy rash on the skin, swelling of the eyelids or lips, or difficulty breathing.

In addition, you should also go to the doctor immediately if you experience more serious side effects, such as:

• Wheezing, severe coughing, shortness of breath
• Chest pain, irregular or very fast heart rate
• Dizzy so heavy that you faint
• Unusual tired
• Swelling in the feet or hands