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, for example capecitabine.

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

Trademark of lapatinib: Tykerb

What is Lapatinib 

class Prescription drug
Category Anticancer drug class of protein kinase inhibitors
Benefit Treating breast cancer
Used by Adults and seniors
Lapatinib for pregnant and lactating women Category D: There is positive evidence of risk to the human fetus, but the benefits may outweigh the risks, for example in dealing with a life-threatening situation.

It is not known whether lapatinib is absorbed into breast milk or not. If you are breastfeeding, do not use this medicine without consulting your doctor first.

Drug form Tablet

Precautions 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 history of allergies you have. Lapatinib should not be taken by someone who is allergic to this drug.
  • Tell your doctor if you have had or currently have 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 while on treatment with lapatinib.
  • Avoid consuming grapefruit or grapefruit juice if you are currently taking lapanitib, because it can 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 on treatment with lapatinib, because this drug can make your skin more sensitive to sunlight.
  • Immediately consult a doctor if you experience an overdose, drug allergic reaction , or more serious side effects after taking lapatinib.

Dosage and Rules for Use Lapatinib

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

  • Conditions: Breast cancer that has metastasized
    . Dosage 1,250 mg once a day for 21 days. This medication may be combined with capecitabine 2,000 mg/m2, twice daily on days 1–14 of a 21-day cycle.
  • Conditions: Breast cancer in menopausal women
    . Dose of 1,500 mg once a day in combination with letrozole 2.5 mg once a day.

How to Consume Lapantib Properly

Follow the doctor 's recommendations and be sure to read the instructions for use listed on the drug packaging. Do not increase or decrease your dose without consulting your doctor first.

Take lapanitib regularly at the same time every day. Lapantib should be consumed 1 hour before eating or after eating. Lapatinib is given together 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, consume it immediately if the gap with the next consumption schedule is not too close. If it's close, ignore it and don't double the dose.

Carry out routine controls according to the doctor's recommendations while undergoing treatment with lapatinib. Do not stop taking lapatinib without consulting your doctor first.

While undergoing treatment with lapatinib, you may be asked to routinely undergo complete blood tests, liver function tests, and heart function tests using an EKG, regularly.

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

Lapatinib Interactions with Other Drugs

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

  • Increased effectiveness of lapanitib when used with ketoconazole , clarithromycin, atazanavir, or ritonavir
  • Decreased effectiveness of lapanitib 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
  • Elevated digoxin levels

Side Effects and Dangers of Lapatinib

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

  • Nausea or  vomiting
  • Headache
  • Stomach ache
  • Sprue
  • Dry skin
  • Hard to sleep
  • 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 go to the doctor if a drug allergic reaction appears which can be characterized by symptoms in the form of an itchy rash on the skin, swelling of the eyelids or lips, or difficulty breathing.

In addition, you should also see a doctor immediately if you experience more serious side effects, such as:

  • Wheezing, severe coughing, shortness of breath
  • Chest pain , irregular or very fast heartbeat
  • Dizziness is so severe that you faint
  • Unusual fatigue
  • Swelling in the feet or hands
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