What is Tykerb® ? (lapatinib)

Tykerb is a targeted therapy used to treat advanced or metastatic breast cancer that is positive for human epidermal growth factor receptor 2 (HER2+) receptor in certain patients who have previously received treatment that included an anthracycline, a taxane, and trastuzumab. Lapatinib is also used to treat metastatic breast cancer that is hormone receptor positive and HER2 receptor positive in postmenopausal women where hormone therapy is appropriate. Lapatinib is manufactured by Novartis Pharmaceuticals.1

What is the ingredient in Tykerb?

The active ingredient in Tykerb is lapatinib, a kinase inhibitor which blocks the HER2 receptor.1

How does lapatinib work?

In breast cancers that are HER2+, the surface of the cancer cells has an excess of HER2 receptors. Having an excess of HER2+ receptors can cause the breast cancers to grow and spread quickly.2

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Lapatinib helps block HER2 receptors from inside the cell. Lapatinib is a small molecule that can pass through the cell wall and connect to the HER2 receptor to disrupt its activity. When used in combination with a medication called Xeloda® (capecitabine), lapatinib may slow the progression of metastatic breast cancer. In postmenopausal women with metastatic breast cancer that is HER2+ and hormone receptor-positive (HR+), lapatinib may also potentially be given in combination with a medication called Femara® (letrozole).1,2

What are some of the possible side effects of lapatinib?

Lapatinib may cause serious side effects including liver damage, which can lead to death. Signs of liver damage include yellowing of the skin or eyes (jaundice), itching, dark-colored urine, or pain or discomfort in the right upper stomach area. Any of these symptoms should be reported to a doctor right away.1,2

The most common side effects experienced by patients taking lapatinib include1,2:

  • Diarrhea
  • Hand-foot syndrome (palmar-plantar erythrodysesthesia), which causes a rash, swelling, redness, and/or pain typically on the palms of the hands and soles of the feet
  • Nausea
  • Rash
  • Vomiting
  • Fatigue

Some people may develop heart problems while taking lapatinib. Symptoms of heart problems, such as a pounding or racing heartbeat, dizziness, light-headedness, tiredness, or shortness of breath, should be reported to a doctor right away.1,2

Diarrhea is a common side effect with lapatinib and may become serious and lead to dehydration or death. Patients who experience severe diarrhea should talk to their doctor for treatment.1,2

Lapatinib may cause lung problems. Patients who experience shortness of breath or persistent coughing should report these symptoms to their doctor.1,2

Lapatinib may cause severe skin reactions, including a rash or red skin, peeling skin, fever, or blistering of the lips, mouth, or eyes. Severe skin reactions can be life-threatening, and any signs of skin reactions should be reported to a doctor.1,2

Things to know about lapatinib

Before taking lapatinib, patients should talk to their doctor about all their health conditions, especially if they have heart problems, liver problems, or are pregnant or planning to become pregnant. Lapatinib should not be used during pregnancy.
Women who can become pregnant, and men with female partners who can become pregnant, should use effective birth control while taking lapatinib and for one week following the final dose of lapatinib (patients should discuss appropriate birth control methods with their doctor).1,2

Before starting treatment with lapatinib and throughout treatment, patients will be tested for their liver and heart function.1

Before starting treatment with lapatinib, patients should talk to their doctor about all their medications (prescription and over-the-counter), herbal supplements, and vitamins they are taking. Some medications or supplements may interfere with each other and may cause side effects.2

While taking lapatinib, patients should avoid eating or drinking grapefruit products, as grapefruit products may increase the levels of lapatinib in the body, which can increase the potential for side effects.2

Lapatinib should not be used by people with an allergy to the medication.2

These are not all the possible side effects of lapatinib. Patients should talk to their doctor about what to expect with treatment with lapatinib.

Dosing information

Lapatinib is a tablet that should be taken orally.1

Your doctor will determine the appropriate lapatinib dosing regimen and administration schedule for you. It is important to follow this schedule exactly as instructed, and not to stop taking lapatinib or any accompanying medications on your own unless you are instructed to do so by your doctor.

For more information, read the full prescribing information of lapatinib.

Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their lapatinib regimen.

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Written by: Editorial Team | Last reviewed: October 2020.