Tykerb (Lapatinib)

Indications

Tykerb (generically known as lapatinib) is a prescription medication used to treat certain types of HER2-positive breast cancer in adults. It is a HER2 inhibitor targeted therapy, which works by blocking certain proteins that promote cancer cell growth.

Lapatinib works as a dual tyrosine kinase inhibitor, which blocks the action of two enzymes called Epidermal Growth Factor Receptor (EGFR) and Human Epidermal Growth Factor Receptor 2 (HER2). EGFR and HER2 are two proteins on the surface of cells that help regulate cell growth and division.

In some cases, mutations in these proteins cause them to be overactive, leading to the unchecked growth and division of cancer cells. Tykerb blocks these proteins, slowing or stopping the growth of cancer cells. It is used to treat advanced or metastatic HER2-positive breast cancer in combination with other medications.

Use and Dosage

Tykerb comes as a tablet to be taken orally one hour before or after a meal, usually once daily or as prescribed by your doctor. Swallow the tablets whole; do not split, chew, or crush them.

The recommended dosage for Tykerb for advanced or metastatic breast cancer is 1,250 mg given orally once daily on Days 1-21 continuously in combination with letrozole, or capecitabine and letrozole. However, the dose may vary depending on your medical condition, response to treatment, and the medications you are taking. Do not take Tykerb more frequently than prescribed or change your dose without consulting with your healthcare provider.

Avoid consuming grapefruit or grapefruit juice while using Tykerb, as it may increase the risk of side effects. If you have any questions about consuming other foods or drinks while taking Tykerb, consult with your doctor or pharmacist. Since Tykerb Tablet can be absorbed through the skin and lungs, pregnant women and those who could become pregnant should not handle the tablets or breathe the dust from them. Follow your doctor's instructions on how to correctly take capecitabine or letrozole with lapatinib.

Remember to always follow your doctor's instructions and ask them any questions if you are unsure about how to take Tykerb properly.

Side Effects

Common Side Effects of Tykerb (Lapatinib):

• Difficulty falling asleep or staying asleep
• Dry skin
• Heartburn
• Loss of appetite
• Nausea
• Pain in the arms, legs, or back
• Red, painful, numb, or tingling hands and feet
• Sores on the lips, mouth, or throat
• Vomiting

Serious Side Effects of Tykerb (Lapatinib):

• Blistering or peeling skin
• Coughing up pink or bloody mucus
• Dry cough
• Fast, irregular, or pounding heartbeat
• Fever
• Rash
• Shortness of breath
• Swelling of the hands, feet, ankles, or lower legs
• Weakness

Forms and Strength

Tykerb (Lapatinib) is available in the following forms and strength:

Tykerb: Tablet

• 250 mg

Cautions

• Tykerb is likely to increase exposure to concomitantly administered drugs, and concentrations of Lapatinib are likely.
• Tykerb can increase the risk of liver function test abnormalities or liver damage. Patients with liver damage or impairment should use Tykerb with caution.
• Tykerb can cause severe diarrhea, which can lead to dehydration. Patients should be monitored for signs of diarrhea and should receive appropriate treatment as needed.
• Tykerb can cause QTc prolongation. This means that the drug can affect the electrical activity of the heart, potentially leading to an irregular heartbeat. Patients with a history of heart disease or arrhythmias should use Tykerb with caution.
• Tykerb can cause interstitial lung disease. Patients should be monitored for signs of cough, fever, or chest discomfort and should contact their healthcare provider immediately if these symptoms occur.
• Tykerb can cause fetal harm if administered during pregnancy. Patients should use effective contraception while taking the drug and for at least one week after their last dose.
• Tykerb can cause skin rash, which may be severe in some cases. Patients should contact their healthcare provider if they have a rash while taking Tykerb.
• Tykerb can cause eye problems, including keratitis, which is inflammation of the cornea. Patients should be monitored for signs of eye problems and should seek medical attention if they experience symptoms such as eye pain or redness.
• Tykerb can interact with other drugs, such as CYP3A4 inhibitors or inducers, and this can affect the concentration of Lapatinib. Patients should inform their healthcare provider of all medications they are taking before starting treatment with Tykerb.
• Tykerb can cause fatigue and dizziness. Patients should avoid activities that require mental alertness, such as driving or operating machinery, until they know how the drug affects them.

Frequently Asked Questions (FAQ)

How long is Tykerb treatment?

The duration of Tykerb treatment can vary depending on the individual patient and their response to the drug. Treatment may continue if the cancer responds to the medication.

Can Tykerb be taken during pregnancy?

No, Tykerb can cause fetal harm if administered during pregnancy. Patients should use effective contraception while taking the drug and for at least one week after their last dose.

What should I do if I miss a dose of Tykerb?

If a dose of Tykerb is missed, it should be taken as soon as possible. If it is almost time for the next scheduled dose, patients should skip the missed dose and continue with their regular dosing schedule.

Can Tykerb be taken with food?

Yes, Tykerb should be taken with food, as this can increase the absorption of the drug.

How often do I need to have liver function tests while taking Tykerb?

Liver function tests should be monitored regularly while taking Tykerb, typically every 4-6 weeks.

Can Tykerb cause hair loss?

Hair loss is not a common side effect of Tykerb.

Resources

• https://medlineplus.gov/druginfo/meds/a607055.html
• https://www.goodrx.com/lapatinib/what-is
• https://www.breastcancer.org/treatment/targeted-therapy/tykerb
• https://www.drugs.com/tykerb.html
• https://www.webmd.com/drugs/2/drug-147813/tykerb-oral/details
• https://www.accessdata.fda.gov/drugsatfda_docs/label/2010/022059s007lbl.pdf