Lapatinib (Tykerb)

Lapatinib may cause liver damage which can be severe or life-threatening. Liver damage can occur as soon as several days or as late as several months after the start of treatment with lapatinib. Tell your doctor if you have or have ever had liver disease. If you experience any of the following symptoms, call your doctor immediately: itching, yellowing of the skin or eyes, dark urine, pain in the upper right part of the stomach, unusual bleeding or bruising, or pale or dark stools.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain laboratory tests before and during your treatment to see whether your liver is likely to be damaged or has been damaged by lapatinib.

Talk to your doctor about the risks of taking lapatinib.

The basics

Lapatinib (brand name – Tykerb) along with capecitabine (Xeloda) is an FDA-approved treatment for breast cancers that have already been treated with other chemotherapy medications.

Along with letrozole (Femara), it treats breast cancers in post-menopausal women (women who have experienced a change of life; end of menstrual periods) that have spread to other body parts.

Lapatinib (Tykerb) is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop or slow the spread of cancer cells.

Let us walk you through the key things you need to know about lapatinib.

How should I take Lapatinib (Tykerb)?

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Lapatinib (Tykerb) comes as a tablet to take orally once a day, at least 1 hour before or 1 hour after a meal. Do not divide the tablets to take as separate doses. Take lapatinib at around the same time every day. Take lapatinib exactly as directed. Do not take more or less of it or more often than your doctor prescribes.

Swallow the tablets whole; do not split, chew, or crush them. Continue to take lapatinib even if you feel well.

Do not stop taking lapatinib without talking to your doctor. You can help them by tracking your side effects in Ankr.

What are the side effects of lapatinib (Tykerb)?

Common side effects

Serious side effects

  • Shortness of breath (Dyspnea)
  • Dry cough
  • Coughing up pink or bloody mucus
  • Fast, irregular, or pounding heartbeat
  • Swelling of the hands, feet, ankles, or lower legs
  • heart problems

Lapatinib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication. If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online or by phone (1-800-332-1088).

Use the free Ankr platform or Ankr app to track your symptoms.

What special precautions should I follow?

Before taking lapatinib (Tykerb)

  • tell your doctor about your allergies.
  • tell your doctor about other intakes.
  • tell your doctor if you have or have ever had any disease, symptoms, or treatment.
  • tell your doctor if you are pregnant or plan to become pregnant. Talk to your doctor about birth control methods you can use during treatment.

While you are on lapatinib (Tykerb)

  • If you become pregnant while taking lapatinib, call your doctor immediately. Lapatinib may harm the fetus.
  • Tell your doctor if you are breastfeeding or plan to breastfeed. You should not breastfeed while taking lapatinib and for one week after your final dose.
  • Call your doctor immediately if you experience any of the symptoms of dehydration and Diarrhea.

How should I safely store and dispose of lapatinib?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

You should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website ( for more information if you do not have access to a take-back program.

I forgot a dose. What should I do?

Take the missed dose as soon as you remember it that day. However, if you do not remember until the next day, if you cannot remember whether you took the medication, or if you vomit your medication, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

In case of an emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Symptoms of overdose may include the following:

What special dietary instructions should I follow?

Do not eat grapefruit or drink grapefruit juice while taking this medication.

Brand names

  • Tykerb®

Last Revised – 06/11/2023, FDA update- 06/15/2019, SG

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DISCLAIMER: No part of this content constitutes medical advice, opinion, or should be used for medical decision making without consultation with a licenced medical practitioner and under a patient-provider relationship. All information on the website is provided without any claims of accuracy. For full terms and conditions, visit this link. Content curated by the Ankr team.

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