If you have breast cancer, your doctor might suggest Tukysa (pronunciation too-KYE-sah) as a treatment option for you.

Tukysa is a prescription medication that’s used to treat certain kinds of HER2-positive breast cancer. For this purpose, it’s usually taken together with two other cancer drugs, Herceptin (trastuzumab) and Xeloda (capecitabine).

The active ingredient in Tukysa is tucatinib. An active ingredient is what makes a drug work.

Tukysa comes as a tablet that you swallow. It belongs to a group of drugs called kinase inhibitors.

This article describes the dosages of Tukysa, as well as its strengths and how to take the drug. To learn more about Tukysa, including details about its uses, see this in-depth article.

Note: This chart highlights the basics of Tukysa’s dosage. Be sure to read on for more details. And please keep in mind that this article covers Tukysa’s standard dosage schedule, which is provided by the drug’s manufacturer. But always follow the dosing instructions your doctor or healthcare professional (HCP) prescribes.

Tukysa formTukysa strengthUsual dosage
oral tablet50 milligrams (mg) or 150 mg300 mg twice daily

This section covers standard dosage information for Tukysa. But the dosage your doctor prescribes may depend on certain factors, such as other conditions that you have. Your doctor will discuss with you the best dosage of Tukysa for treating your cancer.

What is Tukysa’s form?

Tukysa comes as a tablet that you swallow.

What strengths does Tukysa come in?

Tukysa comes in the following strengths:

  • 50 milligrams (mg)
  • 150 mg

What are the usual dosages of Tukysa?

Usually, your doctor will start you on the dosage of Tukysa recommended by the manufacturer. In some cases, your doctor may adjust your dosage over time based on your response to therapy. They’ll ultimately prescribe a dosage that minimizes side effects while producing the desired response.

The information below describes dosages that are commonly used or recommended. But be sure to take the dosage your doctor prescribes for you. They’ll determine the best dosage to fit your needs.

The usual dosage of Tukysa for certain kinds of HER2-positive breast cancer is 300 mg taken by mouth twice daily.

You’ll take Tukysa together with Herceptin (trastuzumab) and Xeloda (capecitabine) to treat your breast cancer. Follow the dosage instructions your doctor gives you for these medications.

If you have additional questions about Tukysa dosing, ask your doctor.

Is Tukysa used long term?

Yes, Tukysa is typically used as a long-term treatment. If you and your doctor determine that Tukysa is safe and effective for you, it’s likely that you’ll use it long term.

Your doctor will probably recommend that you continue taking Tukysa unless you have severe side effects or your cancer gets worse. Talk with your doctor about the best treatment plan for you.

Dosage adjustments

In some cases, your doctor may recommend a dose reduction of Tukysa. These situations include the following:

Tukysa is a tablet that you swallow twice daily with or without a meal. You should try to take your doses of the drug 12 hours apart at about the same time each day. This helps keep a steady level of the medication in your body throughout the day so the drug may work effectively.

Be sure to swallow your Tukysa tablets whole. Do not break, crush, or chew the tablets, and do not take any tablets that are broken.

If you vomit after taking a dose of Tukysa, do not take another dose. Instead, take your next dose at its regularly scheduled time.

If you have trouble swallowing tablets, see this article for tips on how to take this form of medication.

For information on Tukysa expiration, storage, and disposal, see this article. You can also find this information on the drug’s package insert.

Accessible drug containers and labels

If you find it hard to read the prescription label on your medication, tell your doctor or pharmacist. Some pharmacies may provide medication labels that:

  • have large print or use braille
  • feature a code that you can scan with a smartphone to change the text to audio

Your doctor or pharmacist may be able to recommend pharmacies that offer these accessibility features if your current pharmacy doesn’t.

The dosage of Tukysa you’re prescribed may depend on several factors. These include:

  • side effects you may have from Tukysa
  • other medications you take that may interact with Tukysa
  • other conditions you may have (see “Dosage adjustments” under “What is Tukysa’s dosage?”)

If you miss a dose of Tukysa, skip the missed dose and take your next dose at its usual time.

If you need help remembering to take your dose of Tukysa on time, try using a medication reminder. This can include setting an alarm or downloading a reminder app on your phone.

Don’t take more Tukysa than your doctor prescribes. Taking more than this can lead to serious side effects.

What to do in case you take too much Tukysa

Call your doctor right away if you think you’ve taken too much Tukysa. You can also call 800-222-1222 to reach the American Association of Poison Control Centers, or use its online resource. But if you have severe symptoms, call 911 (or your local emergency number) immediately or go to the nearest emergency room.

The sections above describe the usual dosages provided by the drug’s manufacturer. If your doctor recommends Tukysa for you, they’ll prescribe the dosage that’s right for you.

Remember, you should not change your dosage of Tukysa without your doctor’s recommendation. Only take Tukysa exactly as prescribed. Talk with your doctor if you have questions or concerns about your current dosage.

Here are some examples of questions you may want to ask your doctor:

  • Will you increase my dosage of Tukysa if it’s not working for me?
  • Do my other medications affect my dosage of Tukysa?
  • Can my dosage be decreased if I’m having side effects from Tukysa?

To share advice and learn how others with breast cancer are managing their condition, join the Bezzy BC online breast cancer community. And to get news about treatments for your condition and more, sign up for Healthline’s breast cancer newsletter.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.