Tucatinib (too-KA-ti-nib)

Treats cancer, including breast and colorectal cancer.

Brand Name(s):

Tukysa

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet

• Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
• Swallow the tablet whole. Do not crush, break, or chew it. Take it about 12 hours apart or at the same time each day.
• This medicine is given together with trastuzumab and capecitabine. Follow your doctor's instructions on when to take these medicines.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose: If you miss a dose of this medicine, skip the missed dose and take your next dose at your usual time. If you vomit after taking your medicine, do not take an extra dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. This medicine should be used within 3 months after opening the bottle. Dispose any unused medicine after 3 months.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how tucatinib works. Tell your doctor if you are using digoxin, gemfibrozil, itraconazole, metformin, midazolam, repaglinide, or rifampin.

Warnings While Using This Medicine:

• This medicine may cause birth defects if either partner is using it during conception or pregnancy. Tell your doctor right away if you or your partner becomes pregnant. Use an effective form of birth control during treatment with this medicine and for at least 1 week after the last dose. Male patients with female partners should use an effective form of birth control during treatment and for at least 1 week after the last dose.
• Do not breastfeed while you are using this medicine and for at least 1 week after your last dose.
• Tell your doctor if you have kidney disease, or liver disease.
• This medicine may cause the following problems:
  • Severe diarrhea, which may lead to serious problems (including dehydration, low blood pressure, kidney problems)
  • Liver problems
• Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
• This medicine could cause infertility. Talk with your doctor before using this medicine if you plan to have children.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes
• Severe diarrhea
• Unusual bleeding, bruising, or weakness

If you notice these less serious side effects, talk with your doctor:

• Blistering, pain, rash, redness, or swelling of the skin on your hands and feet
• Headache, fever
• Loss of appetite
• Sores or white patches on your lips, mouth, or throat
• Tiredness

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088