Generic name: tucatinib (too-KA-ti-nib)
Drug class: HER2 inhibitors
Medically reviewed by Drugs.com. Last updated on Sep 25, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antineoplastic Agent
Pharmacologic Class: Tyrosine Kinase Inhibitor
Uses for tucatinib
Tucatinib is used in combination with trastuzumab and capecitabine to treat metastatic HER2-postive breast cancer (cancer that has already spread including the brain) or whose cancer cannot be removed by surgery in patients who have received one or more anti-HER2 breast cancer treatments. It belongs to the group of medicines, called antineoplastics.
Tucatinib interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells may also be affected by the medicine, other unwanted effects will also occur. Some of these may be serious and must be reported to your doctor.
Tucatinib is available only with your doctor's prescription.
Before using tucatinib
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For tucatinib, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to tucatinib or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of tucatinib in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of tucatinib in the elderly. However, elderly patients are more likely to have serious unwanted effects (eg, diarrhea, nausea, and vomiting), which may require caution in patients receiving tucatinib.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking tucatinib, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using tucatinib with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Abiraterone Acetate
- St John's Wort
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of tucatinib. Make sure you tell your doctor if you have any other medical problems, especially:
- Kidney disease, severe (when used together with capecitabine and trastuzumab)—Use is not recommended.
- Liver disease, severe—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper use of tucatinib
Medicines used to treat cancer are very strong and can have many side effects. Before using tucatinib, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
Take tucatinib exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
Tucatinib comes with a patient information insert. Read and follow the instructions carefully. Ask your doctor if you have any questions.
You may take tucatinib with or without food.
Swallow the tablet whole. Do not crush, break, or chew it. Take the medicine about 12 hours apart or at the same time each day.
Tucatinib is given together with trastuzumab and capecitabine. It is important that you take each medicine at the right time. Follow your doctor's instructions on when to take these medicines.
The dose of tucatinib will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of tucatinib. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For treatment of advanced or metastatic breast cancer with trastuzumab and capecitabine:
- Adults—300 milligrams (mg) 2 times a day. Your doctor may adjust your dose as needed and tolerated.
- Children—Use and dose must be determined by your doctor.
- For treatment of advanced or metastatic breast cancer with trastuzumab and capecitabine:
If you miss a dose of tucatinib, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
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. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Tucatinib should be used within 3 months after opening the bottle. Dispose any unused medicine after 3 months.
Precautions while using tucatinib
It is very important that your doctor check your progress at regular visits to make sure tucatinib is working properly. Blood tests may be needed to check for unwanted effects.
Using tucatinib while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment with tucatinib and for at least 1 week after your last dose. Male patients who have female partners should use effective birth control during treatment with tucatinib and for at least 1 week after the last dose. If you think you have become pregnant while using tucatinib, tell your doctor right away.
Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.
Tucatinib may cause severe diarrhea, which may lead to serious complications, including dehydration, low blood pressure (hypotension), or kidney failure. Your doctor will give you medicines to help prevent diarrhea during treatment with tucatinib. If you have any questions about this or if diarrhea continues, or gets worse, check with your doctor.
Talk with your doctor before using tucatinib if you plan to have children. Some men and women using tucatinib have become infertile (unable to have children).
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Tucatinib side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Bloody nose
- burning, numbness, tingling, or painful sensations
- clay colored stools
- dark urine
- decreased or loss of appetite
- mood or mental changes
- nausea and vomiting
- pale skin
- severe diarrhea
- skin rash, itching
- swelling of the feet or lower legs
- stomach pain or tenderness
- troubled breathing with exertion
- unsteadiness or awkwardness
- unusual bleeding or bruising
- unusual tiredness or weakness
- weakness of the arms, hands, legs, or feet
- yellow eyes or skin
- Muscle spasm or jerking of all extremities
- loss of bladder control
- sudden loss of consciousness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Difficulty in moving
- loss of weight
- muscle pain or stiffness
- pain in the joints
- redness, swelling, pain of the skin
- scaling of the skin on the hands and feet
- swelling or inflammation of the mouth
- ulceration of the skin
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
- What’s the difference between tucatinib and neratinib?
- What's the mechanism of action for tucatinib?
More about tucatinib
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- En Español
- Drug class: HER2 inhibitors
- Other brands
Related treatment guides
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