Tucatinib

Tucatinib comes as tablets you can take at home. You take tucatinib twice a day, with or without food. You should wait 12 hours between each dose. Try to take your tablets at the same times each day.

If you are taking capecitabine tablets, you can take your tucatinib at the same time.

Always take your tucatinib tablets exactly as explained. This is important to make sure they work as well as possible for you. Make sure you:

• swallow the tablets whole with a glass of water
• do not chew, open or crush the tablets.

If you forget to take the tablets, you should take your next dose at your regular time. If a full day has passed, let your doctor or nurse know. Do not take a double dose.

Other things to remember about your tablets:

• Keep them in the original package and at room temperature, away from heat and direct sunlight.
• Keep them safe and out of sight and reach of children.
• If you are sick just after taking the tucatinib tablets, do not take another dose. Contact your healthcare team for advice.
• If your treatment is stopped, return any unused tablets to the pharmacist.

Your nurse or pharmacist may also give you other medicines to take home. Take all your medicines exactly as they have been explained to you. Do not stop taking any of your medicines unless your doctor tells you to.

How long you have trastuzumab depends on your situation. Your doctor, nurse or pharmacist will talk to you about your treatment plan.

If the cancer is advanced, trastuzumab might be given for as long as it is controlling the cancer.

This treatment may cause severe diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. If you have a stoma, it will be more active than usual. 

Your doctor, nurse or pharmacist may give you anti-diarrhoea drugs to take at home. 

If you have diarrhoea or a mild increase in stoma activity, follow their advice about: 

• taking anti-diarrhoea drugs 
• how much and what type of fluids to drink 
• any changes to your diet that might help. 

Contact the hospital straight away on the 24-hour number if:

• you have diarrhoea at night 
• you have uncomfortable stomach cramps
• you have diarrhoea 4 or more times in a day 
• you have a moderate increase in stoma activity 
• the anti-diarrhoea drugs do not work within 24 hours.

You may need to give a stool sample, or go to hospital to have fluids through a drip or antibiotics.

This treatment may affect how your liver works. You will have blood tests before your treatment and every 3 weeks during treatment to check how well your liver is working.

Sometimes liver changes can be serious. Contact the hospital straight away if you have any of these symptoms during treatment or after it finishes:

• yellow skin or eyes
• feeling very sleepy
• dark urine (pee)
• unexplained bleeding or bruising
• itching
• pain in the upper right side of your tummy
• loss of appetite or feeling sick.

Your doctor, nurse or pharmacist will prescribe anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as they tell you to, even if you do not feel sick. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluid often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or if you are sick (vomit) 1 to 2 times in 24 hours, contact the hospital on the 24-hour number as soon as possible. They will give you advice. They may change your anti-sickness treatment. Let them know if you still feel sick.

This treatment can affect your skin. It may cause a rash, which may be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using soap-free cleansers and unperfumed moisturising cream every day. 

Always tell your doctor or nurse about any skin changes. They can give you advice and may prescribe creams or medicines to help. Changes to your skin usually improve when treatment ends.

This treatment can affect the palms of your hands and the soles of your feet. This is called palmar-plantar or hand-foot syndrome. 

If you have white skin these areas may become red. If you have black or brown skin, these areas might get darker. 

The skin on the palms of your hands and the soles of your feet may:

• be sore
• be painful, tingle, or swell
• peel, crack or blister. 

If you have any of these symptoms, contact the hospital straight away on the 24-hour number. They can give you advice. This is especially important if you have any broken skin or if walking is difficult. They can prescribe creams and painkillers to help.

You can care for your hands and feet by: 

• keeping your hands and feet cool by washing in cool water
• gently moisturising your hands and feet regularly
• wearing gloves to protect your hands and nails when working in the house or garden
• wearing loose cotton socks and avoiding tight-fitting shoes and gloves.

This treatment may cause a sore mouth and throat. You may also get mouth ulcers. This can make you more likely to get a mouth or throat infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

Contact the hospital straight away on the 24-hour number, if:

• your mouth or throat is sore, or affecting how much fluid you can drink or food you can eat 
• your mouth, tongue, throat or lips have any blisters, ulcers or white patches. 

They can give you advice, and mouthwash or medicines to help with the pain or to treat any infection. Follow their advice and make sure you:

• drink plenty of fluids
• avoid alcohol and tobacco
• avoid food or drinks that irritate your mouth and throat.

You may get pain in your muscles or joints. If this happens, tell your doctor or nurse. They can give you advice and painkillers or other drugs to help. Being physically active and keeping to a healthy weight may help with the pain. It can keep your joints flexible and reduce stress on them. If the pain does not get better, tell your doctor or nurse. They may talk to you about changing to a different hormonal drug.

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

• throbbing pain or swelling in a leg or arm
• reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
• suddenly feeling breathless or coughing.

Always call 999 if you have:

• chest pain
• difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Some medicines can affect how this treatment works or be harmful when you are having it.

Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

• medicines you have been prescribed
• medicines you buy in a shop or chemist
• vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

St. John’s wort

You should not take any herbal drugs containing St. John’s wort while having tucatinib. It can make the treatment work less well.

Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

If your immune system is weak, you should not have live vaccinations. Live vaccines can make you unwell because they contain a very weak version of the illness they will protect you against. Live vaccines include Zostavax^®, which is a shingles vaccine, and the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

You are advised not to breastfeed while having this treatment, or for at least a week after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.