Entrectinib (Rozlytrek®)

Entrectinib comes in capsules. This means you can take it at home. 

During a course of treatment, you will meet someone from your cancer team, such as a:

• cancer doctor
• specialist nurse
• specialist pharmacist. 

This is who we mean when we mention doctor, nurse or pharmacist in this information.

During your course of treatment, you will have regular blood tests. This is to check that it is safe for you to have treatment.

If there are any changes in your test results, your doctor may temporarily delay your treatment or reduce the dose. 

Your cancer team will discuss your treatment plan with you.

They will give you the capsules to take home. They may give you capsules of different strengths. Always take them exactly as they tell you to. This is important to make sure they work as well as possible for you.

Your cancer team may also give you anti-sickness drugs and other medicines to take home. Take all your capsules or tablets exactly as they tell you.

You usually take entrectinib for as long as it is working for you and side effects can be managed. Do not stop taking entrectinib without talking to your doctor first.

Entrectinib is taken once a day. Try to take the capsules at the same time each day. You can take them with or without food. Swallow the capsules whole with water. Do not chew, open, or dissolve them. 

If you are sick (vomit) immediately after taking the capsules take another dose. But, if you are sick a while after taking the capsules, do not take another dose. Take your next dose at the usual time.  

If you forget to take your capsules and there is more than 12 hours until your next dose, take your capsules as soon as you remember. 

If there is less than 12 hours until your next dose, do not take the missed dose. Take your next dose at the usual time and let your doctor or nurse know. Do not take a double dose.

Other things to remember about your capsules:

• Wash your hands after taking your capsules.
• Other people should avoid direct contact with this drug.
• Keep them in the original package with any bottles tightly closed. Keep at room temperature, away from moisture, heat and direct sunlight.
• Keep them safe, somewhere children cannot see or reach them.
• Do not throw away unused capsules or tablets. Return them to your cancer team at the hospital.

Grapefruit and oranges: Do not eat grapefruit or Seville oranges, or drink grapefruit or Seville orange juice while taking this medicine. This is because it may increase the risk of side effects.

Lactose: Entrectinib capsules contain lactose. Lactose is a type of sugar found in milk and dairy products. If you have a lactose intolerance, talk to your doctor. 

Food Colouring: Entrectinib contains sunset yellow FCF (E110) in the 200mg hard capsules. This is a food colouring that may cause an allergic reaction.

Entrectinib may affect your ability to drive or use machines. It may cause you to: 

• have blurred vision
• feel dizzy or faint
• feel tired
• feel confused or see things that are not there (hallucinations). 

If this happens, you should not drive, use a bicycle, or operate machinery. Talk to your doctor, nurse or pharmacist about whether it is okay for you to drive or use machines.

Feeling tired is a common side effect of this treatment. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired. 

Entrectinib can affect your sleep. If you are tired, do not drive, ride a bike or use machinery.

Entrectinib can affect the nervous system. You may have:

• problems with balance and coordination
• tingling, numbness or a burning feeling in your hands and feet
• blurred vision
• problems with swallowing.

Tell your doctor if you notice any of these side effects.

This treatment may also cause:

• changes in your mood
• confusion
• memory problems
• seeing things that are not there (hallucinations).

Contact the hospital straight away on the number you have been given if you have any of these side effects.

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If your white blood cell count is low, you may be more likely to get an infection. A low white blood cell count is called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. If you have any of the following symptoms, contact the hospital straight away on the 24-hour number:

• a temperature above 37.5°C 
• a temperature below 36°C
• you feel unwell, even with a normal temperature
• you have symptoms of an infection.

Symptoms of an infection include:

• feeling shivery and shaking
• a sore throat
• a cough
• breathlessness
• diarrhoea
• needing to pass urine (pee) often, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

You will have regular blood tests during treatment. If your white blood cell count is low, your doctor may stop your treatment for a short time, until your cell count increases. Sometimes they will reduce the dose of your treatment.

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

• very low in energy
• breathless 
• dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

• Drink at least 2 litres (3½ pints) of fluids each day.
• Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
• Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital on the 24-hour number for advice. They can give you drugs called laxatives to help. 

If you have not been able to pass stools for over 2 days and are being sick, contact the 24-hour number straight away. 

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

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

• taking anti-diarrhoea medicines 
• drinking enough fluids to keep you hydrated and to replace lost salts and minerals
• any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

You may get pain in your tummy (abdomen), or have indigestion. Your doctor, nurse or pharmacist can give you advice or treatment to help. Contact the hospital straight away on the 24-hour number if your symptoms do not go away, or get worse.

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 appetite. Don’t worry if you do not eat much for 1 or 2 days. But if your appetite does not come back after a few days, or if you are losing weight, tell your doctor, nurse or pharmacist. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

This treatment may make you feel dry (dehydrated). Tell your doctor or nurse if you have signs of dehydration such as:

• feeling thirsty
• feeling dizzy or tired
• passing small amounts of urine
• dry mouth and eyes.

It is important to drink 2 litres (3½ pints) a day.

Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. You may also get a bitter or metallic taste in your mouth. Your doctor, nurse or pharmacist can give you advice. It might help to try:

• sucking sugar-free sour or boiled sweets
• eating cold foods
• eating sharp-tasting fresh fruit.

Taste changes usually get better after treatment ends. We have more information about coping with changes to taste.

This treatment can cause a build-up of fluid in the body. This will slowly get better after treatment ends. Contact the hospital on the 24-hour number if you:

• are gaining weight 
• have swelling in your face, legs or ankles.

They can give you advice and treatment to help.

This treatment can cause changes to the lungs. It can cause a build-up of fluid around the lungs (pleural effusion).

Contact the hospital straight away on the number you have been given if you develop:

• a cough
• wheezing
• breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

You may gain weight when you are having this treatment. Eating healthily and being active can help you keep to a healthy weight. Your doctor, nurse or dietitian can give you more advice.

You may get pain in your muscles, bones or joints with this treatment. It may cause bones to break more easily than usual. Contact the hospital straight away on the 24-hour number if: 

• you have pain 
• you cannot walk or move properly 
• a bone is out of place.  

Let your doctor know if you have a condition that might increase your risk of broken bones such as osteoporosis or osteopenia.

This treatment may cause headaches. If you have headaches, tell your doctor, nurse or pharmacist. They can give you advice about painkillers that may help. Tell them if the headache does not get better, or gets worse.

This treatment can affect how the kidneys work. This is usually mild and goes back to normal after treatment ends. You will have blood tests to check how well your kidneys are working. Tell your doctor or nurse if you: 

• have blood in your urine (pee)  
• have difficulties passing urine 
• are passing less urine than usual.

Drinking fluids helps protect your kidneys. The advice is usually to try to drink at least 2 litres (3½ pints) of fluid each day. But follow any advice from your doctor, nurse or pharmacist about how much is right for you.

This treatment may affect how your liver works. This is usually mild. You will have blood tests to check how well your liver is working.

This treatment may affect your skin. It may cause a rash, which might be itchy. Your doctor or nurse can tell you what to expect. 

If you are out in the sun, use a sun cream of at least SPF 30. SPF stands for sun protection factor. Cover up with clothing and a hat. Always tell your doctor or nurse about any changes to your skin. They can give you advice and may prescribe creams or medicines to help. Skin changes usually improve when treatment ends.

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 while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

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.

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. You may need a pregnancy test before starting treatment. It is important to use contraception to prevent pregnancy. Follow their advice about:

• what types of contraception to use 
• how long after treatment you should continue to use contraception. 

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

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.