Selpercatinib

Selpercatinib comes as capsules, so you can take them at home. During treatment you usually see a cancer doctor, a cancer nurse or specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

During treatment you will have regular blood samples taken. This is to check things such as:

• the level of your blood cells
• how well your liver and kidneys are working.

Your doctor, nurse or pharmacist will discuss your treatment plan with you. They will explain how to take selpercatinib. You may be given other medicines to take home. Take all your medicines exactly as your doctor or pharmacist tell you.

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

You take selpercatinib capsules twice a day. Capsules should be taken at the same time every day in the morning and evening. Swallow the capsule whole with a glass of water. They should not be chewed, opened or crushed.

You can usually take selpercatinib with or without food. But selpercatinib must be taken with a meal if you are taking medicines to reduce stomach acid. Your doctor, nurse or pharmacist can talk to you more about this.

It is important to tell your doctor, nurse or pharmacist if you are taking any other medicines before starting selpercatinib. This is because other medicines may affect how selpercatinib works. Always take selpercatinib as explained.

If you are sick just after, or miss a dose, take the next dose of selpercatinib at the scheduled time. Do not take a double dose.

Other things to remember about your capsules: 

• 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 your treatment is stopped return any unused capsules/ tablets to the pharmacist.

Some people have an allergic reaction while having this treatment. Signs of a reaction can include: 

• feeling hot or flushed 
• muscle and joint pain
• a skin rash
• itching
• shivering
• feeling dizzy
• a headache
• feeling breathless.

If you feel unwell or have any of these signs, tell a doctor or nurse straight away. Do not take any more of this treatment until you have spoken to them.

After checking your symptoms, your doctor may prescribe [steroids] until your symptoms are better. It is important that you take these exactly as you have been told by your doctor, nurse or pharmacist.

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

• nosebleeds
• bleeding gums
• heavy periods
• blood in your urine (pee) or stools (poo)
• vomit that looks like ‘coffee grounds’
• tiny red or purple spots on your skin that may look like a rash.

Tell your doctor if you have any unexplained bruising or bleeding. You may need a drip to give you extra platelets. This is called a platelet transfusion.

Sometimes selpercatinib may cause more serious bleeding. Contact your doctor immediately if you have any signs of bleeding.

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.

Selpercatinib can cause a dry mouth. Sipping water regularly helps reduce the dry feeling, so carry a bottle of water with you. Eating soft, moist foods with gravy and sauces is easier than dry or chewy foods.

Tell your doctor if you have a dry mouth. They may be able to prescribe things to help.

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 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.

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 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.

Selpercatinib can increase your blood pressure. A nurse will check your blood pressure before starting selpercatinib and regularly throughout your treatment. If you have headaches, nose bleeds or feel dizzy, let your doctor know. Your doctor can usually prescribe tablets to control high blood pressure.

If you are already on treatment for blood pressure, you will have regular blood pressure checks to make sure it stays under control. Talk to your doctor if you have any concerns.

This treatment may cause headaches or dizziness. If this happens, let your doctor or nurse know. They can do tests to check for the cause. If a headache or dizziness is severe, contact the hospital for advice straight away.

Do not drive or operate machinery if you have dizziness.

This treatment may affect how your liver and kidneys works. This is usually mild. You will have regular blood tests to check how well your liver and kidneys are working. At the start of treatment, you will have a blood test to check your liver:

• every 2 weeks during the first 3 months of treatment
• once a month for the next 3 months of treatment
• regularly thereafter.

This treatment can affect how the heart works. You will have tests to see how well your heart is working. These will be done before starting selpercatinib, after 1 week and at least every month for the first 6 months of treatment.

Contact your doctor straight away on the 24-hour number the hospital has given you if you have any of these symptoms during or after treatment:

• pain or tightness in your chest
• breathlessness
• dizziness
• changes to your heartbeat.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

If the treatment is causing heart problems, your doctor may need to reduce your dose of selpercatinib or ask you to stop taking it.

Feeling tired is a common side effect of this treatment. It is often worse towards the end of treatment and for some weeks after it ends. 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. 

If you feel sleepy, do not drive or use machinery.

This treatment can reduce the number of white cells in your blood. These cells fight infection. If you have any signs of an infection, tell your doctor, nurse or pharmacist. These signs include:

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

Contact the hospital straight away on the 24-hour number if you have any of these symptoms:

• a temperature above 37.5°C 
• a temperature below 36°C
• you feel unwell, even with a normal temperature.

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

• use plain English
• explain medical words
• use short sentences
• use illustrations to explain text
• structure the information clearly
• make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

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