Dabrafenib and trametinib

Dabrafenib (Tafinlar®) and trametinib (Mekinst®) are targeted therapy drugs. They can be given together to treat melanoma that has spread or cannot be removed with surgery.

Dabrafenib is given as a capsule, and trametinib is given as a tablet. You usually have them as an outpatient. Your cancer doctor or nurse will tell you how often you will have them.

Like all targeted therapy drugs, dabrafenib and trametinib can cause side effects. Some of them can be serious, so it is important that you read the detailed information below. The effects of targeted therapy vary from person to person. It is important to read about the side effects so that you know what to expect. Your healthcare team can talk to you more about this, and give you advice on how to manage any side effects.

Tell your doctor or nurse straight away if you have a temperature, feel unwell or have severe side effects, including any we don’t mention here.

If you need medical attention for any reason other than cancer, always tell the healthcare staff that you are having this treatment.

What are dabrafenib and trametinib?

Dabrafenib (Tafinlar®) and trametinib (Mekinst®) are types of targeted therapy drugs called kinase inhibitors or cancer growth blockers. They can only be used to treat cancers that have a change in a gene called BRAF. Your doctors will test samples of your tissue that have been taken during a previous surgery to find out if the cancer cells have this change.


How dabrafenib and trametinib work

Kinases are proteins that tell cells when to grow. Cancers with a change in the BRAF gene make abnormal proteins that tell cancer cells to grow and divide. Two of these proteins are called BRAF and MEK. Dabrafenib and trametinib work by blocking these abnormal proteins, and together they can stop the cancer cells growing.

How targeted therapies work

This animation shows how targeted therapies work and what effect they have on the body.

About our cancer information videos

How targeted therapies work

This animation shows how targeted therapies work and what effect they have on the body.

About our cancer information videos


When dabrafenib and trametinib are given

Dabrafenib and trametinib are given to treat melanoma that has spread to other parts of the body or cannot be removed with surgery.

Dabrafenib and trametinib may also be given as part of a clinical trial to treat other types of cancer with a BRAF gene change.


Taking your dabrafenib and trametinib

You usually take dabrafenib twice a day, with about 12 hours between each dose. If you forget to take dabrafenib, and there are more than six hours until the next dose, take it as soon as you remember. If there are fewer than six hours until the next dose, do not take it. Just take the next dose at the usual time.

You usually take trametinib once a day. It should be taken at the same time as either the morning or the evening dose of dabrafenib. If you forget to take the trametinib, and there are more than 12 hours until the next dose, take it as soon as you remember. If there are fewer than 12 hours until the next dose, do not take it. Just take the next dose at the usual time.

Never take a double dose of either drug. If you are sick after taking either drug, do not take another dose, just take the next dose at the usual time.

Take the drugs on an empty stomach with a full glass of water. Do not eat for two hours before you take them, or for one hour after taking them. Try to take them at the same time each day.

Always take your drugs exactly as your nurse or pharmacist explained. This is important to make sure they work as well as possible for you. Your doctor will talk to you about how long to take dabrafenib and trametinib for.

There are some other important things to remember when taking your drugs:

  • Swallow them whole. Don’t chew or crush them.
  • Don’t drink grapefruit juice or eat grapefruit while you are having treatment with dabrafenib.
  • Keep dabrafenib in the original package, and store it at room temperature.
  • Keep trametinib in the original package, and store it in a refrigerator until you open it. Once opened, you can keep trametinib for up to 30 days at room temperature, as long as this is not higher than 30°C.
  • Keep all the drugs safe and out of the reach of children.
  • Return any remaining drugs to the pharmacist if your treatment is stopped.


About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. 

If you are also having treatment with other cancer drugs, you may have some side effects that we haven’t listed here. 

Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. 

It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. 

Your nurse will give you advice about managing your side effects. 

After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. 

Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.


Possible side effects of dabrafenib and trametinib

High temperatures or infection

Dabrafenib and trametinib can cause high temperatures. This usually starts in the first month of treatment. It is important to let your doctor or nurse know if this happens. Some people become seriously unwell because of a high temperature. Check your temperature if you feel hot or cold and shivery, achy or dizzy.

Sometimes dabrafenib and trametinib can also reduce the number of white blood cells in your blood. White blood cells help to fight infection. If the number of your white blood cells is low, you are more likely to get an infection which may also cause a high temperature.

Contact your doctor or the hospital straight away if:

  • your temperature is high, depending on the advice given by your hospital team
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection – this can include feeling shaky, a sore throat, a cough, diarrhoea or needing to pass urine a lot.

Your doctor or nurse may ask you to come to the hospital for a check-up. You may need to stop taking the drugs for a while, or have a lower dose.

Tiredness

Feeling very tired is a common side effect. Try to pace yourself and get as much rest as you need. It helps to balance this with taking some gentle exercise, such as short walks. If you feel sleepy, don’t drive or operate machinery.

Feeling sick

Feeling sick is a common side effect but it’s usually mild and easy to control. If needed, your doctor will prescribe anti-sickness (anti-emetic) drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist explained.

Skin changes

Some mild skin changes are common. They include a rash, redness, itching, dry, rough or scaly skin, or small wart-like growths. Tell your nurse or doctor if you have any of these changes. They can give you advice, and may prescribe creams or medicines to help. Sunlight may make skin symptoms worse. During treatment, wear a suncream with a high sun protection factor (SPF), and cover up with clothing and a hat.

Sore and red hands and feet

Having sore and red palms of hands and soles of feet is called palmar-plantar or hand-foot syndrome. It gets better when treatment ends. Your doctor or nurse can give you advice and prescribe creams to improve the symptoms. It can help to keep your hands and feet cool and to avoid tight-fitting socks, shoes and gloves.

Diarrhoea

If you have diarrhoea, your doctor can prescribe drugs to control it. Take them exactly as your nurse or pharmacist explained. Make sure you drink at least two litres (three and a half pints) of fluids every day if you have diarrhoea.

Rarely, diarrhoea can be more severe. It’s important to contact the hospital if this happens. If you have more than three episodes of diarrhoea a day, contact the hospital on the telephone numbers you have been given and speak to a doctor or nurse.

Constipation

You may be constipated and have tummy pain. Drinking at least 2 litres of fluids (3½ pints) every day will help. Try to eat more foods that contain fibre (such as fruit, vegetables and wholemeal bread) and take some regular gentle exercise.

Dry or sore mouth

Your mouth may become dry or sore. Tell your nurse or doctor if you have any problems with your mouth. They can prescribe medicines to prevent or treat mouth infections and reduce any soreness. It’s important to follow any advice you are given and to drink plenty of fluids.

Headaches

This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.

Muscle and joint pain

You may get pain in your joints or muscles during treatment. Sometimes the pain can be severe. If this happens, tell your doctor so they can give you painkillers. Let them know if the pain does not get better. They can usually increase or change your painkillers to help.

Breathlessness and a cough

You may feel more out of breath than normal or develop a cough. Let your doctor know if you notice this.

Hair loss

Your hair may thin but you are unlikely to lose all the hair from your head. It is almost always temporary, and your hair will grow back after treatment ends. Your nurse can give you advice about coping with hair loss.

High blood pressure

Dabrafenib and trametinib can increase your blood pressure. If you have headaches or nosebleeds or feel dizzy, let your doctor know. Your doctor can usually prescribe tablets to control high blood pressure.

Bruising and bleeding

Dabrafenib and trametinib can reduce the number of platelets in your blood. Platelets are cells which help the blood to clot. Tell your doctor if you have any bruising or bleeding you can’t explain. This includes nose bleeds, bleeding gums, blood spots or rashes on the skin. If your platelet count is very low, you may need a drip to give you extra platelets (platelet transfusion).

Anaemia (low number of red blood cells)

Dabrafenib and trametinib can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells (blood transfusion).

Loss of appetite

You may lose your appetite during treatment and may lose weight. Try to eat small meals regularly. If your appetite doesn’t improve after a few days, let your doctor or nurse know. They can arrange for you to see a dietician who can give you advice. You may be given food supplements or meal replacement drinks to try. Your doctor can prescribe some of these and you can buy them from chemists.

Eye problems

Dabrafenib and trametinib may cause blurry vision. Always tell your doctor or nurse if you notice any change in your vision.

Changes in the kidneys and liver

Dabrafenib and trametinib may cause changes in the way that your kidneys and liver work. Your doctor will take regular blood samples to check your kidneys and liver are working properly.


Less common side effects of dabrafenib and trametinib

Second cancer

Sometimes, dabrafenib and trametinib may increase the risk of developing other types of skin cancer, such as squamous cell or basal cell skin cancer. Usually, these are easily removed with surgery. Your nurse or doctor will tell you what to look for and will check your skin regularly. If you notice anything unusual between appointments, let your nurse or doctor know.

Rarely, a new melanoma or non-skin cancer can develop. But the benefits of treatment usually far outweigh this risk. Your doctor can talk to you about this.

Changes in the way the heart works

Dabrafenib can affect the way the heart works. This is usually temporary. You may have tests to see how well your heart is working before, during and after treatment.

Tell a doctor straight away if you have pain or tightness in your chest, feel breathless or notice changes to your heartbeat at any time during or after treatment. These symptoms can be caused by other conditions, but it is important to get them checked by a doctor.

Raised blood sugar levels

Dabrafenib and trametinib may raise your blood sugar levels. Symptoms of raised blood sugar include feeling thirsty, needing to pass urine more often and feeling tired. Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this.

Side effects can usually be controlled or improved. Always let your doctor or nurse know about any side effects you have so they can help you feel better.


Other information about dabrafenib and trametinib

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain. 

If you have any of these symptoms, contact a doctor straight away. 

A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect cancer treatments or be harmful when you are having them. This includes medicines you can buy in a shop or chemist. Tell your cancer doctor about any medicines you are taking, including vitamins, herbal drugs and complementary therapies.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment. The drugs may harm the developing baby. It is important to use effective contraception during your treatment.

Breastfeeding

Women are advised not to breastfeed while having this treatment and for some time afterwards. This is because the drugs could be passed to the baby through breast milk.

Fertility

Some cancer drugs can affect whether you can get pregnant or father a child.

If you are worried about fertility, it is important to talk with your doctor before you start this treatment. There may be ways to preserve fertility for men and women.

Sex

If you have sex during this treatment, you need to use a condom. This is to protect your partner in case there is any trace of the drug in semen or vaginal fluids.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having this treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.