Dabrafenib and trametinib

Dabrafenib (Tafinlar®) and trametinib (Mekinst®) are targeted therapy drugs. They are given together to treat melanoma and non-small cell lung cancer.

What are dabrafenib and trametinib?

Dabrafenib (Tafinlar®) and trametinib (Mekinst®) are targeted drugs that can be are used together to treat  melanoma and non-small cell lung cancer. It is best to read this information with either our general information about melanoma or non-small cell lung cancer. 

Both drugs are targeted therapy drugs known as cancer growth inhibitors.

This treatment is only used if the cancer cells have a change (mutation) in a gene called BRAF. The BRAF gene produces a protein that makes the cancer cells grow. Dabrafenib and trametinib block this protein.

Dabrafenib and trametinib may be used to treat melanoma that:   

  • is stage 3 and was completely removed with surgery – you  have the drugs for up to 1 year to try to reduce the risk of the melanoma coming back (called adjuvant treatment)
  • cannot be removed with surgery or melanoma that has spread to other organs of the body.  

It may also be used to treat advanced non-small cell lung cancer (NSCLC).

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

How dabrafenib and trametinib are given

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. 

You will have:

  • dabrafenib as a capsule
  • trametinib as a tablet.

The nurse or pharmacist will give you these to take at home.

While you are having this treatment, your doctor will take regular blood samples to check your kidneys and liver are working properly.

If you are taking dabrafenib and trametinib after surgery to reduce the risk of melanoma coming back you have this treatment for up to 1 year.

If the cancer is advanced you take this treatment for as long as it working for you and the side effects are not causing you problems.

Your doctor, nurse or pharmacist will discuss your treatment plan with you.

Taking your capsule and tablets

The nurse or pharmacist will give you the capsules and tablets to take home. Always take them exactly as explained. This is important to make sure they work as well as possible for you. 

Take the drugs on an empty stomach with a full glass of water. Do not eat for 2 hours before you take them. After taking them do not eat for 1 hour.  

They must be swallowed whole with a glass of water. They should not be chewed or crushed. Take them at the same time every day.    

Do not drink grapefruit juice or eat grapefruit or Sevillle oranges while taking this treatment. 


You usually take dabrafenib twice a day, with about 12 hours between each dose. If you forget to take it and there are more than 6 hours until your next dose, take it as soon as you remember. If there are fewer than 6 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 at the same time as either the morning or the evening dose of dabrafenib. If you forget to take it and there are more than 12 hours until your 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.

Other things to remember about your capsules/tablets:
  • Keep dabrafenib in the original package and at room temperature, away from heat and direct sunlight. 
  • Keep trametinib in the original package and store it in a refrigerator until you open it. Once opened, you can keep it for up to 30 days at room temperature not higher than 30°C. 
  • Keep them safe and out of the sight and reach of children. 
  • If your treatment is stopped, return any unused capsules or tablets to the pharmacist. 

About side effects

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

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Other cancer treatments may cause different side effects. If you are also having other cancer treatment, you may have other side effects.

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

  • drugs to help control some side effects 
  • advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

Serious and life-threatening side effects

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

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Common side effects

High temperatures

This treatment can cause high temperatures. This usually starts in the first month of treatment. A high temperature can cause symptoms such as: 

  • night sweats
  • feeling hot or cold
  • feeling shivery
  • feeling achy

Contact the hospital if you have these symptoms. You will usually be told to check your temperature. A high temperature can also be caused by infection so your doctor or nurse may ask you to come to the hospital for a check-up. 

If the treatment is causing a high temperature, your doctor may tell you to stop taking dabrafenib for a while, or to take a lower dose of it. 

Feeling tired

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.

Feeling sick

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


This treatment can cause bleeding, which may be mild or more serious. 

Contact a doctor immediately if you have any of these symptoms: 

  • severe headaches or dizziness
  • passing blood in your stools (poo) or black ‘tarry’ stools
  • vomit that looks like ‘coffee grounds’
  • sudden tummy pain
  • coughing up blood
  • blood in the urine (pee).

Swelling of nasal passages and back of throat

Your nose may feel stuffy or blocked and you may have sore throat when taking this treatment. 


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. 

Headache and dizziness

You may have headaches or feel dizzy. 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 use machinery if you feel dizzy.

Muscle pain or joint pain

You may have muscle or joint pain or muscle spasms (cramps). The pain is usually mild and can be relieved with painkillers. Ask your doctor for advice. 

Rarely, this treatment can cause a condition where muscle breaks down and affects the kidneys. Always tell your doctor if:

  • muscle pain does not get better
  • muscle pain is causing weakness 
  • your urine (pee) is darker than normal. 

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • a fever (high temperature)
  • breathlessness.

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

Changes in your blood pressure

Dabrafenib and trametinib can affect your blood pressure. It may make cause high or sometimes low blood pressure. Your blood pressure will be checked before and during treatment.  High blood pressure can usually be controlled with tablets. 

Loss of appetite

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.

Skin changes

This treatment often causes mild skin changes. They include:

  • a rash
  • redness
  • itching
  • dry, rough or scaly skin
  • small wart-like growths (called papillomas)
  • infections in the skin or nails.

Tell your nurse or doctor if you have any of these changes. They can give you advice, and can prescribe creams and medicines to help. 

If you are out in the sun, use a sun cream with a high sun protection factor of at least SPF 30 to protect your skin.

Rarely, a much more serious skin condition can develop. You may have a skin rash which then blisters, and your skin can peel. You may also feel unwell with flu-like symptoms such as a high temperature and joint pain. If you have any of these symptoms, contact your doctor or hospital immediately.

New skin cancer

Dabrafenib and trametinib increase the risk of skin cancer. Your doctor will check your skin before and during treatment.

If a skin cancer develops it can usually be 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.

Hand-foot (palmar-plantar) syndrome

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.

Fluid build-up

Some people notice their hands and feet become swollen. This is caused by a build- up of fluid. Less commonly this treatment can cause swelling around the eyes. 

Less common side effects

Hair loss

You might notice that your hair slowly gets thinner. But you are very unlikely to lose all the hair from your head. Your hair can also become more brittle. Your nurse can give you information about coping with hair loss. Your hair will usually go back to normal after treatment ends.

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.

Eye problems

This treatment may affect the eyes. Your eyes will be checked by your doctor while you are taking this treatment. Always tell your doctor or nurse if you notice:

  • any changes in your vision, such as blurring or loss of vision 
  • any eye pain or redness
  • your eyes have become more sensitive to light. 

If your eyes are affected, you may need to have the dose of trametinib reduced.  

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.

Raised blood sugar levels

This treatment may raise your blood sugar levels and increase the risk of diabetes. 

You will have regular blood tests to check this. 

Signs of raised blood sugar include:

  • feeling thirsty
  • needing to pass urine (pee) more often than usual
  • feeling more tired than usual.

Contact the hospital on the 24-hour number if you have these symptoms during treatment or after it ends.

If you already have diabetes, your blood sugar levels may be higher than usual. You may need advice and support from your GP or diabetes team about managing this.

Tummy pain

This may be caused by diarrhoea or constipation. Rarely it can be a sign of a more serious problem linked to the pancreas or to a hole in the bowel lining.  If you develop severe tummy pain contact the hospital for advice straight away.

Effects on the heart

This treatment can affect how the heart works. You may have tests to check how well your heart is working. These may be done before, during and after treatment.

If the treatment is causing heart problems, your doctor may change the type of treatment you are having.

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

  • breathlessness
  • dizziness
  • changes to your heartbeat
  • swollen feet and ankles.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor. 

Always call 999 if you have:

  • chest pain, pressure, heaviness, tightness or squeezing across the chest
  • difficulty breathing.

Other information

Blood clot risk

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.

Other medicines

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: 


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 will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. 

Birth control using hormones (contraceptive pills, injections or patches) may not work as well while you are taking this treatment. It is important to use another effective method of birth control, so you do not become pregnant.

Your doctor, nurse or pharmacist can tell you more about this.


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.


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 have sex during this treatment, your cancer team will usually advise using barrier protection such as condoms.

Medical and dental 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.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

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:

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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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Date reviewed

Reviewed: 01 October 2021
Next review: 01 March 2024

This content is currently being reviewed. New information will be coming soon.

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Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

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