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 used to treat melanoma and non-small cell lung cancer.

They may sometimes be used to treat other cancers as part of a clinical trial. It is best to read this information with our general information about the type of cancer you have.

Dabrafenib (Tafinlar®) and trametinib (Mekinst®) belong to a type of targeted therapy drugs known as cancer growth inhibitors. 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 to find out if the cancer cells have this change. These samples will have been taken during a previous surgery.

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

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.

Your course of treatment

Dabrafenib comes as a capsule, and trametinib as a tablet which you take at home. If they are being used to treat a cancer that cannot be removed with surgery, you will usually take them for as long as they are working and not causing unacceptable side-effects.

If you are taking them to reduce the risk of melanoma coming back after surgery you will take them for 12 months.

Taking your capsule and tablets

The nurse or pharmacist will give you the capsules/tablets to take home. They may also give you anti-sickness drugs and other medicines to take home. Take all your drugs exactly as they have been explained to you. This is important to make sure they work as well as possible.

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 6 hours until the 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. 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.

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. Do not chew or crush them.
  • Do not 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 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 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 have not 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

High temperatures

Dabrafenib and trametinib 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

Your doctor or nurse will tell you to check your temperature if you have these symptoms. They will also tell you when to contact the hospital for advice if your temperature is high. 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 very tired or weak 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, do not drive or operate 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 explained.


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

Depending on where the bleeding is, it may cause:

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

Contact a doctor immediately if you have any of these symptoms

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.

Soreness and redness of palms of hands and soles of feet

This is called palmar-plantar or hand-foot syndrome. It gets better when treatment ends. Your doctor or nurse may 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.


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 (3½ pints) of fluids every day if you have diarrhoea.

Rarely, diarrhoea can be more severe. It is 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.


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 for advice. Your doctor can give you drugs called laxatives to help.

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 and do not drive.

Muscle pain or joint pain

You may have muscle or joint pain or muscle spasms (cramps). Pain is usually mild and can be relieved with painkillers ask your doctor for advice. Rarely this treatment can cause muscle to break down. It is important to tell your doctor if muscle pain does not get better, is causing weakness or if your urine is darker than normal. Your doctor may tell you to stop taking the treatment for a time.

Changes in your blood pressure

Dabrafenib and trametinib can affect your blood pressure. It may make cause high or low blood pressure Your blood pressure will be checked before starting treatment.

Headaches, nosebleeds or feeling dizzy can be signs of high blood pressure. Tell your doctor if you have them. High blood pressure can usually be controlled with tablets.

Loss of appetite

This treatment can affect your appetite. If you have a poor appetite, try to eat little amounts as often as possible.

It is important to try to eat well during your treatment. If you are having problems ask your nurse for advice and you can also ask to see a dietitian. You can add extra energy and protein to your diet with everyday foods or by using food supplements.

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.

Sunlight can make skin symptoms worse. During treatment, use a sun cream with a high sun protection factor and UVA protection (at least SPF 30 and UVA 4 or 5 stars). When you are out in the sun cover up with clothing and a hat.

Dabrafenib and trametinib increase the risk of skin cancers. If a skin cancer develops it is usually easy to remove 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 people develop a severe skin reaction when taking dabrafenib and trametinib. The signs of this may include:

  • feeling generally unwell with flu-like symptoms and an itchy rash
  • raised red patches on the skin with circles that look like a target or "bulls-eye"
  • sores in the mouth or on the genitals
  • sore, red eyes
  • sensitivity to light and blurred vision.

It is important to contact a doctor for advice straight away if you develop any of these signs.

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.

Other possible side effects

Hair loss

Your hair may get thinner. But you are unlikely to lose all the hair from your head. Hair loss usually starts after your first or second treatment. It is almost always temporary, and your hair will usually grow back after treatment finishes. Your nurse can talk to you about ways to cope with hair loss.

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

Trametinib 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:

  • a change in your 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 can raise your blood sugar levels. If you have a raised blood sugar level, you may:

  • feel thirsty
  • need to pass urine (pee) more often
  • feel 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. You may need to change your insulin or tablet dose.

Tummy pain

This may be caused by diarrhoea or constipation but rarely it can be a sign of something more serious. If you develop severe tummy pain or any tummy pain that doesn’t get better after a couple of days contact the hospital for advice.

Second cancer

There is an increased risk of developing skin cancers and a slightly increased risk of developing other (non-skin related) cancers when taking this treatment. Your doctor may arrange for you to have tests for other cancers while you are taking it. If you have concerns about your risk talk to your doctor.

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.

Contact a doctor straight away if you:

  • have pain or tightness in your chest
  • feel breathless or dizzy
  • feel your heart is beating too fast or too slowly.

These symptoms can be caused by other conditions, but it is important to get them checked by a doctor.

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

Blood clot risk

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

  • throbbing pain, redness or swelling in a leg or arm
  • suddenly feeling breathless or coughing
  • sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

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

You can help reduce the risk of developing a blood clot by:
  • staying active during treatment
  • drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.

Other medicines

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


Your doctor will advise you not to get pregnant or father a child while having this treatment and for some time afterwards. The drugs may harm the developing baby. It is important to use effective contraception. If you use hormonal contraception (such as taking contraceptive pills, or using injections or patches) they 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. Ask your doctor, nurse or pharmacist for advice.


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


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 course of 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 you are having cancer 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.