Dabrafenib and trametinib

Dabrafenib and trametinib are types of targeted cancer drugs. Dabrafenib is also known as Tafinlar. Trametinib is also known as Mekinist.

You pronounce dabrafenib as da-bra-fe-nib. And trametinib as tra-met-i-nib.

These drugs are for children, young people and adults in certain situations.

An adult might have it for:

  • melanoma skin cancer
  • non small cell lung cancer (NSCLC)

Some children and young people over 1 years of age may have it for a type of brain tumour called a glioma.

You can only have these drugs if your cancer has a BRAF gene change Open a glossary item (mutation). You have tests on the cancer cells to check for this gene change before you start treatment.

The following information is based on adults having this combination of drugs.

How does dabrafenib and trametinib work?

Dabrafenib and trametinib are types of cancer growth blockers. They work by targeting certain proteins that help cancer cells grow. By blocking these proteins, this combination of drugs stops or slows down the growth of cancer cells.

How do you take dabrafenib and trametinib?

You take trametinib as a tablet and dabrafenib as a capsule.

You swallow them whole with a full glass of water. You take them on an empty stomach. This means you take them at least 1 hour before a meal or 2 hours after a meal.

You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

Whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, not more or less.

Talk to your healthcare team before you stop taking or miss a dose of a cancer drug.

How often do you take dabrafenib and trametinib?

You take dabrafenib twice a day, morning and evening, about 12 hours apart. You take trametinib only once a day.

For advanced melanoma and NSCLC you take dabrafenib and trametinib for as long as they are working or until the side effects get too bad.

If you’re having them after surgery, you take them for up to 12 months.


You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

You usually have regular scans such as a CT scan and other tests during this treatment.

Your doctor or nurse will explain what tests you need and how often.

What are the side effects of dabrafenib and trametinib?

Side effects can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects 

  • your side effects aren’t getting any better

  • your side effects are getting worse

Early treatment can help manage side effects better. 

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

High temperature, cold or flu-like symptoms

Symptoms include a high temperature, sore throat, runny nose, headaches, muscle aches, shivering (chills), sneezing or coughing.

Let your doctor or nurse know if you have any of these symptoms or feel generally unwell.

Loss of appetite

You might have less of an appetite for various reasons when you are having cancer treatment. Sickness, taste changes or tiredness can all put you off food and drinks.


Tell your healthcare team if you are getting headaches. They can give you painkillers.


This drug might make you feel dizzy. Don’t drive or operate machinery if you have this.

High blood pressure (hypertension)

Tell your doctor or nurse if you have headaches, nosebleeds, blurred or double vision or shortness of breath. You have your blood pressure checked regularly.


These drugs can cause bleeding from anywhere in your body. This is usually mild but there is a risk of a serious bleed. Signs of bleeding include blood in your urine or poo (stool), black stool, vomiting or coughing up blood, headaches, dizziness or feeling weak.

Contact your doctor or nurse straight away if you have any signs of bleeding.


Tell your doctor or nurse if you develop a cough. This could be due to an infection.

Diarrhoea or constipation

Tell your healthcare team if you have diarrhoea or constipation. They can give you medicine to help. 

Feeling or being sick

Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

Skin problems

Symptoms of skin problems can include a rash, dry skin, itching and reddening of the skin.

Less commonly these medicines can cause thickening of the outer layer of the skin. It can also make the skin scaly, crusty, cracks or you might develop wart-like growths. Having these medicines can also make your skin more sensitive to the sun. In case of this it’s a good idea to protect your skin by wearing sunscreen, protective clothing and staying in the shade.

You have regular skin checks whilst on this treatment and for several months after.

Let your healthcare team know if you notice any changes to your skin.

Pain in different parts of the body

You might feel some pain in your tummy (abdomen), arms, legs, muscles or joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Muscle spasms

You may feel stiff and have muscle spasms. Let your doctor or nurse know if you have muscle spasms during or after having treatment.

Tiredness and weakness

Tiredness and weakness (fatigue) can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

Talk to your doctor or nurse if this effect is stopping you from doing your usual daily activities.

Swelling in the hands, feet and face

You may have swelling of your face, hands and feet due to a build up of fluid (oedema). 

Liver changes

You might have liver changes that are usually mild and unlikely to cause symptoms. They usually go back to normal when treatment finishes. You have regular blood tests to check for any changes in the way your liver is working.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

  • risk of getting an infection – due to a low number of white blood cells that help fight against infection

  • low levels of red blood cells in your blood (anaemia), this can make you feel weak and tired

  • low levels of platelets – this can increase the risk of bleeding

  • infection such as water infection (urinary tract infection – UTI), deep skin infection (cellulitis) or inflammation of the hair follicles (folliculitis)

  • a different type of skin cancer called squamous cell carcinoma – this is usually removed with surgery

  • loss of fluid in the body (dehydration) – signs include feeling dizzy, not passing much urine, and dark coloured urine

  • low levels of salts (sodium and phosphate) in your blood

  • high blood sugars, symptoms include headaches, feeling thirsty and blurred vision

  • eye problems such as blurred vision, eye pain, flashes of light, floaters (tiny spots that appear in your vision) and redness in your eyes

  • heart problems including a drop in how well the heart pumps blood.Rarely how fast your heart beats (rate) may drop

  • low blood pressure, symptoms include feeling dizzy, lightheaded or you might faint

  • shortness of breath

  • a dry or sore mouth and you may have mouth ulcers

  • sweating more than usual or night sweats

  • hair loss or thinning

  • sore, red and painful hands and feet

  • inflammation of tissue (mucosa) – the mucosa lines a number of different areas in the body such as your mouth, bowel and airways

  • a high level of an enzyme in your blood that can be a sign of injury to muscle, including the heart

Rare side effects

These side effects happen in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:

  • a new primary melanoma skin cancer, this is usually removed with surgery

  • skin tags

  • an allergic reaction – you may get a rash, shortness of breath, redness or swelling of the face

  • inflammation of the lungs (pneumonitis), symptoms include shortness of breath and a cough

  • inflammation of your pancreas, symptoms include severe tummy pain, feeling or being sick, a high temperature or you may have loose poo

  • inflammation of the bowel (colon) causing tummy pain, diarrhoea, fever, blood in your poo

  • kidney problems – your bloods may show your kidneys aren’t working properly, or symptoms might include confusion, not passing enough urine and shortness of breath

  • clumping of cells to make small lumps in your body, often in the lungs (sarcoidosis)

Other side effects

Blood clots that can be life threatening. There isn't enough information to work out how often this might happen with this combination of medicines. Signs are pain, redness and swelling where the clot is. Feeling breathless can be a sign of a blood clot in the lung.

Contact your advice line or doctor straight away if you have any of these symptoms.

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do you need to know?

Other medicines, foods and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Loss of fertility

You may not be able to become pregnant or father a child after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.  .

Pregnancy and contraception

This treatment may harm a baby developing in the womb. It is important not to become pregnant or father a child while you're having treatment w and for at least 4 months afterwards.

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner falls pregnant while having treatment.

This treatment may have an effect on how well hormonal contraceptives work. If you’re taking hormonal contraceptives like the pill, injections or patches you should use additional barrier contraceptives such as condoms.


It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.


Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and one of the shingles vaccines called Zostavax.

You can have:

  • other vaccines, but they might not give you as much protection as usual
  • the flu vaccine (as an injection)
  • the coronavirus (COVID-19) vaccine - talk to your doctor or pharmacist about the best time to have it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system Open a glossary item recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Related links