Dabrafenib (Tafinlar)

Dabrafenib is a type of targeted cancer drug Open a glossary item called a cancer growth blocker. You might have it as a treatment for:

  • melanoma skin cancer that can’t be removed with surgery or has spread to another area of the body. This is called metastatic or advanced melanoma.
  • stage 3 melanoma skin cancer that has been removed with surgery. The aim is to reduce the risk of the cancer coming back.
  • advanced non small cell lung cancer (NSCLC)

You can only have dabrafenib if your cancer has a change (mutation Open a glossary item) in the BRAF gene Open a glossary item. Your doctor will check for this mutation before you can start this drug.

How does dabrafenib work?

Dabrafenib is a type of cancer growth blocker. It works by targeting certain proteins made by the changed BRAF gene that helps cancer cells to grow. By blocking these proteins, dabrafenib stops or slows down the growth of cancer cells.

How do you have dabrafenib?

You take dabrafenib as a capsule twice a day on an empty stomach. This means that:

• after taking dabrafenib you must wait at least 1 hour before eating or

• after eating you must wait at least 2 hours before taking dabrafenib

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.

You have dabrafenib on its own or with another drug called trametinib.

How often do you have dabrafenib?

You usually take dabrafenib twice a day, morning and evening, 12 hours apart.

For advanced cancer, you take dabrafenib for as long as it is working and the side effects aren’t too bad.

To try and prevent melanoma skin cancer coming back after surgery you take dabrafenib for up to 12 months.


You have regular blood tests, scans and other tests during this treatment.

Your doctor or nurse will explain what tests you need.

What are the side effects of dabrafenib?

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 and chills

You might get a high temperature. Or you might feel cold or start shivering (chills). 

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

Loss of appetite

You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.


Tell your healthcare team if you keep getting headaches. They can give you painkillers to help.


It is important to tell your doctor or nurse if you have a cough. This could be due to an infection, such as pneumonia.

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.


Contact your advice line if you have diarrhoea, such as if you've had 4 or more loose watery poos (stools) in 24 hours. Or if you can't drink to replace the lost fluid. Or if it carries on for more than 3 days.

Your doctor may give you anti diarrhoea medicine to take home with you after treatment. Eat less fibre, avoid raw fruits, fruit juice, cereals and vegetables, and drink plenty to replace the fluid lost.

Skin problems

Symptoms of skin problems can include wart-like growths and thickening of the skin. Less commonly your skin might be more sensitive to the sun, you might develop a rash, dry skin, itching, reddening, or skin tags.

Your doctor will check your skin regularly through treatment.

Let your doctor or nurse know if you’re worried about an area of skin. They might be able to give you something to help.

Hair thinning 

Your hair may thin or you might lose hair in certain areas (patches). You're unlikely to lose all your hair. It usually grows back when you finish treatment. 

Other areas of hair that might be affected include your eyelashes, eyebrows, underarm, leg and sometimes pubic hair.

Soreness, redness and peeling on palms and soles of feet

The skin on your hands and feet may become sore, red, or may peel. You may also have tingling, numbness, pain and dryness. This is called hand-foot syndrome or palmar plantar syndrome.

Moisturise your skin regularly. Your healthcare team will tell you what moisturiser to use.

Arm, leg, joint or muscle pain

You might have aches or pain in your arms, legs, muscles or joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Tiredness and weakness

You might feel very tired and as though you lack energy.

Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.

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


This drug might make you feel dizzy. You might also feel dizzy when standing or moving around. Or it might feel like the world is spinning.

Don’t drive or operate machinery if you have this.

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:

  • types of skin cancer called squamous cell carcinoma and basal cell carcinoma
  • low levels of a type of mineral salt (phosphate) in your blood
  • high blood sugars
  • constipation
  • flu-like symptoms. You might have symptoms such as headaches, aching muscles, a high temperature or runny nose.
  • skin sensitive to sunlight. Cover up or use sunblock when you go out in the sun.

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:

  • another melanoma skin cancer
  • an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness. Some allergic reactions can be life threatening, alert your nurse or doctor if notice any of these symptoms.
  • inflammation of the eye. This can cause blurred vision, eye pain, redness in your eye, changes in vision, and flashes of light.
  • inflammation of your pancreas. You might get severe tummy pain, feel or be sick, a high temperature or diarrhoea.
  • kidney problems. Your blood test results may show your kidneys aren’t working properly. You might have symptoms including confusion, not passing enough urine or shortness of breath.

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.


It is not known whether this treatment affects fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Pregnancy and contraception

This drug may harm a baby developing in the womb. It is important not to become pregnant while you are having treatment with this drug and for at least 4 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.

If you’re taking hormonal contraceptives like the pill, injections or patches you should use an additional barrier contraceptive such as a condom. It’s not known if dabrafenib affects the way hormone contraceptives work.


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.

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