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Side effects of dabrafenib (Tafinlar)

Find out about the side effects of the cancer drug dabrafenib.

Tell your doctor or nurse if you have any side effects so they can help you manage them. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Contact your doctor or nurse immediately if any of your side effects get severe or if you have signs of infection, including a temperature above 38C.

The side effects may be different if you are having dabrafenib with other cancer treatments.

Common side effects

Each of these effects happens in more than 1 in 10 people (10%). You might have one or more of them.

You might have a:

  • rash
  • red, dry, itchy skin
  • small wart like growths
  • small outgrowths of skin (skin tags)

Tell your doctor if any of these happen.

Don't go swimming if you have a rash because the chlorine in the water can make it worse.

Check with your doctor or nurse before using any creams or lotions. Wear a high factor sun block if you’re going out in the sun.

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

Tell your doctor or nurse straight away if you have pain, swelling, redness or tingling of your hands or feet.


  • Take medicines that your doctor or nurse can prescribe.
  • Keep your hands and feet cool.
  • Avoid very hot water.
  • Don’t wear tight fitting gloves or socks.
  • Moisturise your skin with non perfumed creams.

Your skin may become thicker or harder. 

Let your doctor or nurse know if you have headaches. They can prescribe a mild painkiller such as paracetamol for you.

Feeling or being sick can start a few hours after treatment and last for a few days. Anti sickness injections and tablets can control it. Tell your doctor or nurse if you feel sick. You might need to try different anti sickness medicines to find one that works.

Contact your doctor or nurse straight away if you’ve been sick more than once in a day.


  • Avoid eating or preparing food when you feel sick.
  • Avoid foods that are fried, fatty, or have a strong smell.
  • Drink plenty of liquid to stop you from getting dehydrated.
  • Relaxation techniques help control sickness for some people.
  • Ginger can help – try it as crystallised stem ginger, ginger tea or ginger ale.
  • Fizzy drinks help some people when they’re feeling sick.

Tell your doctor or nurse if you have diarrhoea. They can prescribe medicine to help you. 

Drink at least 2.5 litres of fluid a day. This helps to keep you hydrated.

Ask your nurse about soothing creams to apply around your back passage (rectum). The skin in that area can get very sore and even break if you have severe diarrhoea.

Contact your doctor or nurse immediately if you have diarrhoea 4 or more times a day, or any diarrhoea at night.

You might not feel like eating and may lose weight. It is important to eat as much as you can.


  • Eating several small meals and snacks throughout the day can be easier to manage.
  • Ask your doctor to recommend high calorie drinks to sip between treatments if you are worried about losing weight.
  • Eat whatever you feel like eating rather than what you think you should eat.
  • Make up calories between treatments for the days when you really don’t feel like eating.
  • Drink plenty of fluids even if you can't eat.
  • Don't fill your stomach with a large amount of liquid before eating.
  • Try to eat high calorie foods to keep your weight up.
Talk to your dietitian about having high calorie drinks to boost your calorie intake if you need them.

You might feel tired during the treatment. You might also feel weak and lack energy.

It can sometimes help to sleep for a short time during the day. Rest when you need to.

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.

If you get a high temperature, let your doctor or nurse know straight away. Ask them if you can take paracetamol to help lower your temperature.

Let your doctor or nurse know if you have pain anywhere during or after having treatment. There are lots of ways to treat pain, including relaxation and painkillers.

It is important to tell your doctor or nurse if you have a cough. This could be due to an infection, such as pneumonia. Or it could be caused by changes to the lung tissue, making it less flexible.

For example, you might have blurred vision or reddening (infalmmation) of the white part of the eye. Tell your doctor or nurse straight away if you have any changes to your eyes.

Don't drive or operate machinery if you have eyesight changes.

You could lose all your hair or it may become thinner. Your hair will grow back once treatment is finished. Your hair is likely to be softer when it grows back. It can also grow back a different colour or be curlier than before.


  • ask about getting a wig before you start treatment so you can match the colour and texture of your real hair.
  • you could choose a wig for a whole new look.
  • think about having your hair cut short before your treatment starts.
  • some people shave their hair off completely so they don't have to cope with their hair falling out.
  • wear a hairnet at night so you won't wake up with hair all over your pillow

You might have chills. Let your doctor know if you have this. They may be able to prescribe medicines to help. 

Your skin is more sensitive to sunlight during your treatment and for several months afterwards. You need to cover up and stay in the shade. Use a high factor sunscreen if you go out in the sun.

Occasional side effects

Each of these effects happens in more than 1 in 100 people (1%). You might have one or more of them.

Constipation is easier to sort out if you treat it early. Drink plenty of fluids and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking.

Tell your doctor or nurse if you are constipated for more than 3 days. They can prescribe a laxative.

This can happen a few hours after treatment. It might include headaches, muscle aches (myalgia), a high temperature and shivering. Tell you doctor and check whether you can take paracetamol.

You have regular blood and urine tests to check this. Let your doctor or nurse know if you feel thirsty or need to pass urine a lot.

If you have diabetes you may need to check your blood sugar levels more often than usual. 

Heart problems include changes to how your heart works. This can cause changes to your heart rhythm and your ankles can swell.

Tell your doctor or nurse straight away if you have any chest pain.

Your doctor might ask you to have tests to check your heart, such as an electrocardiogram (ECG).

You might develop new skin cancers, including squamous cell cancers, basal cell cancers and melanoma. 

Tell your doctor if you notice any skin changes.

You may have changes in levels of minerals and salts in your blood, including high levels of phosphorus. You won't usually have any symptoms from this. You have regular blood tests during treatment to check this.

Let your doctor or nurse know straight away if you:

  • have sudden headaches
  • feel dizzy
  • have dark poo (faeces)
  • have blood in your urine
  • have tummy (abdominal) pain
  • cough up blood

Rare side effects

Each of these effects happens in fewer than 1 in 100 people (1%). You might have one or more of them.

Some drugs can affect the way your kidneys work. You'll have regular blood tests to check how well your kidneys are working.

You are unlikely to notice any symptoms from this and any changes will almost certainly go back to normal after treatment. 

Stomach pain can be caused by inflammation of your pancreas (pancreatitis). 

Let your doctor know if you have strong tummy (abdominal) pain.

This might include redness, irritation, pain, floating spots before your eyes and sensitivity to light. Let your doctor or nurse know if you have any of these. 

About dabrafenib (Tafinlar)

More information about this treatment

We haven't listed all the very rare side effects of this treatment. For further information see the electronic Medicines Compendium (eMC) website.

You can report any side effect you have that isn’t listed here to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Information and help

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