Vemurafenib (Zelboraf)

Vemurafenib is a type of targeted cancer drug called a cancer growth blocker. It is a treatment for melanoma skin cancer that:

  • can’t be removed with surgery
  • has spread to another area of the body (advanced or metastatic melanoma)

You can only have vemurafenib if you have a BRAF gene change Open a glossary item (mutation). Your doctor tests tissue from your cancer to check for this mutation. 

How does vemurafenib work?

About half of all melanomas have a change in the BRAF gene, which means the cells make too much BRAF protein. This protein makes the cancer cells grow and divide.

Vemurafenib works by targeting this protein and so slows down or stops cancer cells developing.

How do you take vemurafenib?

You take vemurafenib as tablets.

You swallow the tablets whole with a glass of water. Do not chew or crush the tablets.

You can take vemurafenib with or without food. But do not take vemurafenib regularly on an empty stomach.

Taking your tablets

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

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

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

How often do you take have vemurafenib?

You take vemurafenib twice a day, morning and evening.

You usually keep taking it for as long as it’s working or until the side effects get too bad.


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 also have an electrocardiogram (ECG) before and during this treatment. It checks for any changes to your heart rate and rhythm. It lets your doctor know how well your heart is working.  

What are the side effects of vemurafenib?

Side effects can vary from person to person. They also depend on what other treatment you are having. 

When to contact your team

Your doctor, pharmacist or nurse will go through the possible side effects. They will monitor you closely 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

  • the side effects are affecting your daily life

Early treatment can help manage side effects better. 

Contact your advice line, doctor or nurse immediately if you have signs of infection, such as a temperature above 37.5C or below 36C, or if you develop a severe skin reaction. Signs of a severe skin reaction include peeling or blistering of the skin.

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 (fever)

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

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.


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

Taste changes

Taste changes may make you go off certain foods and drinks. You may also find that some foods taste different from usual or that you prefer to eat spicier foods. Your taste gradually returns to normal a few weeks after your treatment finishes.


You may get a cough while you are having treatment. Tell your healthcare team if you have a cough.

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

Skin problems can include a rash, dry skin, itching, and reddening of the skin. Your skin might feel thicker or look crusty, scaly or have small raised bumps on the surface.

Your skin might also be more sensitive to the sun and at risk of severe sunburn. It's a good idea to protect your skin with clothing, sunscreen and the shade.  

Rarely, vemurafenib can cause a severe skin reaction. This usually starts with a high temperature and flu-like symptoms, it then leads onto skin blistering and peeling.

Your doctor will check your skin regularly throughout your treatment. Let them know if you’re worried about an area of skin. They might be able to give you something to help.

Skin cancer

There is a risk of developing a type of skin cancer called squamous cell carcinoma. Your doctor checks your skin regularly during treatment and up to 6 months afterwards.

There is also a risk of developing another melanoma or a different type of skin cancer called basal cell carcinoma. But these happen less often.

Tell your healthcare team if you notice any skin changes.

Non cancerous growths

There is a risk of developing non cancerous (benign) growths or tumours while taking this drug. For example, keratocanthoma, seborrheic keratosis or skin papilloma.

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.

Hair loss

You could lose all your hair. This includes your eyelashes, eyebrows, underarms, legs and sometimes pubic hair. Your hair will usually grow back once treatment has finished but it is likely to be softer. It may grow back a different colour or be curlier than before. 


You might feel pain in different areas of your body such as your arms, legs, muscles, back, joints or bones.

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.

Swelling of your legs and arms

Swelling of legs and arms is due to fluid build up. This is called peripheral oedema. Let your doctor or nurse know if you have any swelling.

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 low numbers of white blood cells Open a glossary item which help fight against infection
  • inflammation of your hair roots (folliculitis)
  • weakness or lack of movement on one side of your face (Bell’s palsy) – this is usually reversible
  • feeling of tingling, numbness, pain or weakness in your hands and feet
  • eye problems such as inflammation of the eye. You might have painful eyes, blurred vision, be sensitive to light, see spots or shadows in your vision. Rarely, vemurafenib can cause a blockage of the blood supply to your eye. Tell your doctor straight away if you have any changes
  • inflammation of your blood vessels. Symptoms can vary depending on which blood vessels are affected. General symptoms include feeling very tired, loss of appetite, weight loss, a high temperature, and aches and pains
  • inflammation of your joints (arthritis)
  • liver problems, that are usually picked up on blood tests. Rarely, your liver can get injured from vemurafenib stopping it from working properly. You have regular blood tests to check for changes to the liver
  • kidney problems – your blood tests might show changes to how well your kidneys are working
  • changes to the rhythm or activity of your heart – you have a heart trace (ECG) before and during treatment to check this
  • weight loss
  • worsening of radiotherapy side effects

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:

  • an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness
  • an increased risk of another type of cancer, such as squamous cell cancers, chronic myelomonocytic leukaemia (CMML) and pancreatic cancer
  • inflammation of the pancreas, symptoms include severe tummy pain, feeling or being sick, a high temperature or you may have loose poo
  • your little or ring finger bending in towards your palm (Dupuytren’s contracture)
  • clumping of cells to make small lumps in your body, often in the lungs, eyes and skin (sarcoidosis)
  • thickening of the deep tissues underneath the soles of the feet (plantar fascial fibromatosis)

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

It is not known whether this treatment affects fertility Open a glossary item 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 treatment may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you're having treatment and for at least 6 months afterwards.

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

Tell your doctor if you’re taking a hormonal contraceptive such as the pill, patches or injections. This drug might reduce how well they work so you should also use a barrier contraceptive like a condom.


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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