Cancer drugs A to Z list
Dacomitinib is a type of targeted cancer drug. You pronounce it as da-koh-mih-tih-nib.
You might have dacomitinib for or non small cell lung cancer (NSCLC) that hasn’t had treatment.
Find out more about treatment for NSCLC
Dacomitinib is a which is a type of cancer growth blocker. It blocks proteins on cancer cells that encourage the cancer to grow. So this can help slow down or stop the cancer growing.
These proteins are called epidermal growth factor receptors (EGFR). If you have a cancer that has these receptors, you are EGFR positive. You have tests on your cancer cells to check for these receptors before you have this treatment.
Read more about cancer growth blockers
Dacomitinib is a tablet. You swallow it whole with a glass of water. You can take it with or without food.
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.
You take dacomitinib once a day, every day, at the same time each day.
You usually take dacomitinib for as long as the treatment is working and you are not experiencing too many side effects.
You have blood tests before and during your treatment. They check your levels of and other substances in the blood. They also check how well your liver and kidneys are working.
Before treatment starts you may have a blood test to check for viruses such as hepatitis B, hepatitis C, and HIV. This is called a viral screen.
It’s important for your doctor to know if you have had any of these viruses. This is because this treatment can weaken your and can cause the virus to become active again (reactivation).
Side effects can vary from person to person. They also depend on what other treatment you are having.
Your doctor, nurse, or pharmacist 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
We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.
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.
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. Tell your doctor or nurse if you have ulcers.
You might not feel like eating and may lose weight. Eating several small meals and snacks throughout the day can be easier to manage. You can talk to a dietitian if you are concerned about your appetite or weight loss.
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. For example, in one day you have 2 or more loose bowel movements than usual. If you have a , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.
Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain . But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables.
Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.
Your nails may become brittle, dry, painful, change colour or develop ridges. The nails may break, split or separate from the nail bed. The skin around your nail might get swollen, red and sore (paronychia). It may also become infected.
Talk to your healthcare team if you develop any nail changes.
This treatment can cause skin problems. Symptoms can include a skin rash, dry skin, acne, itching, cracked and peeling skin.
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 products you can use on your skin to help.
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.
Your blood contains different levels of minerals, electrolytes, and proteins. This treatment can cause the level of potassium in your blood to drop. You will have regular blood tests to check for this.
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.
You might get dry, red and itchy eyes (conjunctivitis).
Less commonly you might have inflammation of the dome shaped tissue in the front of the eye (cornea). Some of the symptoms can include redness, pain, watery eyes, blurred vision, loss of some vision, sensitivity to light and like something is stuck in the eye.
Tell your healthcare team if you have eye problems. They can give you eye drops or other medication to help.
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.
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:
taste changes
extra hair growth on your body
loss of body fluid (dehydration)
inflammation and scarring of the lungs - symptoms include shortness of breath, difficulty breathing, a cough and high temperature
We have more information about side effects and tips on how to cope with them.
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We do not list these interactions on this page. 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 if you have any other medical conditions or allergies.
It is not known whether this treatment affects in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
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 17 days afterwards.
Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you fall pregnant while you're having treatment.
It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
Do not have live vaccines while you’re having treatment and for up to 12 months afterwards. For some people, it may be longer than this. The length of time you need to avoid live vaccines depends on the treatment you’ve had.
Ask your doctor or pharmacist how long you should avoid live vaccinations.
In the UK, live vaccines include rubella, mumps, measles, chickenpox, BCG, and yellow fever. You can usually have non-live vaccines. But they might not give you as much protection as usual. These include the:
flu vaccine, as an injection
coronavirus (COVID-19) vaccine
Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.
You can be in contact with other people who have had live vaccines as injections. If someone has had a live vaccine by mouth or nasal spray there may be a small risk the vaccine virus can be passed onto you if your is weakened.
Your healthcare team will let you know if you need to take any precautions if you are in close contact with someone who has had a live vaccine.
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 and Healthcare products Regulatory Agency (MHRA) as part of their Yellow Card Scheme.
Last reviewed: 07 Oct 2026
Next review due: 07 Oct 2029
Lung cancer starts in the windpipe (trachea), the main airway (bronchus) or the lung tissue. Cancer that starts in the lung is called primary lung cancer.
Cancer drugs have side effects and these can vary from person to person. But there are things that you can do to help you cope.
A team of health professionals decides what treatment you might need. They also decide what treatment options you have. The type of treatment you have for non small cell lung cancer will depend on the stage of your cancer.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
