Temozolomide (Temodal)

Temozolomide is a type of chemotherapy. It is also known as Temodal.

It is a treatment for:

  • certain types of brain tumour such as glioblastoma and astrocytoma
  • neuroendocrine tumours
  • adrenal gland Open a glossary item cancer

You pronounce temozolomide as teh-moh-zol-oh-mide.

How does temozolomide work?

Temozolomide works by stopping cancer cells from making DNA. DNA stands for DeoxyriboNucleic Acid. It is the genetic material of a cell. 

If the cancer cells can't make DNA, they can't split into 2 new cells, so the cancer can't grow.

How do you have temozolomide?

Temozolomide comes as a capsule that you take once a day. You should take it at the same time each day.

You should swallow the capsule whole with a glass of water and on an empty stomach. For example, you can take the capsule an hour before you plan to eat a meal.

Taking your capsules

You must take capsules 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 have temozolomide?

You have temozolomide as cycles of treatment. This means that you have the drug then a rest to allow your body to recover.

Temozolomide for a brain tumour

You might have temozolomide on its own or with radiotherapy.

Temozolomide on its own

You can have up to 12 cycles of treatment with temozolomide.

Days 1 to 5
  • You take temozolomide once a day.
Days 6 to 28
  • You don’t have any treatment.

You then start a new treatment cycle.

Temozolomide with radiotherapy 

You usually take temozolomide once a day for 6 weeks.

Temozolomide for a neuroendocrine tumour or adrenal gland cancer

You take temozolomide for as long as it’s working, and the side effects aren’t 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.

What are the side effects of temozolomide?

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 (10%). You might have one or more of them. They include:

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.

Feeling and 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.

Constipation or diarrhoea 

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


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.

Seizures (fits)

Tell your doctor if you have any fits, twitching or jerking of your limbs. 

Weakness on one side of the body

Tell your doctor or nurse if you have this. 

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. 

Skin rash 

A rash can also be itchy. Tell your doctor or nurse if you have a skin rash. They can prescribe medicine to stop the itching and soothe your skin.

Problems with your speech

You might have loss of speech or problems understanding written or spoken words.

Occasional side effects

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

  • a drop in the levels of red blood cells which can cause breathlessness and looking pale (anaemia)
  • Increased risk of getting an infection due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. Infections can sometimes be life threatening.
  • an allergic reaction - rarely this can be life threatening
  • red and swollen face
  • high blood sugar levels
  • confusion, anxiety and memory loss
  • low mood (depression)
  • difficulty sleeping
  • shaking (tremor)
  • sleepiness and dizziness
  • numbness or tingling usually in your fingers and toes
  • difficulty speaking and concentrating
  • difficulty breathing and cough
  • pain in different parts of your body such as your back, muscles, joints and tummy (abdomen)
  • fever and flu like symptoms
  • feeling unwell
  • taste changes
  • oral thrush
  • hearing changes such as ringing in your ears (tinnitus) and hearing loss
  • blurred vision and eye pain
  • difficulty swallowing or a sore throat
  • indigestion or heartburn
  • difficulty controlling your bladder (incontinence)
  • a build up of fluid in your arms and legs
  • weight changes – you might gain or lose weight
  • liver changes that are usually mild and unlikely to cause any problems
  • problems with balance or coordination
  • bleeding or a blood clot
  • high blood pressure
  • tummy (abdominal) pain
  • radiation injury - if you’re having temozolomide with radiotherapy for a brain tumour, there is a risk of damage to the brain tissue. Your doctor will discuss this with you.

Rare side effects

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

  • a small risk of developing another cancer some years after treatment such as leukaemia
  • changes to the levels of minerals and salts in your body
  • seeing or hearing things (hallucinations)
  • brain infections which can be fatal
  • behavioural changes
  • palpitations
  • wound infections
  • reactivated hepatitis B infection
  • hot flushes
  • difficulty controlling your bowels
  • pain when passing urine
  • severe liver problems that can be life threatening
  • increased sweating
  • skin sensitivity to sunlight
  • a severe skin reaction that may start as tender red patches which leads to peeling or blistering of the skin. You might also feel feverish and your eyes may be more sensitive to light. This is serious and could be life threatening
  • breast pain
  • feeling thirsty or a dry mouth
  • diabetes
  • piles (haemorrhoids)
  • blocked nose
  • changes to the lung tissue that can cause cough and breathlessness – rarely this can be life threatening
  • face swelling (oedema)
  • changes to the colour of your tongue
  • vaginal itching or bleeding
  • problems with your teeth
  • shivering

Coping with side effects

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

What else do I need to know?

Other medicines, foods and drinks

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.

Pregnancy and contraception

This drug may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment with this drug and for at least 6 months after treatment.

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.

Loss of fertility

You may not be able to become pregnant or get someone pregnant 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.    


Don’t breastfeed during this treatment because the drug may come through into your breast milk.

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