Temozolomide is a type of chemotherapy. It is also known as Temodal. You might have it as a treatment for a type of brain tumour called malignant (cancerous) glioma. Malignant glioma includes glioblastoma multiforme (GBM) and anaplastic astrocytoma.
How temozolomide works
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 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 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.
When you take temozolomide
You might have temozolomide with radiotherapy or on its own.
Temozolomide with radiotherapy
You usually take temozolomide once a day for between 6 to 7 weeks.
You also have radiotherapy every day, Monday to Friday, during this time. Your doctor will tell you how many radiotherapy treatments you’ll have in total.
Temozolomide on its own
You can have up to 12 cycles of treatment with temozolomide. A cycle of treatment means that you take temozolomide for some days and then have a break to allow your body to recover.
Each cycle of treatment lasts 28 days. You might have each cycle in the following way:
- You take temozolomide once a day
- You don’t have any treatment
You then start a new treatment cycle.
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.
How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having. For example, your side effects could be worse if you're also having other drugs or radiotherapy.
When to contact your team
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
Early treatment can help manage side effects better.
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:
Increased risk of infection
Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.
Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection.
Bruising, bleeding gums or nose bleeds
This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).
Loss of appetite
You might lose your appetite for various reasons when you are having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.
Tell your doctor or nurse 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. Avoiding fatty or fried foods, eating small meals and snacks, drinking plenty of water, and relaxation techniques can all 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 treating it once it has started.
Constipation or diarrhoea
Tell your doctor or nurse 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.
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.
You could lose all your hair. This includes your eyelashes, eyebrows, underarm, leg 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.
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.
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
- an allergic reaction
- 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
- 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
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 severe allergic reaction that can be life threatening
- 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)
- problems with your balance
- 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
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 some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.
Pregnancy and contraception
This drug may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment with this drug and for at least 6 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.
Loss of fertility
You may not be able to become pregnant or father a child 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
Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.
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
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.
Tell your doctor if you have had hepatitis B. This is because temozolomide can cause it to become active again. Your doctor can monitor you during treatment if this is the case.
Driving or operating machinery
Don't drive or operate machinery or tools if you have side effects such as dizziness, tiredness, sleepiness or blurred vision.
More information about this treatment
For further information about this treatment go to the electronic Medicines Compendium (eMC) website.
You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.
This page is due for review. We will update this as soon as possible.