This page tells you about a chemotherapy drug called temozolomide and its possible side effects. There is information about
Temozolomide is a chemotherapy drug used to treat brain tumours. It is a type of drug known as an alkylating agent and works by stopping cancer cells from making new DNA. DNA stands for DeoxyriboNucleic Acid. It is the genetic material of a cell. If cancer cells can't make DNA, they can’t split into 2 new cells, so the cancer can't grow.
You take temozolomide as capsules that you swallow whole with a glass of water. Take them on an empty stomach – for example, 1 hour before or after meals. Store the capsules in a safe place away from children and return any unused capsules to your pharmacy.
You may have temozolomide alongside radiotherapy for newly diagnosed brain tumours. You have radiotherapy for 6 to 7 weeks and you take the temozolomide capsules each day during this time. It is best to take them at the same time each day. If you have temozolomide together with radiotherapy you are at higher risk of getting a type of lung infection called pneumocystis carinii pneumonia, so your doctor will prescribe medicines to help protect you against this.
After the radiotherapy, or if you have a brain tumour that has come back, you may have temozolomide as a course of cycles of treatment. You take the temozolomide capsules for 5 days every 4 weeks. You may repeat this treatment up to 6 times.
It is very important that you take capsules according to the instructions your doctor or pharmacist gave you. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.
If you accidentally take more temozolomide capsules than you were told to, contact your doctor, pharmacist or nurse straight away.
If you forget to take a dose of temozolomide take the missed dose as soon as possible during the same day. If more than a full day has gone by, check with your doctor. Don't take a double dose to make up for a forgotten dose, unless your doctor tells you to do that.
Temozolomide side effects are listed below. You can use the links to find out more about each side effect. Or you can go to the cancer drug side effects section for general information. The side effects may be different if you are also having other cancer drugs.
If you are taking temozolomide alongside radiotherapy you may also have side effects from the radiotherapy.
More than 10 in every 100 people have one or more of the side effects listed below.
- An increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, a sore throat, pain passing urine, or you may feel cold and shivery. If you have a severe infection this can be life threatening. Contact your treatment centre straight away if you have any of these effects or if your temperature goes above 38°C. You will have regular blood tests to check your blood cell levels
- Tiredness and breathlessness due to a drop in red blood cells (anaemia) – you may need a blood transfusion
- Bruising more easily due to a drop in platelets – you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia)
- Fatigue (tiredness) during and after treatment – most people find their energy levels are back to normal within 6 months to a year
- Feeling or being sick can start within a couple of hours of having the capsules and may last until the next day – take anti sickness medicines regularly and tell your doctor or nurse if they aren't working, as there will be others you can try
- Loss of appetite
- Taste changes
- Anxiety and difficulty sleeping
- Constipation – drink plenty of fluids and tell your doctor or nurse if it doesn't get better within a few days
- Women may stop having periods (amenorrhoea) but this may only be temporary
- Loss of fertility may happen with this drug – you may not be able to get pregnant or father a child after treatment so talk to your doctor before starting treatment if you plan to have a baby in the future. It may be possible for men to store sperm beforehand
Between 1 and 10 in every 100 people have one or more of these.
- An itchy rash and dry skin
- A high temperature (fever) and chills – this does not usually last for long
- Hair loss – you may have some thinning within a month of starting treatment but your hair will grow back when the treatment is over
- Liver changes – you will have regular blood tests to check how well your liver is working
- A higher risk of blood clots – let your doctor or nurse know if you have any area of pain, redness or swelling that feels warm to the touch
- Muscle weakness or back pain
- Weight loss
- Diarrhoea – drink plenty of fluids and tell your doctor or nurse if it doesn't get better within a few days
- Abdominal pain and an upset stomach
The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on
- How many times you've had the drug before
- Your general health
- The amount of the drug you have (the dose)
- Other drugs you are having
Coping with side effects
Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.
Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies. Some drugs can react together.
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 and for at least 6 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.
Do not breastfeed during this treatment because the drug may come through in the breast milk.
You should not have immunisations with live vaccines while you are having chemotherapy or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG, yellow fever and Zostavax (shingles vaccine).
You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your chemotherapy. It is safe to have the flu vaccine.
It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.
This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at www.medicines.org.uk.
If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at www.mhra.gov.uk.
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