It can be difficult to treat brain tumours with chemotherapy drugs because the body has a protection system known as the blood–brain barrier. This guards the brain from harmful substances that may be circulating in the blood, such as germs or chemicals. Only certain types of chemotherapy drugs can get through this barrier. Temozolomide is the most commonly prescribed chemotherapy drug for the treatment of brain tumours, although other chemotherapy drugs are also used.

You may be given chemotherapy as capsules or tablets that you swallow, or as a liquid through a drip inserted into your vein (intravenously). Each treatment session is usually followed by a rest period of a few weeks.

The way your body reacts to chemotherapy will be monitored through regular blood tests. Your treatment schedule may change when your doctor sees how you are responding to the drugs.

There are many possible side effects of chemotherapy, depending on the type of drugs you are given. Side effects may include:

• increased risk of infection
• nausea, vomiting or loss of appetite
• tiredness, fatigue and lack of energy
• mouth sores and ulcers, skin rash
• diarrhoea or constipation
• breathlessness due to low levels of red blood cells (anaemia)
• the feeling of pins and needles and numbness (nerve damage known as peripheral neuropathy)
• damage to ovaries or testicles, which can make you unable to have children naturally (infertile).

It is rare to lose all your hair with the drugs used to treat brain and spinal cord tumours, although in some cases your hair may become thinner. For more information, see Chemotherapy.

Find out more about the different kind of drug therapies that may be used to treat brain cancer, such as chemotherapy, steroid therapy, and anti-convulsant medication.