Gliadel® wafers

Gliadel wafers are small discs that contain the chemotherapy drug carmustine. They are used to treat certain types of brain tumours.

What are Gliadel wafers?

Gliadel® wafers are small discs. They are about the size of a five pence (5p) coin. They are sometimes used to treat high-grade brain tumours called gliomas along with surgery or radiotherapy, or both.

How Gliadel wafers are given

The operation is carried out by a neurosurgeon. This is a surgeon who specialises in brain surgery.

The surgeon places the wafers into the area in the brain where the tumour has been removed. Usually, up to eight wafers are used. The wafers release a chemotherapy drug called carmustine directly to the surrounding cells as they dissolve. This usually takes around two to three weeks. They do not need to be removed.

Gliadel wafers may only be suitable in certain situations. Your surgeon will tell you if this treatment may be appropriate for you, before you have your operation. But they may not know if you will be able to have the wafers inserted until you are having your operation. Some people may be given it as part of a clinical trial.

About side effects

Both Gliadel and surgery to remove a brain tumour can cause side effects. Sometimes, it can be difficult to know if a side effect is caused by the Gliadel or the surgery. Your healthcare team will tell you about the possible side effects before your operation.

We explain the most common side effects of this treatment here. We also include some less common side effects. You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

You are unlikely to get all of these side effects. Your healthcare team will talk to you before your operation. They can answer any questions you have about the treatment and the possible side effects.

Always tell your doctor or nurse about any new symptoms you get, or if symptoms get worse. They can give you advice about how to manage these and any drugs that may help. We have more information about side effects of brain surgery.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Possible side effects of Gliadel wafers

Possible effects on the nervous system

These side effects can also happen after surgery to the brain. Your doctors and nurses will monitor you very closely.

Seizures (fits)

You may be more likely to have seizures. This is usually within the first five days after your operation. Your doctor may prescribe medicines for a short time to help prevent them. If you have been having seizures already, you can talk to your surgeon about the medicines you take.

Headaches and dizziness

Headaches and dizziness are common after brain surgery and with Gliadel treatment. Your doctor will tell you which painkillers will help. Tell them if the headaches or dizziness get worse.

Temporary swelling in the brain

This can happen after surgery to the brain and treatment with Gliadel. Your doctor or nurse will usually give you steroids to help reduce this.

Let your doctors or nurse know straight away if you:

  • have headaches (although these are common after surgery), especially if they are severe
  • have any weakness in your arms or legs (on one or both sides) or difficulty walking  
  • become confused, feeling drowsy or sleepy
  • have difficulties with speaking
  • feel sick (nausea) or are sick (vomiting).

If someone with you notices you developing these symptoms, contact the hospital.

Infection in the brain

Your doctors and nurses will be checking you closely for any signs of infection. Tell them if you have:

  • a temperature
  • flu-like symptoms
  • headaches
  • neck stiffness
  • sensitivity to bright light.

Other possible side effects

The following side effects may be related to your surgery, Gliadel or other treatments you are having.

Feeling or being sick

Your doctor can give you anti-sickness drugs to prevent or reduce sickness or vomiting. Take the drugs exactly as your nurse or pharmacist tells you. If the sickness continues, tell your doctor. They can prescribe other anti-sickness drugs that may work better for you.

Skin rash

This treatment may cause a mild skin rash. If this happens, tell your doctor or nurse. They may give you creams or medication to help.

Slow wound healing

It may take longer for your wound to heal after your operation. This is because the Gliadel wafers can affect the healing process. Your doctor or nurse will check your wound regularly. If you notice any leaking from the wound, swelling or redness in the area, tell your doctor or nurse straight away.


This treatment can cause constipation. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread unless there are any restrictions on what you eat.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital for advice. Your doctor can give you drugs called laxatives to help.


If you have diarrhoea, tell your nurse. Try to drink at least 2 litres (3½ pints) of fluids every day. It can help to avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Eye problems

If you have blurred vision or your eyes feel painful, let you doctor know straight away.

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • throbbing pain, redness or swelling in a leg or arm
  • suddenly feeling breathless or coughing
  • sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

A blood clot is serious, but it can be treated with drugs that thin the blood (anticoagulants). Your doctor or nurse can give you more information.

You can help reduce the risk of developing a blood clot by:
  • staying active during treatment
  • drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.

Raised blood sugar levels

Your blood sugar levels may be higher than usual. This may be due to some of the other medicines you are taking after the operation. Your doctor will talk to you about how to manage this.

Lower number of white blood cells

This is rare with Gliadel because not much of the carmustine drug is absorbed into the bloodstream. This means there is less risk of infection than with chemotherapy that goes into a vein. But it can still happen.

Chemotherapy can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

It is important to follow any specific advice your cancer treatment team gives you.

Other information about Gliadel wafers


Doctors do not know if Gliadel wafers can affect your fertility (being able to get pregnant or make someone pregnant). If you are worried about this, you can talk to your doctor before treatment starts.


Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.


You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.

Other medicines

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.


Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.

Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations.

If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines, such as shingles, contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.