Gliadel® wafers are small discs that contain the chemotherapy drug carmustine. They are used to treat certain types of brain tumour.
Gliadel® wafers are small discs that contain the chemotherapy drug carmustine. They are about the size of a 5 pence (5p) coin. They are sometimes used to treat a type of brain tumour called a glioma. They are used along with surgery or radiotherapy, or both. It is best to read this information with our information about chemotherapy for brain tumours and the type of brain tumour you have.
Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.
You have a small operation to place Gliadel wafers in the area where the brain tumour was removed. The operation is done by a surgeon who specialises in brain surgery (neurosurgeon).
Usually, up to 8 wafers are used. The wafers release a chemotherapy drug called carmustine directly to the surrounding cells. This usually takes around 2 to 3 weeks. As they release the drug, the wafers dissolve. This means they do not need to be removed.
Gliadel wafers may only be suitable in certain situations. Your surgeon will tell you whether they are suitable for you before your operation. But your surgeon may not know whether they can insert the wafers until you are having your operation. Some people are given Gliadel wafers as part of a clinical trial.
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.
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.
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 effects on the nervous system
Gliadel wafers may have some effects on the nervous system. This can also happen after surgery to the brain. Your doctors and nurses will monitor you very closely.
You may be more likely to have seizures (fits). They are most likely to happen within the first 5 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
Gliadel wafers may cause swelling in the brain. This is usually temporary. It can also happen after surgery to the brain. Your doctor or nurse will usually give you steroids to help reduce swelling.
Tell your doctors or nurse straight away if you:
- have severe headaches
- feel weak in your arms or legs (on one or both sides)
- become confused, feeling drowsy or sleepy
- have difficulty walking
- feel confused, drowsy or sleepy
- have difficulty speaking
- feel sick (nauseas) or are sick (vomit).
If someone with you notices you have these symptoms, they should contact the hospital straight away.
An 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
- neck stiffness
- sensitivity to bright light.
Risk of infection
This treatment 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 sometimes called neutropenia.
An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given 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
- your temperature goes below 36°C (96.8°F).
Symptoms of an infection include:
- feeling shivery and shaking
- a sore throat
- a cough
- needing to pass urine (pee) a lot, or discomfort when you pass urine.
It is important to follow any specific advice your cancer treatment team gives you.
The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time, until your cell count increases.
This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. 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.
- 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.
This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.
If you have diarrhoea:
- try to drink at least 2 litres (3½ pints) of fluids each day
- avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
- contact the hospital for advice.
This treatment may affect your skin. It may cause a rash, which might be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.
Always tell your doctor or nurse about any changes to your skin. They can give you advice and may prescribe creams or medicines to help. Skin changes usually improve when treatment finishes.
This treatment can affect your eyes and eyesight. If you have any of these symptoms during treatment or after it finishes, contact your doctor straight away:
- sore or swollen eyes
- changes to your eyesight.
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.
Lower number of white blood cells
This treatment can reduce the number of white cells in your blood. These cells fight infection. This is rare with Gliadel wafers 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. Tell your doctor or nurse if you have any signs of an infection.
Symptoms of an infection include:
- a cough
- a sore throat
- needing to pass urine (pee) often or not passing urine.
Contact your doctor or the hospital straight away if:
- your temperature goes over 37.5°C (99.5°F)
- your temperature goes below 36.5°C (96.8°F)
- you suddenly feel unwell, even with a normal temperature.
Raised blood sugar levels
This treatment may raise your blood sugar levels. You will have regular blood tests to check this. Symptoms of raised blood sugar include:
- feeling thirsty
- needing to pass urine (pee) more often
- feeling tired.
Tell your doctor or nurse if you have these symptoms during treatment or after it finishes.
If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this.
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.
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.
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.
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.
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