What is asparaginase?

Asparaginase is used to treat acute lymphoblastic leukaemia (ALL). It may sometimes be used to treat other cancers. It is best to read this information with our general information about chemotherapy and the type of cancer you have. Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

How asparaginase is given

You will usually be given asparaginase during a stay in hospital. A chemotherapy nurse will give it to you. Asparaginase can be given in combination with other cancer drugs.

During treatment you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at safe level to have chemotherapy.

You will see a doctor or nurse before you have chemotherapy. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready.

Your nurse may give you anti-sickness (anti-emetic) drugs before the chemotherapy. The chemotherapy drugs can be given in one of the following ways:

  • into a muscle (intramuscular injection)
  • through a short, thin tube the nurse puts into a vein in your arm or hand (cannula)
  • through a fine tube that goes under the skin of your chest and into a vein close by (central line)
  • through a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line)
  • under the skin (subcutaneous injection).

Your course of chemotherapy

You usually have a course of several cycles of treatment over a few months. Your nurse or doctor will discuss your treatment plan with you.

About side effects

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.

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.

Side effects while treatment is being given

Some people may have side effects while they are being given the chemotherapy or shortly after they have it:

Allergic reaction

Some people have an allergic reaction while having this treatment. Signs of a reaction can include:

  • feeling hot or flushed
  • a skin rash
  • itching
  • shivering
  • feeling dizzy
  • a headache
  • feeling breathless
  • swelling of your face or mouth
  • pain in your back, tummy or chest.

Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly.

Sometimes a reaction can happen a few hours after treatment. If you get any signs or feel unwell after you get home, contact the hospital straight away.

Pain along the vein

You may get pain at the place where the injection is given or along the vein. If you feel pain, tell your nurse or doctor straight away so that they can check the site. They may give the drug more slowly or flush it through with more fluid to reduce pain.

Common side effects

Swollen pancreas (pancreatitis)

Asparaginase can cause a swollen pancreas (pancreatitis). Tell your doctor straight away if you get sharp pain in the upper tummy (abdomen) with sickness and vomiting. They will examine your tummy and prescribe medicines that can help.

Changes in the way the liver works

This treatment may affect how your liver works. This is usually mild and goes back to normal after treatment. You will have blood tests to check how well your liver is working.

Blood clotting

The liver makes proteins that help blood to clot. Asparaginase can cause too many or too few of these proteins to be made.

Too many clotting proteins can cause a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain.

If you have any of these symptoms, contact a doctor straight away.

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

Too few clotting proteins can cause bruising or bleeding. Tell your doctor if you notice any bruising or bleeding.

Diarrhoea

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 (31/2 pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
  • contact the hospital for advice.

Feeling tired

Feeling tired is a common side effect. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.

Headaches

This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.

Feeling sick

You may feel sick in the first few days after this treatment. Your doctor will give you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids and eat small amounts often. If you continue to feel sick, or if you vomit more than once in 24-hours, contact the hospital as soon as possible. They will give you advice and may change the anti-sickness drug to one that works better for you.

Loss of appetite

This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Skin changes

This treatment may affect your skin. It can cause a rash, which may 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 skin changes or if they get worse. They can give you advice and may prescribe creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.

Effects on the nervous system

This treatment can affect the nervous system. You may feel drowsy or confused, dizzy or unsteady. Tell your doctor or nurse straight away if you notice any of these symptoms. They may make some changes to your treatment if they become a problem for you. It is important not to drive or operate machinery if you notice these effects. Rarely, this treatment can cause seizures (fits).

Less common side effects

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • a fever (high temperature)
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

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.

Risk of infection

Rarely, asparaginase 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.

The number of white blood cells will usually return to normal before your next treatment.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. 

Tell your doctor if you have any bruising or bleeding that you cannot explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Some people may need a drip to give them extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Other information

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.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment and for some time afterwards. The drugs may harm the developing baby. It is important to use effective contraception.

Speak to your doctor if you use oral contraception. They may advise you to change to a different type of contraception. This is because some types of asparaginase may interact with oral contraception.

Breastfeeding

Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Sex

If you have sex in the first few days after chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluids.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that 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.

Glucose

Some forms of asparaginase contain glucose (sugar). Talk to your doctor about this if you are diabetic.

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