Asparaginase (Crisantaspase, Erwinase)

Asparaginase is a chemotherapy drug used to treat acute lymphoblastic leukaemia (ALL). One form is made from a type of bacteria called escherichia coli. Another form of asparaginase is made from Erwinia chrysanthemi bacteria and is called crisantaspase. Asparaginase is an enzyme that breaks down a chemical in tumour cells. The tumour cells need this chemical to make protein to create new cancer cells.

You may have asparaginase as an injection into a vein (IV). But you are more likely to have it as a series of injections into a muscle in your arm or leg (IM).

You usually have this type of chemotherapy as a course of cycles of treatment. The exact treatment plan depends on which cancer you are being treated for. You can find out more about the way chemotherapy treatment is planned in the CancerHelp UK section about planning chemotherapy.

The side effects associated with asparaginase are listed below. You can use the links (underlined) to find out more about each side effect. Where there is no link please see our cancer drugs side effects section or use the search box at the top of the page.

Many people have one or more of the following side effects

• 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 is usually mild but affects 2 out of 3 people - it is usually well controlled with anti-sickness medicines
• 2 out of 3 people treated have high temperatures (fever) and chills
• Bruising more easily due to a drop in platelets happens to 1 in 2 patients (50%) - 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). Tell your doctor if you have any of these effects and do not take aspirin - it can increase the risk of bleeding.
• Asparaginase can also cause an increased risk of getting blood clots (thrombosis) in some people.
• Loss of appetite
• This drug may be harmful to a developing baby so it is not advisable to get pregnant or father a child if you are having this drug. You should talk about contraception with your doctor before having the treatment.
• Loss of fertility - we don’t know exactly how this drug affects fertility so do talk with your doctor before starting treatment if this is important to you
• Liver changes that are very mild and unlikely to cause symptoms – the liver will almost certainly go back to normal when treatment is finished, but you will have regular blood tests to check how well your liver is working
• Allergic reaction happens to 1 in 4 (25%) people and you will have a test dose before your treatment to check for this. The reaction is usually mild, causing an itchy rash. But it can sometimes be severe with difficulty breathing and a sudden drop in blood pressure, which will make you feel faint. Tell your nurse immediately if you have these symptoms.

Some people have the following side effects

• Rise in blood sugar - this can make you feel thirsty, hungry or pass a lot more urine than usual. Tell your nurse or doctor if you have these symptoms or before you have asparaginase if you are diabetic.
• Change in mood or sleepiness - this may happen from the first day of treatment but should stop when you finish treatment

With this drug, a few people have a temporary drop in the number of blood cells made by the bone marrow, leading to the following side effects

• 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, sore throat, pain passing urine or feel cold and shivery. 
• Tiredness and breathlessness due to a drop in red blood cells (anaemia) - you may need a blood transfusion

These side effects can sometimes be life threatening, particularly infections.  You should contact your doctor if you have any of these effects. Your doctor will check your blood counts regularly to see how well your bone marrow is working

Other rare side effects include

• Inflammation of the pancreas (pancreatitis) causing pain in the centre of your abdomen and sickness - this usually gets better on its own after treatment has finished but you should not have asparaginase if you have had pancreatitis in the past and must tell your doctor if you have any of these symptoms
• Asparaginase can very rarely be toxic to your nervous system and cause drowsiness, loss of energy, confusion, agitation or hallucination - tell your doctor if you have any of these symptoms

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

Talk to your doctor, pharmacist or nurse about all your side effects so that they can help you manage them. Your chemotherapy nurse, clinic or ward nurse will give you a contact number. You can ring if you have any questions or problems. They can give you advice or reassure you. If in doubt, call them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies - some drugs can react together.

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 and yellow fever. 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 perfectly safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but not many people in the UK have oral vaccines now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. If you live abroad, you might need to make sure that you aren't in contact with anyone who has had oral polio or oral typhoid vaccination recently.