What is tumour lysis syndrome?

Tumour lysis syndrome (TLS) can be caused by some chemotherapy drugs. Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. As the cancer cells break down, they release a chemical called uric acid. The kidneys remove uric acid from the body.

TLS can happen when lots of cancer cells are destroyed very quickly. The kidneys cannot cope with the increased amount of uric acid. This causes imbalances in some chemicals (phosphate, potassium and calcium) in the blood. These imbalances can cause more serious problems, which affect the kidneys and the heart.

TLS is more common in cancers that grow quickly and respond quickly to chemotherapy, such as acute leukaemias and high-grade lymphomas. People with other types of cancer are rarely affected by TLS.

How rasburicase works

Rasburicase changes uric acid so the kidneys can easily process it and remove it from the body. This prevents a build-up of uric acid.

How rasburicase is given

Rasburicase is given before, or with, your first chemotherapy treatment.

Your nurse can give you rasburicase through:

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

Your nurse gives you rasburicase as a drip into a vein (infusion). They give you the infusion over 30 minutes. You may have one dose or a daily dose for up to 7 days. Your doctors decide how many days of treatment you need. They do this by taking regular blood samples to check the level of uric acid in your blood.

They also give you large amounts of fluids through a line into your bloodstream to help flush through your kidneys. This is called intravenous hydration. This means you pass more urine (pee) than usual.

About side effects

Each person’s reaction to any medication is different. Most people have very few side effects, while others may experience more. The side effects described here will not affect everyone who is having rasburicase.

You may also have side effects from the cancer drugs you are given. If you notice any side effects that are not listed here, discuss them with your nurse or doctor.

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.

Before you have rasburicase

It is important to tell your doctor if you:

  • have ever had haemolytic anaemia (an illness caused by red blood cells being abnormally broken down)
  • have the metabolic disorder Glucose-6-phosphate dehydrogenase (G6PD) deficiency, which can cause haemolytic anaemia.

Rasburicase is not suitable for people who have G6PD deficiency or similar disorders that can cause haemolytic anaemia.

Possible side effects of rasburicase

High temperature

Your nurse will monitor your temperature during treatment. Signs of a high temperature can include feeling hot and sweaty or cold and shivery. It is important to tell your nurse or doctor if you have a high temperature.

Allergic reaction

Rarely, rasburicase may cause an allergic reaction while it is being given. Your nurse will check you for this. If you have a reaction, they will treat it quickly. Signs of an allergic reaction can include:

  • a rash
  • feeling itchy
  • feeling short of breath
  • chest pain.

Tell your nurse straight away if you have any of these symptoms.


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 sick (nausea)

You may feel sick or be sick (vomit) during treatment with rasburicase. Your doctor can prescribe anti-sickness drugs (anti-emetics) to help.

Take the drugs exactly as your nurse or pharmacist tells you to. If you are sick after taking rasburicase, contact the hospital for advice.


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

Blood changes

Rarely, rasburicase can increase the breakdown of red blood cells. You will have regular blood tests during your treatment to check for this.

Other information

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.

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.

Pregnancy and breastfeeding

If you are pregnant, think you may be pregnant, or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Women are also advised not to breastfeed when taking this treatment. This is because the medicine may be passed to the baby through the breast milk. 

How we can help

How to print a PDF from this website
Instructions on how you can make a PDF version of this page using the print function on your browser.
Macmillan Grants

If you have cancer, you may be able to get a Macmillan Grant to help with the extra costs of cancer. Find out who can apply and how to access our grants.

0808 808 00 00
7 days a week, 8am - 8pm
Email us
Get in touch via this form
Chat online
7 days a week, 8am - 8pm
Online Community
An anonymous network of people affected by cancer which is free to join. Share experiences, ask questions and talk to people who understand.
Help in your area
What's going on near you? Find out about support groups, where to get information and how to get involved with Macmillan where you live.