Drug Formulary information is intended for use by healthcare professionals. It is not intended to be medical advice. Some of the information, including information about funding for cancer drugs, does not apply to all patients. Cancer treatment plans are unique to each patient. If you are a patient, please speak with your healthcare team to understand how this information applies to you.
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drug-infosheet
pegaspargase
Cancer Type
Hematologic,
Leukemia - Acute Lymphoblastic (ALL),
Lymphoma - T-cell
Other Names
Oncaspar®
Appearance
Clear solution for injection; may be mixed into larger bags of fluids
pegaspargase
Pronunciation:
peg-AS-par-gase
Other Name(s):
Oncaspar®
Appearance:
Clear solution for injection; may be mixed into larger bags of fluids
This handout gives general information about this cancer medication.
You will learn:
who to contact for help
what the medication is
how it is given
what to expect while on medication
This handout was created by Ontario Health (Cancer Care Ontario) together with patients and their caregivers who have also gone through cancer treatment. It is meant to help support you through your cancer treatment and answer some of your questions.
This information does not replace the advice of your health care team. Always talk to your health care team about your treatment.
Who do I contact if I have questions or need help?
My cancer health care provider is: _____________________________________________
During the day I should contact: _______________________________________________
Evenings, weekends and holidays: _____________________________________________
This page gives general information about this cancer medication.
You will learn:
who to contact for help
what the medication is
how it is given
what to expect while on this medication
This information was created by Ontario Health (Cancer Care Ontario) together with patients and their caregivers who have also gone through cancer treatment. It is meant to help support you through your cancer treatment and answer some of your questions.
This information does not replace the advice of your health care team. Always talk to your health care team about your treatment.
What is this treatment for?
Used in combination with other cancer drugs for treating certain types of blood cancers (such as Acute Lymphoblastic Leukemia) or lymphomas.
What should I do before I start this treatment?
Tell your health care team if you have or had significant medical condition(s), especially if you have / had
blood clots or bleeding problems,
diabetes,
problems with your kidney, liver or pancreas, or
any allergies (or if you cannot tolerate asparaginase)
Remember To:
Tell your health care team about all of the other medications you are taking.
Keep taking other medications that have been prescribed for you, unless you have been told not to by your health care team.
You will have a blood test to check for hepatitis B before starting treatment. See the Hepatitis B and Cancer Medications pamphlet for more information.
How is this treatment given?
This drug is given by injection into a muscle or through an IV (injected into a vein). Talk to your health care team about your treatment schedule.
If you missed your treatment appointment, talk to your health care team to find out what to do.
Other medications you may be given with this treatment
To Prevent Allergic Reaction
You may be given medications before your treatment to help prevent allergic reactions before they start.
There are different types of medications to stop allergic reactions. They are called:
- antihistamines (such as diphenhydramine or Benadryl®)
- analgesics/antipyretics (such as acetaminophen or Tylenol®)
- H2 blockers (such as ranitidine or famotidine)
- corticosteroids (such as prednisone)
To Prevent Tumor Lysis Syndrome (TLS)
TLS can happen when a large number of cancer cells die quickly and your body cannot get rid of them fast enough. TLS can make you very sick. Ask your health care team if you are at risk for TLS.
If you are at risk for TLS, you may be given medications before your pegaspargase treatment to help prevent it.
- These are called anti-uricemics (such as allopurinol), or others.
| DO this while on treatment | DO NOT do this while on treatment | |
|
|
|
DO this while on treatment
DO check with your health care team before getting any vaccinations, surgery, dental work or other medical procedures.
DO consider asking someone to drive you to and from the hospital on your treatment days. You may feel drowsy or dizzy after your treatment.
DO NOT do this while on treatment
DO NOT take any other medications, such as vitamins, over-the-counter (non-prescription) drugs or substances, or natural health products without checking with your health care team.
DO NOT start any complementary or alternative therapies, such as acupuncture or homeopathic products, without checking with your health care team.
DO NOT use tobacco products (such as smoking cigarettes or vaping) or drink alcohol while on treatment without talking to your health care team first. Smoking and drinking can make side effects worse and make your treatment not work as well.
Will this treatment interact with other medications or natural health products?
Yes, this medication can interact with other medications, vitamins, foods, traditional medicines and natural health products. Interactions can make this medication not work as well or cause severe side effects.
Tell your health care team about all of your:
- prescription and over-the-counter (non-prescription) medications
- other drugs and substances, such as cannabis/marijuana (medical or recreational)
- natural health products such as vitamins, herbal teas, homeopathic medicines, and other supplements, or traditional medicines
Check with your health care team before starting or stopping any of them.
Talk to your health care team BEFORE taking or using these :
- Anti-inflammatory medications such as ibuprofen (Advil® or Motrin®), naproxen (Aleve®) or Aspirin®.
- Over-the-counter products such as dimenhydrinate (Gravol®)
- Natural health products such as St. John’s Wort
- Traditional medicines
- Supplements such as vitamin C
- Grapefruit juice
- Alcoholic drinks
- Tobacco
- All other drugs or substances, such as marijuana or cannabis (medical or recreational)
What to do if you feel unwell, have pain, a headache or a fever
Always check your temperature to see if you have a fever before taking any medications for fever or pain (such as acetaminophen (Tylenol®) or ibuprofen (Advil®)).
Fever can be a sign of infection that may need treatment right away.
If you take these medications before you check for fever, they may lower your temperature and you may not know you have an infection.
How to check for fever:
Keep a digital (electronic) thermometer at home and take your temperature if you feel hot or unwell (for example, chills, headache, mild pain).
You have a fever if your temperature taken in your mouth (oral temperature) is:
38.3°C (100.9°F) or higher at any time
OR
38.0°C (100.4°F) or higher for at least one hour.
If you do have a fever:
Try to contact your health care team. If you are not able to talk to them for advice, you MUST get emergency medical help right away.
Ask your health care team for the Fever pamphlet for more information.
If you do not have a fever but have mild symptoms such as headache or mild pain:
- Ask your health care team about the right medication for you. Acetaminophen (Tylenol®) is a safe choice for most people.
Talk to your health care team before you start taking ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or ASA (Aspirin®), as they may increase your chance of bleeding or interact with your cancer treatment.
Talk to your health care team if you already take low dose aspirin for a medical condition (such as a heart problem). It may still be safe to take.
How will this treatment affect sex, pregnancy and breastfeeding?
Talk to your health care team about:
How this medication may affect your sexual health.
How this medication may affect your ability to have a baby, if this applies to you.
This medication may harm an unborn baby. Tell your health care team if you or your partner are pregnant, become pregnant during treatment, or are breastfeeding.
If there is any chance of pregnancy happening, you and your partner together must use 2 effective forms of birth control at the same time until at least 6 months after your last treatment dose. Talk to your health care team about which birth control options are best for you.
This medication may make hormonal birth control, such as birth control pills, less effective (not work as well). If you choose to use a hormonal birth control, make sure you also use a barrier or non-hormonal birth control method (such as condoms). Talk to your health care team about the best birth control options for you.
Do not breastfeed while on this medication and for 1 month after your last dose.
What are the side effects of this treatment?
The following table lists side effects that you may have when getting pegaspargase. The table is set up to list the most common side effects first and the least common last. It is unlikely that you will have all of the side effects listed and you may have some that are not listed.
Read over the side effect table so that you know what to look for and when to get help. Refer to this table if you experience any side effects while on pegaspargase.
| Side Effects (in 10 or more out of 100 people) | |
| Side effects and what to do | When to contact health care team |
Liver problems Your health care team may check your liver function with a blood test. Liver changes do not usually cause any symptoms.
If you have any symptoms of liver problems, get emergency medical help right away. |
Get emergency medical help right away. |
Pains or cramps in the belly What to look for?
|
Talk to your health care team if it does not improve or if it is severe. |
Diarrhea What to look for?
What to do? If you have diarrhea:
Ask your health care team for the Diarrhea pamphlet for more information. |
Talk to your health care team if no improvement after 24 hours of taking diarrhea medication or if severe (more than 7 times in one day). |
High blood sugar What to look for?
|
Contact your health care team as soon as possible (office hours). |
Higher than normal levels of pancreas enzymes in your blood (lipase, amylase) What to look for?
If you have any symptoms, get emergency medical help right away. |
Talk to your health care team if you have any symptoms. If you are unable to talk to the team for advice, you must get emergency medical help right away. |
Allergic reaction What to look for?
|
Get emergency medical help right away for severe symptoms. |
Other rare, but serious side effects are possible with this treatment.
If you have any of the following, talk to your cancer health care team or get emergency medical help right away:
have signs of infection (for example, feeling unwell, new cough) or fever. You have a fever if your temperature taken in your mouth (oral temperature) is 38.3°C (100.9°F) or higher at any time OR 38.0°C (100.4°F) or higher for at least one hour
black coloured stools (poo) or blood in your stools (poo),heavy vaginal bleeding, red or pink coloured urine (pee) or bleeding that will not stop
feeling confused
suddenly losing your vision, having trouble speaking or using your arms or legs
chest pain
trouble breathing, coughing up blood
pain, swelling and hardening of the vein in an arm or leg
severe headache, passing out (fainting)
seizures
hallucinations (seeing or hearing things that aren’t there)
severe numbness, tingling, or burning sensation of fingers, toes or other parts of the body, having pain or trouble moving
sudden, severe pain in your belly
new lower back pain with swelling, peeing less than usual and unusual weight gain
- sudden weight gain, buildup of fluids in the belly that make it look swollen or make the right side (liver) feel larger
muscle twitching, severe weakness or cramping
irregular or fast heartbeat
For more information on how to manage your symptoms ask your health care provider, or visit: https://www.cancercareontario.ca/symptoms.
Notes
June 2026 Updated/revised information sheet
The information set out in the medication information sheets, regimen information sheets, and symptom management information (for patients) contained in the Drug Formulary (the "Formulary") is intended to be used by health professionals and patients for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or side effects of a certain drug, nor should it be used to indicate that use of a particular drug is safe, appropriate or effective for a given condition.
A patient should always consult a healthcare provider if he/she has any questions regarding the information set out in the Formulary. The information in the Formulary is not intended to act as or replace medical advice and should not be relied upon in any such regard. All uses of the Formulary are subject to clinical judgment and actual prescribing patterns may not follow the information provided in the Formulary.
Last Updated: July 21, 2026
