Care During Chemotherapy and Beyond



(peg AS par jase)

Trade names:  Oncaspar®
Other names:  PEG-L-asparaginase

Drug type: Pegaspargase is an anti-cancer ("antineoplastic" or "cytotoxic") chemotherapy drug.  This medication is classified as an "enzyme."  (For more detail, see "How this drug works" section below).

What This Drug Is Used For:

  • Pegaspargase is used to treat acute lymphocytic leukemia (ALL).
  • Non-Hodgkin's lymphoma.
  • Used in some patients who have had a hypersensitivity reaction to another form of asparaginase.

Note:  If a drug has been approved for one use, physicians may elect to use this same drug for other problems if they believe it may be helpful.

How This Drug Is Given:

  • Pegaspargase is given as an injection into a large muscle (intramuscular or IM).  Depending on your dose, the medication may need to be divided into two injections.
  • Pegaspargase may be given into the vein as an infusion (intravenous or IV). 
  • There is no pill form of pegaspargase.
  • The amount of pegaspargase that you will receive, and how it is given, depends on many factors, including your height and weight, your general health or other health problems, and the type of cancer or condition being treated.  Your doctor will determine your dose and schedule.

Side Effects:

Important things to remember about the side effects of pegaspargase:

  • Most people do not experience all of the side effects listed.
  • Side effects are often predictable in terms of their onset and duration.
  • Side effects are almost always reversible and will go away after treatment is complete.
  • There are many options to help minimize or prevent side effects.
  • There is no relationship between the presence or severity of side effects and the effectiveness of the medication.

The following side effects are common (occurring in greater than 30%) for patients taking pegaspargase:

  • Nausea and vomiting, generally mild
  • Poor appetite
  • Stomach pain
  • Weakness

These side effects are less common (occurring in about 10-29%) of patients receiving pegaspargase:

  • Allergic reaction, (sudden onset of wheezing, itching, rash, face swelling, agitation, low blood pressure).  You will be monitored closely for this reaction. 
  • Fatigue, lethargy, drowsiness, and excessive sleepiness. 
  • Diarrhea.
  • Mouth sores.
  • Increases in blood tests measuring pancreatic enzymes (amylase and lipase).
  • Increases in blood tests measuring liver function.  These return to normal once treatment is discontinued.
  • Blood clotting disorders, increases risk of both bleeding and clotting.

A serious but rare side effect of pegaspargase is pancreatitis (inflammation of the pancreas).

  • Symptoms of acute pancreatitis include: (pain in the upper abdomen that worsens with eating, swollen and tender abdomen, nausea, vomiting, fever, and rapid pulse).

Not all side effects are listed above. Some that are rare (occurring in less than 10% of patients) are not listed here.  However, you should always inform your health care provider if you experience any unusual symptoms.

When to contact your doctor or health care provider:

Contact your health care provider immediately, day or night, if you should experience any of the following symptoms:

  • Fever of 100.4° F (38° C) or higher, chills (possible signs of infection)

The following symptoms require medical attention, but are not an emergency.  Contact your health care provider within 24 hours of noticing any of the following:

  • Nausea (interferes with ability to eat and unrelieved with prescribed medication)
  • Vomiting (vomiting more than 4-5 times in a 24 hour period)
  • Persistent upper abdominal pain or pain that worsens with eating
  • Abdominal swelling
  • Diarrhea (4-6 episodes in a 24-hour period)
  • Unusual bleeding or bruising
  • Swelling, redness and/or pain in one leg or arm and not the other. Extreme fatigue (unable to carry on self-care activities).
  • Yellowing of the skin or eyes
  • Unusual thirst, need to urinate frequently
  • Swelling of feet and ankles or sudden weight gain
  • Confusion, excessive sleepiness, hallucinations (seeing, hearing or feeling things that are not there), agitation, or disorientation (not able to recognize familiar surroundings).

Always inform your health care provider if you experience any unusual symptoms.


  • Before starting pegaspargase treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.).   Do not take aspirin, products containing aspirin unless your doctor specifically permits this.
  • Do not receive any kind of immunization or vaccination without your doctor's approval while taking asparaginase.
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment.  Pregnancy category C (use in pregnancy only when benefit to the mother outweighs risk to the fetus). 
  • For both men and women: Do not conceive a child (get pregnant) while taking pegaspargase. Barrier methods of contraception, such as condoms, are recommended. Discuss with your doctor when you may safely become pregnant or conceive a child after therapy.
  • Do not breast feed while taking this medication.
  • Those who have a history of pancreatitis (inflammation of the pancreas) should not be treated with asparaginase.

Monitoring and Testing:

You will be checked regularly by your doctor while you are taking asparaginase, to monitor side effects and check your response to therapy.  Periodic blood work to monitor your complete blood count (CBC), blood clotting factors, pancreatic enzymes, blood sugar as well as the function of other organs (such as your kidneys and liver) will also be ordered by your doctor.   

Self-Care Tips:

  • Drink at least two to three quarts of fluid every 24 hours, unless you are instructed otherwise.
  • For flu-like symptoms, keep warm with blankets and drink plenty of liquids.  There are medications that can help reduce the discomfort caused by chills.
  • You may be at risk of infection so try to avoid crowds or people with colds, and report fever or any other signs of infection immediately to your health care provider.
  • Wash your hands often.
  • To help treat/prevent mouth sores, use a soft toothbrush, and rinse three times a day with 1/2 to 1 teaspoon of baking soda and/or 1/2 to 1 teaspoon of salt mixed with 8 ounces of water.
  • Use an electric razor and a soft toothbrush to minimize bleeding.
  • Avoid contact sports or activities that could cause injury.
  • To reduce nausea, take anti-nausea medications as prescribed by your doctor, and eat small, frequent meals. 
  • Avoid driving and tasks that require being alert until your response to this drug is well understood.
  • Avoid sun exposure.  Wear SPF 15 (or higher) sunblock and protective clothing.
  • In general, drinking alcoholic beverages should be kept to a minimum or avoided completely.  You should discuss this with your doctor.
  • Get plenty of rest. 
  • Maintain good nutrition.
  • If you experience symptoms or side effects, be sure to discuss them with your health care team.  They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

How This Drug Works:

All cells need a chemical called asparagine to stay alive. Normal cells can make this chemical for themselves, while cancer cells cannot.  The enzyme asparaginase breaks down asparagine in the body. Since the cancer cells cannot make more asparagine, they die.  Pegaspargase is a modified version of the enzyme asparaginase.

When pegaspargase breaks down asparagine it is broken down into 2 chemicals, aspartic acid and ammonia.  The neurologic side effects seen with asparaginase (such as, confusion, excessive sleepiness, agitation, disorientation, or coma) are related to increased levels of these chemicals circulating in the body.

Note:  We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice. is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit