Asparaginase (Elspar®)

Last Modified: August 11, 2011

Pronounced: as-PAR-a-jin-ase
Classification: Enzyme, Antineoplastic agent

About Asparaginase

Asparaginase is an enzyme (a protein that makes chemical reactions go faster) that speeds up the reaction that turns asparagine into aspartic acid and ammonia. Cancerous white blood cells depend on asparagine to survive, so if all of it is used up through the catalyzed reaction, the cancerous cells die. Normal white blood cells can produce their own asparagine, and are therefore less affected by the drug.

How to Take Asparaginase

Asparaginase is given by intravenous (into a vein) infusion or intramuscular (into a muscle) infusion, over at least 30 minutes. It can be given alone or with other drugs. Asparaginase can be given in various dosing schedules, depending on the regimen being used.

Possible Side Effects of Asparaginase

There are a number of things you can do to manage the side effects of Asparaginase. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:

Allergic Reactions

Rash, itching, redness, hives and/or difficulty breathing during the treatment or shortly after the treatment. To see if you will have an allergic reaction, you will receive a small dose as a skin test before receiving your first dose of asparaginase and whenever more than one week passes between treatments. It may be necessary for the nurse to observe you for a period of time after you receive the asparaginase and/or give you medications to counteract the effects. Notify your doctor or nurse if you have experience any of these symptoms.

Fever, Loss of Energy, or Body Aches

If you experience fever or chills, let your doctor or nurse know. Before taking any medications contact your doctor or nurse.

Liver Changes

Your doctor may order some blood tests to check your liver function. Call your doctor or nurse immediately if you have abdominal pain, your urine becomes dark in color, or if your skin or the white of your eyes become jaundiced (yellow in color).

Pancreas Changes

Your doctor may order some blood tests to check how your pancreas is functioning. Call your doctor or nurse if you have abdominal pain, nausea, vomiting, frequent urination or feel thirsty all the time.

Low White Blood Cell Count (Leukopenia or Neutropenia)

White blood cells (WBC) are important for fighting infection. While receiving treatment, your WBC count can drop, putting you at a higher risk of getting an infection. You should let your doctor or nurse know right away if you have a fever (temperature greater than 100.4 F), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.

Tips to preventing infection:

  • Washing hands, both yours and your visitors, is the best way to prevent the spread of infection.
  • Avoid large crowds and people who are sick (i.e.: those who have a cold, fever or cough or live with someone with these symptoms).
  • When working in your yard, wear protective clothing including long pants and gloves.
  • Do not handle pet waste.
  • Keep all cuts or scratches clean.
  • Shower or bath daily and perform frequent mouth care.
  • Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
  • Ask your doctor or nurse before scheduling dental appointments or procedures.
  • Ask your doctor or nurse before you, or someone you live with, has any vaccinations.

For more suggestions, read the Neutropenia Tip Sheet.

Low Red Blood Cell Count (Anemia)

Your red blood cells are responsible for carrying oxygen to the tissues in your body. When the red cell count is low, you may feel tired or weak. You should let your doctor or nurse know if you experience any shortness of breath, difficulty breathing or pain in your chest. If the count gets too low, you may receive a blood transfusion. Read the anemia tip sheet for more information.

Low Platelet Count (Thrombocytopenia)

Platelets help your blood clot, so when the count is low you are at a higher risk of bleeding. Let your doctor or nurse know if you have any excess bruising or bleeding, including nose bleeds, bleeding gums or blood in your urine or stool. If your platelet count becomes too low, you may receive a transfusion of platelets.

  • Do not use a razor to shave (an electric razor is fine).
  • Avoid contact sports and activities that can result in injury or bleeding.
  • Do not take aspirin (salicylic acid), non-steroidal, anti-inflammatory medications (NSAIDs) such as Motrin®, Aleve®, Advil®, etc. as these can all increase the risk of bleeding. Unless your healthcare team tells you otherwise, you may take acetaminophen (Tylenol).
  • Do not floss or use toothpicks and use a soft-bristle toothbrush to brush your teeth.

Read the thrombocytopenia tip sheet for more information.

Nausea and/or Vomiting

Take anti-nausea medications as prescribed. If you continue to have nausea or vomiting, notify your doctor or nurse so they can help you manage this side effect. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms. Read the Nausea & Vomiting Tip Sheet for more suggestions.

Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.

Nervous System Changes

You may feel tired, depressed, confused or upset. Call your doctor or nurse if you feel confused, drowsy or are hearing, seeing, or feeling things that are not there.


See OncoLink's section on fatigue for helpful tips on dealing with this side effect.

Decrease in Appetite

Visit OncoLink's section on Nutrition for tips on dealing with this side effect. Ask your nurse about nutritional counseling services.

  • Try to eat five or six small meals or snacks throughout the day, instead of 3 larger meals.
  • If you are not eating enough, nutritional supplements may help.
  • You may experience a metallic taste or dislike foods or beverages that you liked before receiving chemotherapy. These symptoms can last up to several months.
  • Avoid any food that you think smells or tastes bad. If red meat is a problem, eat chicken, turkey, eggs, dairy products and fish without a strong smell.
  • Flavor meat or fish by marinating it in sweet juices, sweet and sour sauce or dressings. Use seasonings like basil, oregano or rosemary. Bacon, ham and onion can also add flavor to vegetables.

Sexual and Reproductive Changes

This drug can affect your reproductive system, resulting in the menstrual cycle or sperm production becoming irregular or stopping permanently. Women may experience menopausal effects including hot flashes and vaginal dryness - read more about coping with vaginal dryness. In addition, the desire for sex may decrease during treatment.

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment, even if your menstrual cycle stops or you believe your sperm is affected. You may want to consider sperm banking or egg harvesting if you may wish to have a child in the future. Discuss these options with your oncology team. See OncoLink's section on sexuality for helpful tips for dealing with these side effects.