Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page:

Asparaginase Erwinia Chrysanthemi (recombinant)-rywn Injection

pronounced as (as par' a jin ase) (er win' ee a) (kri san' the mee)

Why is this medication prescribed?

Asparaginase erwinia chrysanthemi (recombinant)-rywn injection is used with other chemotherapy medications to treat acute lymphocytic leukemia (ALL; a type of cancer of the white blood cells) and to treat a type of non-Hodgkins lymphoma (NHL: cancer that begins in a type of white blood cell that normally fights infection) in adults and children 1 month of age and older. It is used in people who have had some types of allergic reactions to medications similar to asparaginase erwinia chrysanthemi (recombinant)-rywn such as asparaginase (Elspar). Asparaginase erwinia chrysanthemi (recombinant)-rywn is an enzyme that interferes with natural substances necessary for cancer cell growth. It works by killing or stopping the growth of cancer cells.

How should this medicine be used?

Asparaginase erwinia chrysanthemi (recombinant)-rywn comes as a solution (liquid) to be given intramuscularly (injected into a muscle) by a doctor or nurse in a medical facility. It is usually given every 48 hours. It may also be given three times a week, every Monday morning, every Wednesday, morning, and every Friday afternoon. The length of treatment depends on how you respond to the medication.

Your doctor may need to delay your treatment or stop your treatment if you experience certain side effects. It is important for you to tell your doctor how you are feeling during your treatment with asparaginase erwinia chrysanthemi (recombinant)-rywn injection.

Asparaginase erwinia chrysanthemi (recombinant)-rywn injection may cause serious allergic reactions. You will be given medications 30 to 60 minutes before your injection to help prevent reactions to asparaginase erwinia chrysanthemi (recombinant)-rywn. A doctor or nurse will watch you closely while you are receiving asparaginase erwinia chrysanthemi (recombinant)-rywn injection. Tell your doctor or nurse immediately if you experience any of the following symptoms: rash; hives; swelling of face, lips, eyes, arms, or legs; or shortness of breath or difficulty breathing.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before receiving asparaginase erwinia chrysanthemi (recombinant)-rywn,

  • tell your doctor and pharmacist if you are allergic to asparaginase erwinia chrysanthemi (recombinant)-rywn, any other medications, or any of the ingredients in asparaginase erwinia chrysanthemi (recombinant)-rywn. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had pancreatitis (swelling of the pancreas), blood clots, or severe bleeding, especially if these happened during treatment with asparaginase (Elspar). Your doctor probably will not want you to receive asparaginase erwinia chrysanthemi (recombinant)-rywn.
  • tell your doctor if you have or have ever had diabetes or any other medical conditions.
  • tell your doctor if you are pregnant or plan to become pregnant. You will need to take a pregnancy test before you start treatment and use a non-hormonal birth control (device that blocks sperm from entering the uterus such as a condom or a diaphragm) during your treatment and for 3 months after your final dose. Talk to your doctor about birth control methods that you can use during your treatment. If you become pregnant while receiving asparaginase erwinia chrysanthemi (recombinant)-rywn, call your doctor immediately. Asparaginase erwinia chrysanthemi (recombinant)-rywn may harm the fetus.
  • tell your doctor if you are breastfeeding. You should not breastfeed while you are receiving asparaginase erwinia chrysanthemi (recombinant)-rywn and for 1 week after the final dose.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What side effects can this medication cause?

Asparaginase erwinia chrysanthemi (recombinant)-rywn may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea
  • diarrhea
  • constipation
  • muscle or bone pain
  • headache
  • tiredness
  • loss of appetite
  • difficulty falling asleep or staying asleep
  • sores on the lips, mouth, or throat
  • numbness or tingling in your hands, feet, arms, or legs

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • swelling of face, lips, eyes, arms, or legs
  • hives
  • itching
  • rash or redness
  • shortness of breath or difficulty breathing
  • yellowing of skin or eyes, pain in upper right part of stomach, dark-colored urine, or loss of appetite
  • unusual bleeding or bruising
  • nose bleeding
  • blood in urine
  • blurred vision, headache, arm or leg swelling, shortness of breath, and chest pain
  • fever, chills, cough, or other signs of infection
  • rapid or increased heart rate
  • ongoing pain that begins in the stomach area, but may spread to the back; fever; weight loss; or nausea and vomiting

Asparaginase erwinia chrysanthemi (recombinant)-rywn may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( or by phone (1-800-332-1088).

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to asparaginase erwinia chrysanthemi (recombinant)-rywn.

Ask your pharmacist any questions you have about asparaginase erwinia chrysanthemi (recombinant)-rywn.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Rylaze®
Last Revised - 01/15/2023