Cytarabine

Cytarabine is a cancer medicine that interferes with the growth and spread of cancer cells in your body. Cytarabine is a cytosine analogue and antineoplastic agent used largely in the therapy of leukemia (cancer of the white blood cells), including acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), and chronic myelogenous leukemia (CML). Current indications include initial, consolidation and maintenance therapy of acute myelogenous and other acute leukemias. Cytarabine is also used alone or with other chemotherapy drugs to treat meningeal leukemia (cancer in the membrane that covers and protects the spinal cord and brain). Cytarabine has potent activity in acute leukemia and was approved for use in the United States in 1969 and is still widely used ¹.

Cytarabine is also sometimes used to treat certain types of non-Hodgkin’s lymphoma (a type of cancer that begins in a type of white blood cells that normally fights infection). Talk to your doctor about the risks of using this medication for your condition.

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

Cytarabine is in a class of medications called antimetabolites. It works by slowing or stopping the growth of cancer cells in your body. Cytarabine is an nucleoside analogue (cytosine arabinoside: ara-C) which is converted intracellularly to a triphosphate, which competes with cytosine triphosphate for incorporation into RNA and DNA and acts as an inhibitor of RNA and DNA polymerase, thus blocking DNA synthesis and cell division.

Cytarabine comes as a powder to mixed with liquid to be injected intravenously (into a vein), subcutaneously (under the skin), or intrathecally (into the fluid-filled space of the spinal canal) by a doctor or nurse in a medical facility. Your doctor will tell you how often you will receive cytarabine. The schedule depends on the condition you have and on how your body responds to the medication.

Cytarabine is available in vials of 100, 500, 1000 and 2000 mg (20 mg/mL) for intravenous or intrathecal infusion generically and under the brand name Cytosar-U. Liposomal sustained release formulations are also available for intrathecal administration (DepoCyt). The dose regimen of cytarabine varies by body surface area and indication. A typical induction dose is 100 mg per meter squared by continuous intravenous infusion on days 1 to 7. Common side effects include bone marrow suppression, nausea, vomiting, oral or anal ulcers, abdominal pain, myalgias, bone pain, chest pain, conjunctivitis headache, fatigue, fever, rash and pruritus.

Cytarabine special precautions

Before receiving cytarabine injection:

• tell your doctor and pharmacist if you are allergic to cytarabine or any of the ingredients in cytarabine injection. 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. Be sure to mention any of the following: digoxin (Lanoxin), flucytosine (Ancobon), or gentamicin. Other medications may also interact with cytarabine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• tell your doctor if you have or have ever had kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. You should not become pregnant while you are receiving cytarabine injection. If you become pregnant while receiving cytarabine, call your doctor. Cytarabine may harm the fetus.

What should I avoid while receiving cytarabine?

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

cytarabine can pass into body fluids (urine, feces, vomit). For at least 48 hours after you receive a dose, avoid allowing your body fluids to come into contact with your hands or other surfaces. Caregivers should wear rubber gloves while cleaning up a patient’s body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Do not receive a “live” vaccine while using cytarabine. The vaccine may not work as well during this time, and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

Cytarabine dose

Cytarabine is given as an injection through a needle placed into a vein, under the skin, or into the space around the spinal cord. A healthcare provider will give you this injection.

Cytarabine is usually given for only a few days at a time. Follow your doctor’s dosing instructions very carefully.

After receiving an injection, you will be watched closely to make sure you do not have serious side effects.

Cytarabine can lower blood cells that help your body fight infections and help your blood to clot. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood may need to be tested often.

Administration advice:

• Only the preservative free formulation of this drug should be administered intrathecally.
• Therapy should be started cautiously in patients with preexisting drug-induced bone marrow suppression.
• Patients receiving this drug should be under close medical supervision.

Monitoring:

• During induction therapy, patients should have leucocyte and platelet counts performed daily.
• Bone marrow examinations should be performed frequently after blasts have disappeared from the peripheral blood.

Adult dose for acute nonlymphocytic leukemia

Use: Acute lymphocytic leukemia

Induction as part of combination chemotherapy: 100 mg/m²/day by continuous IV infusion (Days 1 through 7) or 100 mg/m² IV every 12 hours (Days 1 through 7)

Adult dose for acute lymphocytic leukemia

Use: Acute lymphocytic leukemia

The literature and/or local protocol should be consulted.

Adult dose for meningeal leukemia

Use: Meningeal leukemia

The dose ranges from 5 mg/m² to 75 mg/m² intrathecally once a day for 4 days to once every 4 days (30 mg/m² every 4 days until cerebrospinal fluid findings are normal, followed by one additional treatment is the most frequently used dose)

Comments:

• Only the preservative free formulation of this drug should be administered intrathecally.

Pediatric dose for acute nonlymphocytic leukemia

Use: Acute lymphocytic leukemia

Induction as part of combination chemotherapy: 100 mg/m²/day by continuous IV infusion (Days 1 through 7) or 100 mg/m2 IV every 12 hours (Days 1 through 7)

Comments:

• Children appear to tolerate higher doses of this drug than adults, and where the range of doses is given, children should receive the higher dose.

Pediatric dose for acute lymphocytic leukemia

Use: Acute lymphocytic leukemia

The literature and/or local protocol should be consulted.

Pediatric dose for meningeal leukemia

Use: Meningeal leukemia

The dose ranges from 5 mg/m² to 75 mg/m² intrathecally once a day for 4 days to once every 4 days (30 mg/m² every 4 days until cerebrospinal fluid findings are normal, followed by one additional treatment is the most frequently used dose)

Comments:

• Children appear to tolerate higher doses of this drug than adults, and where the range of doses is given, children should receive the higher dose.
• Only the preservative free formulation of this drug should be administered intrathecally.

Renal dose adjustments

• Data not available

Liver dose adjustments

• Data not available

Dialysis

• Data not available

Cytarabine side effects

Cytarabine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• nausea
• vomiting
• diarrhea
• stomach pain
• loss of appetite
• sores in the mouth and throat
• hair loss
• muscle or joint pain
• tiredness
• sore or red eyes

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment:

• ongoing pain that begins in the stomach area but may spread to the back
• redness, pain, swelling, or burning at the site where the injection was given
• pale skin
• fainting
• dizziness
• fast or irregular heartbeat
• rash
• hives
• itching
• difficulty breathing or swallowing
• chest pain
• yellowing of the skin or eyes
• dark-colored urine or decreased urination
• shortness of breath
• sudden change or loss of vision
• seizures
• confusion
• numbness, burning, or tingling in the hands, arms, feet, or legs

Cytarabine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

US Boxed Warnings

• Only physicians experienced in cancer chemotherapy should use this drug.
• For induction therapy patients should be treated in a facility with laboratory and supportive resources to monitor drug tolerance and protect and maintain a patient compromised by drug toxicity.
• The main toxic effect of this drug is bone marrow suppression with leukopenia, thrombocytopenia, and anemia. Less serious toxicity includes nausea, vomiting, diarrhea, abdominal pain, oral ulceration, and hepatic dysfunction.
• The physician should evaluate the benefit to the patient against known toxic effects of this drug in considering the advisability of therapy.

1. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-. Cytarabine. [Updated 2017 Nov 3]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK548291