Common brand names

• Cytosar-U

How it is administered

Cytarabine is administered as an injection. It can be given in several ways:

• Intravenous (IV) infusion or injection: Directly into a vein, either as a slow infusion over several hours or as a rapid injection.
• Subcutaneous injection: Injected under the skin.
• Intrathecal injection: Injected into the fluid around the spinal cord (for certain types of leukemia affecting the central nervous system).

The exact method and schedule depend on the treatment plan your doctor prescribes. Cytarabine is not effective if taken by mouth.

How it works

Cytarabine is a type of chemotherapy medication known as an antimetabolite. It works by interfering with the DNA synthesis of rapidly dividing cells, such as cancer cells. Specifically, cytarabine is incorporated into DNA during the S-phase of the cell cycle, which is when cells are actively replicating their DNA in preparation for cell division.

By mimicking a building block of DNA, cytarabine blocks the action of an enzyme called DNA polymerase, which is essential for making new DNA. This disruption prevents cancer cells from multiplying and leads to their death. Because it targets cells that are dividing quickly, cytarabine also affects some healthy cells that grow rapidly, such as those in the bone marrow, digestive tract, and hair follicles, which can lead to side effects.

Who should take it

Cytarabine is used in combination with other approved anti-cancer drugs for the treatment of certain blood cancers. It is indicated for:

• Remission induction in acute non-lymphocytic leukemia (also known as acute myeloid leukemia, AML) in adults and children.
• Treatment of acute lymphocytic leukemia (ALL).
• Treatment of the blast phase of chronic myelocytic leukemia (CML).
• Intrathecal use (injection into the spinal fluid) for the prevention and treatment of meningeal leukemia (leukemia involving the central nervous system).

Your doctor will determine if cytarabine is appropriate for you based on your specific diagnosis and health status.

Who should not take it

Cytarabine should not be used in patients who are hypersensitive (allergic) to cytarabine or any of its components.

Cytarabine is a potent bone marrow suppressant, so it should be used cautiously in patients with pre-existing bone marrow suppression. It should also be used with caution in patients with impaired liver or kidney function, as these conditions may increase the risk of toxicity. Cytarabine can cause harm to an unborn baby, so it should not be used during pregnancy unless clearly needed, and women of childbearing potential should avoid becoming pregnant during treatment.

If you have had a severe allergic reaction to cytarabine in the past, or if you are pregnant or breastfeeding, discuss alternative treatments with your doctor.

Commonly used with

Cytarabine is most often used in combination with other chemotherapy drugs to increase its effectiveness. For example, it is commonly combined with:

• Daunorubicin or other anthracyclines (as in the '7+3' regimen for AML)
• Cyclophosphamide
• Vincristine
• Prednisone
• Methotrexate (especially for central nervous system involvement)

Your specific combination will depend on your diagnosis and treatment plan.

Commonly tested with

Cytarabine has been tested in clinical trials in combination with other chemotherapy agents, especially daunorubicin (as in the '7+3' regimen for AML) and other drugs such as cyclophosphamide, vincristine, prednisone, and methotrexate. It has also been studied in various regimens for both induction and consolidation therapy in acute leukemias and for central nervous system prophylaxis or treatment.

If you are participating in a clinical trial, your doctor will explain which medications are being tested together and why.