How it is administered

Cytarabine is administered as a sterile solution for intravenous (IV), subcutaneous (under the skin), or intrathecal (into the spinal fluid) injection. It is not effective if taken by mouth. The medication comes in various strengths and can be given as a continuous infusion, rapid IV injection, or subcutaneous injection, depending on the treatment plan. For certain types of leukemia involving the central nervous system, cytarabine may be given intrathecally using preservative-free preparations.

How it works

Cytarabine is a type of chemotherapy known as an antimetabolite. It works by interfering with the DNA synthesis of rapidly dividing cells, such as cancer cells. Cytarabine is especially effective during the S-phase of the cell cycle, when cells are actively replicating their DNA. Once inside the cell, cytarabine is converted into its active form, which inhibits an enzyme called DNA polymerase. This blocks the production of new DNA, preventing cancer cells from multiplying and leading to their death.

Cytarabine can also be incorporated into both DNA and RNA, causing further disruption of cellular function. Because it targets rapidly dividing cells, it can also affect normal cells that divide quickly, such as those in the bone marrow, which is why side effects like low blood counts are common.

Who Should take it

Cytarabine is indicated for use in combination with other approved anti-cancer drugs for remission induction in acute non-lymphocytic leukemia (such as acute myeloid leukemia, AML) in adults and children. It is also used in the treatment of acute lymphocytic leukemia and the blast phase of chronic myelocytic leukemia. For patients with leukemia that has spread to the central nervous system (meningeal leukemia), cytarabine can be given intrathecally for both treatment and prevention.

While cytarabine is not specifically approved for anaplastic large cell lymphoma, it is a cornerstone in the treatment of several blood cancers, especially various forms of leukemia, which may be relevant in cases where these diseases overlap.

Who should not take it

Cytarabine should not be used in patients who are hypersensitive (allergic) to the drug. Caution is needed in patients with pre-existing bone marrow suppression, as cytarabine is a potent bone marrow suppressant and can further lower blood counts. Patients with impaired liver or kidney function may require dose adjustments and close monitoring, as these conditions can increase the risk of toxicity.

Pregnant women should avoid cytarabine, as it can cause harm to the developing fetus. Women of childbearing potential should use effective contraception during treatment. Breastfeeding is not recommended while receiving cytarabine due to the potential for serious adverse reactions in nursing infants.

Commonly used with

Cytarabine is most often used in combination with other chemotherapy agents, such as daunorubicin, to achieve remission in acute leukemias. It may also be used with drugs like cyclophosphamide, vincristine, prednisone, methotrexate, and others, depending on the specific treatment protocol and type of leukemia or lymphoma being treated.

In the context of central nervous system involvement, cytarabine may be combined with methotrexate and hydrocortisone for intrathecal therapy.

Commonly tested with

Cytarabine is commonly tested in combination with other chemotherapy agents, particularly daunorubicin (as in the '7+3' regimen for AML) and other drugs used in multi-agent chemotherapy protocols for leukemia and lymphoma. It is also tested with supportive medications to manage side effects, such as antiemetics for nausea and medications to prevent or treat infections due to low blood counts.