How it is administered

Cytarabine is given as an injection and is not effective if taken by mouth. It can be administered in several ways:

• Intravenous (IV) infusion or injection: The medication is delivered directly into a vein, either as a slow drip (infusion) or as a quick injection.
• Subcutaneous injection: The medication is injected under the skin.
• Intrathecal injection: For certain types of leukemia, cytarabine can be injected directly into the fluid surrounding the brain and spinal cord (this is only done with preservative-free formulations).

The specific method, dose, and schedule will depend on the treatment plan created by your healthcare team.

How it works

Cytarabine is a type of chemotherapy medicine that works by interfering with the growth of cancer cells. It is especially effective against cells that are rapidly dividing, like those found in many blood cancers.

Cytarabine is classified as an antimetabolite. It closely resembles a natural building block of DNA, but when cancer cells try to use cytarabine to make new DNA, it disrupts the process. This prevents the cells from multiplying and eventually leads to their death. Cytarabine is most active during the S-phase of the cell cycle, when DNA is being copied. Because of this, it is particularly effective at targeting leukemia cells, which divide more quickly than most normal cells.

In addition to its direct effects on cancer cells, cytarabine can also suppress the immune system, which is why careful monitoring is needed during treatment.

Who Should take it

Cytarabine is used in combination with other chemotherapy drugs for the treatment of several types of blood cancers, including:

• Acute lymphoblastic leukemia (ALL)
• Acute non-lymphocytic (myeloid) leukemia (AML)
• Blast phase of chronic myelocytic leukemia (CML)
• Meningeal leukemia (leukemia involving the brain and spinal cord), via intrathecal administration

It is used for both adults and children. The exact treatment plan, including whether cytarabine is used and how it is given, depends on the specific type of leukemia, the stage of the disease, and other individual factors.

Who should not take it

Cytarabine should not be used by patients who are allergic to cytarabine or any of its components.

Cytarabine is a potent bone marrow suppressant, so it should be used with caution in patients who already have low blood cell counts due to previous treatments or other causes. It should also be used carefully in patients with impaired liver or kidney function, as these conditions can increase the risk of side effects.

Cytarabine can cause harm to an unborn baby, so it should not be used during pregnancy unless absolutely necessary. Women of childbearing potential should avoid becoming pregnant while on this medication. It is also not known if cytarabine passes into breast milk, so breastfeeding is generally not recommended during treatment.

Commonly used with

Cytarabine is most often used in combination with other chemotherapy drugs to treat leukemia. Common combinations include:

• Daunorubicin (as in the '7+3' regimen for AML)
• Vincristine, prednisone, and asparaginase (as part of multi-drug regimens for ALL)
• Methotrexate and hydrocortisone (for intrathecal therapy in meningeal leukemia)

The specific combination and schedule will depend on the type of leukemia and the treatment protocol.

Commonly tested with

Cytarabine is frequently studied in combination with other chemotherapy agents, such as daunorubicin, etoposide, and cyclophosphamide, in clinical trials for leukemia and other blood cancers.

It is also tested with supportive medications to manage side effects, such as corticosteroids for cytarabine syndrome or anti-nausea medications. In research settings, cytarabine may be combined with newer targeted therapies to improve outcomes in blood cancers.