Tsütarabiin

Tsütarabiin, also known as cytosine arabinoside or Ara-C, is a chemotherapy drug used in the treatment of various cancers, particularly hematological malignancies like acute myeloid leukemia (AML) and lymphoma. It is an antimetabolite, meaning it interferes with the normal metabolic processes of cells. Specifically, tsütarabiin is a pyrimidine analog that mimics the natural nucleoside deoxycytidine. Once inside the cell, it is phosphorylated into its active form, tsütarabiin triphosphate. This active metabolite then inhibits DNA synthesis by competing with deoxycytidine triphosphate for incorporation into DNA. Furthermore, it can also inhibit DNA polymerase, an enzyme crucial for DNA replication.

The administration of tsütarabiin is typically intravenous or subcutaneous. Its effectiveness is primarily seen in rapidly dividing cells, such as cancer cells, which are more susceptible to DNA synthesis inhibition. However, this mechanism also leads to side effects, as healthy rapidly dividing cells, like those in bone marrow, hair follicles, and the gastrointestinal tract, can also be affected. Common side effects include bone marrow suppression, leading to anemia, neutropenia, and thrombocytopenia, which can increase the risk of infection and bleeding. Nausea, vomiting, diarrhea, and hair loss are also frequently observed. Tsütarabiin is generally not effective against solid tumors. Its use requires careful monitoring of blood counts and other vital signs due to its potential toxicity.