What describes the primary action of Xeloda (capecitabine)?

The primary action of Xeloda (capecitabine) is that it functions as a pyrimidine antimetabolite. As a chemotherapeutic agent, capecitabine is designed to interfere with the synthesis of nucleic acids, particularly those involved in DNA and RNA production. This is crucial because cancer cells are highly dependent on rapid DNA replication to sustain their uncontrolled growth.

Capecitabine is a prodrug that gets converted into the active metabolite 5-fluorouracil (5-FU) in the body. This active form mimics the natural substrate for enzymes involved in the pyrimidine synthesis pathway, which disrupts normal metabolic processes within the cancer cells. By inhibiting the enzyme thymidylate synthase, 5-FU impedes the production of thymidine, a vital component of DNA, thereby leading to the inhibition of cell division and triggering cancer cell apoptosis.

In contrast, the other options define different classes of medications. Alkylating agents work by directly damaging DNA, topoisomerase inhibitors interfere with the enzymes that alter DNA supercoiling necessary for replication, and taxane derivatives stabilize microtubules preventing cell division. Each of these classes has a unique mechanism that is not