Which of the following is a common pediatric antimetabolite drug?

Cytarabine is recognized as a common antimetabolite drug used in pediatric oncology, particularly for treating acute lymphoblastic leukemia (ALL) and other hematologic malignancies. Antimetabolites are a class of chemotherapy drugs that interfere with the synthesis of nucleotides, which are essential for DNA and RNA production. By disrupting these processes, Cytarabine effectively inhibits the proliferation of cancer cells.

This drug is particularly utilized in pediatric cases due to its efficacy and the specific types of cancers commonly found in children. Its mechanism involves competing with the normal nucleoside cytidine, leading to the incorporation of the drug into the DNA strand, causing chain termination and cell death in rapidly dividing cancer cells.

Other choices, while they are indeed chemotherapy agents, do not classify as common antimetabolites or are used less frequently in the pediatric population for the treatment of hematological cancers. For instance, oxaliplatin is primarily used for colorectal cancers; vincristine is a vinca alkaloid used in treating a variety of cancers but is not an antimetabolite; and docefaction appears to be a typographical error and likely refers to docetaxel, which is generally used in adult cancers rather than pediatric cases.