What type of chemotherapy agent would not typically be classified as alkylating?

Antimetabolites are not classified as alkylating agents because they work through a different mechanism. While alkylating agents, such as nitrogen mustards and nitrosoureas, exert their effects by directly damaging DNA through the addition of alkyl groups, antimetabolites interfere with DNA and RNA synthesis by mimicking the structure of natural metabolites. This leads to disruption in cell division and proliferation, particularly in rapidly dividing cancer cells.

Antimetabolites inhibit enzymes involved in nucleotide synthesis or get incorporated into DNA and RNA, which prevents normal function and leads to cell death. Their action is primarily based on competing with natural substrates, rather than causing DNA cross-linking or direct damage, which is characteristic of alkylating agents. Therefore, antimetabolites represent a distinct class of chemotherapy agents with unique mechanisms of action.