What is Methotrexate classified as?

Methotrexate is classified as an antimetabolite, which means it interferes with the normal metabolic processes within cells, particularly those involved in the synthesis of nucleotides. It is primarily used in the treatment of various cancers, as well as autoimmune diseases, by hindering the proliferation of rapidly dividing cells like cancer cells.

As an antimetabolite, methotrexate specifically inhibits the enzyme dihydrofolate reductase, which is necessary for the conversion of dihydrofolate to tetrahydrofolate, a process crucial for DNA synthesis and cell division. By disrupting folate metabolism, methotrexate effectively restricts the growth of cancer cells.

In contrast, alkylating agents work by directly damaging DNA, disrupting the replication of cancer cells through a different mechanism. Targeted therapies aim at specific molecules involved in cancer growth and progression, while hormonal therapies focus on influencing hormone-driven cancers. Each of these classifications operates under distinct principles and mechanisms, making methotrexate's role as an antimetabolite particularly significant in chemotherapy regimens.