What is the primary therapeutic class of methotrexate?

Methotrexate is classified primarily as an antimetabolite. This classification is based on its mechanism of action, which involves inhibiting enzymes that are crucial for DNA synthesis and cell replication. Specifically, methotrexate interferes with the metabolism of folate, a B vitamin that is essential for the formation of nucleotides, the building blocks of DNA. By blocking the conversion of folate into its active forms, methotrexate effectively hampers the proliferation of rapidly dividing cells, such as cancer cells, making it a vital drug in the treatment of various malignancies, including leukemia and other solid tumors.

In addition to its oncology applications, methotrexate is also used in lower doses to manage autoimmune diseases by modulating the immune response. This dual action as an antitumor and immunosuppressive agent underscores its versatility in clinical use.

Understanding the primary therapeutic class helps clinicians to categorize the drug appropriately and anticipate its interactions with other medications, as well as its side effects and necessary monitoring parameters.