{"code":"C642","name":"Methotrexate","terminology":"ncit","version":"26.09d","conceptStatus":"DEFAULT","leaf":true,"active":true,"definitions":[{"definition":"A drug used to treat some types of cancer, rheumatoid arthritis, and severe skin conditions, such as psoriasis. Amethopterin stops cells from making DNA and may kill cancer cells. It is a type of antimetabolite.","code":"P325","type":"ALT_DEFINITION","source":"NCI-GLOSS"},{"definition":"An antimetabolite and antifolate agent with antineoplastic and immunosuppressant activities. Methotrexate binds to and inhibits the enzyme dihydrofolate reductase, resulting in inhibition of purine nucleotide and thymidylate synthesis and, subsequently, inhibition of DNA and RNA syntheses. Methotrexate also exhibits potent immunosuppressant activity although the mechanism(s) of actions is unclear.","code":"P97","type":"DEFINITION","source":"NCI"}]}