methotrexate + folinic acid

Methotrexate + folinic acid is a combination therapy used primarily to treat certain cancers and autoimmune diseases, most notably rheumatoid arthritis. Methotrexate is an antimetabolite and antifolate agent that inhibits enzymes involved in nucleotide synthesis, particularly dihydrofolate reductase, thymidylate synthase, aminoimidazole carboxamide ribonucleotide transformylase (AICART), and amido phosphoribosyltransferase. This inhibition prevents DNA synthesis and cell division, leading to its cytotoxic and anti-inflammatory effects[8]. In autoimmune diseases like rheumatoid arthritis, methotrexate also increases extracellular adenosine levels via AICART inhibition, resulting in anti-inflammatory activity[6][8]. Folinic acid (also known as leucovorin) is a reduced form of folic acid that bypasses the blockade of dihydrofolate reductase caused by methotrexate. It acts as a "rescue" agent by allowing normal cells to continue purine/pyrimidine synthesis even in the presence of methotrexate-induced enzyme inhibition[4][7][9]. The combination is used to reduce the toxic side effects of methotrexate—such as mucosal damage, gastrointestinal upset, liver toxicity, hematologic suppression—without significantly reducing its therapeutic efficacy for non-cancer indications[1][2].

Brand names

TrexallRheumatrexLeucovorinWellcovorin

Other names

methotrexate plus calcium folinatemethotrexate and leucovorinmethotrexate and folinic acidMTX + CF