Folinate

Folinate, also known as leucovorin, is a form of folic acid that is used medically. It is a metabolically active form of folate, meaning it does not require conversion by the body to become usable. Folinate is primarily used to reduce the toxicity of certain chemotherapy drugs, particularly methotrexate. Methotrexate is an antifolate drug that works by inhibiting enzymes involved in folate metabolism. While this inhibits cancer cell growth, it can also affect healthy cells. Folinate rescue, administered after high-dose methotrexate, provides a bypass mechanism for folate metabolism, thereby protecting healthy cells from the toxic effects of the drug.

Beyond its use in chemotherapy rescue, folinate is also employed in the treatment of megaloblastic anemia caused by folate deficiency. It is effective in restoring normal red blood cell production. Additionally, folinate can be used in combination with other drugs, such as fluorouracil, to enhance the efficacy of colorectal cancer chemotherapy. This combination therapy increases the stability of the enzyme thymidylate synthase, which is inhibited by fluorouracil, leading to a more potent anticancer effect. Folinate is available in both oral and injectable formulations. It is generally well-tolerated, with side effects being uncommon and usually mild.