Folinic Acid (also known as leucovorin) is a reduced form of folic acid that does not require enzymatic conversion to become biologically active. It is commonly used in medicine to "rescue" normal cells from the toxic effects of high-dose chemotherapy, a strategy known as leucovorin rescue. Additionally, it is employed in combination with the anticancer drug 5-fluorouracil to enhance its therapeutic effect. Folinic acid is also used to treat certain types of anemia and to prevent folate deficiency in patients with malabsorption disorders. Unlike folic acid, it can directly participate in DNA synthesis and repair, making it particularly valuable in clinical settings where rapid folate activity is needed.
