A derivative of folic acid involved in purine synthesis. Administered by mouth or by injection or infusion in the form of its calcium or disodium salts, it is used to reverse the biological effects of methotrexate and other dihydrofolate reductase inhibitors and so to prevent excessive toxicity. This action is termed folinic acid rescue. Folinic acid has a potentiating effect with fluorouracil, with which it is often used. Trade names: Isovorin, Refolinon, Sodiofolin.
Subjects: Medicine and Health — Chemistry.