What is "folinic acid"

n. A particular drug used in the treatment of cancer.

Folinic acid ( BAN) or leucovorin ( USAN), generally administered as the calcium or sodium salt (calcium folinate ( INN), sodium folinate, leucovorin calcium, leucovorin sodium), is an adjuvant used in cancer chemotherapy involving the drug methotrexate. It is also used in synergistic combination with the chemotherapy agent 5-fluorouracil.

Folinic acid (also called 5-formyltetrahydrofolate) was first discovered in 1948 as citrovorum factor and occasionally is still called by that name. Folinic acid should be distinguished from folic acid (vitamin B). However, folinic acid is a vitamer for folic acid, and has the full vitamin activity of this vitamin. It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.

Levofolinic acid and its salts are the 2S- form of the molecule. They are the only forms of the molecule that are known to be biologically active.