. . "As leucovorin is a derivative of folic acid, it can be used to increase levels of folic acid under conditions favoring folic acid inhibition (following treatment of folic acid antagonists such as methotrexate). Leucovorin enhances the activity of fluorouracil by stabilizing the bond of the active metabolite (5-FdUMP) to the enzyme thymidylate synthetase."@en . . "6.2 hours"@en . "N-[4-({[(6S)-2-amino-5-formyl-4-oxo-1,4,5,6,7,8-hexahydropteridin-6-yl]methyl}amino)benzoyl]-L-glutamic acid"@en . . . . "# Jardine LF, Ingram LC, Bleyer WA: Intrathecal leucovorin after intrathecal methotrexate overdose. J Pediatr Hematol Oncol. 1996 Aug;18(3):302-4. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/8689347"@en . . . "(6S)-5-Formyl-5,6,7,8-tetrahydrofolic acid"@en . . . "Humans and other mammals"@en . . . "~15%"@en . . . "approved"@en . "The active metabolite of folic acid. Leucovorin is used principally as its calcium salt as an antidote to folic acid antagonists which block the conversion of folic acid to folinic acid. [PubChem]"@en . "Levoleucovorin"@en . . . . . . . . . . . . . . . . . . . . . . "Folinic acid"@en . . . "Leucovorin"@en . " "@en . . "(6S)-Leucovorin"@en . . . . " "@en . . . "(6S)-Folinic acid"@en . . . "Following oral administration, leucovorin is rapidly absorbed. The apparent bioavailability of leucovorin was 97% for 25 mg, 75% for 50 mg, and 37% for 100 mg."@en . . . . "(S)-Leucovorin"@en . "Levofolene"@en . . . . . . . "1492-18-8"@en . . "L-leucovorin"@en . . . . . . . . . . "James C. Wisowaty, Roy A. Swaringen, David A. Yeowell, \"Synthesis of leucovorin.\" U.S. Patent US4500711, issued July, 1955."@en . "L-Folinic acid"@en . "LD₅₀>8000 mg/kg (orally in rats). Excessive amounts of leucovorin may nullify the chemotherapeutic effect of folic acid antagonists."@en . . . . . . . . . . . . . . . . . . . . . . . . "For the treatment of osteosarcoma (after high dose methotrexate therapy). Used to diminish the toxicity and counteract the effects of impaired methotrexate elimination and of inadvertent overdosages of folic acid antagonists, and to treat megaloblastic anemias due to folic acid deficiency. Also used in combination with 5-fluorouracil to prolong survival in the palliative treatment of patients with advanced colorectal cancer."@en . . . . . . . . . . . "Levofolinic acid"@en . . . "Citrovorum factor"@en .