<prompt> Folinic acid used in:Methotrexate toxicityCisplatin toxicityVincristine toxicity5FU toxicity  <response>: Ref: Goodman Gillmans 13th ed. P 1177 Folic acid is an essential dietary factor which is converted to FH4 by DHFR enzyme and provide methyl groups for the synthesis of precursors of DNA. Folic acid analogues such as MTX interfere with FH4 metabolism, thereby inhibiting DNA replication. Adverse effects: Myelosuppression, GI toxicity. Folinic acid Leucovorin can reverse toxic effects; used as rescue in high-dose therapy. Glucarpidase, a methotrexate-cleaving enzyme, is approved to treat toxicity. 