Leucovorin
Leucovorin (folinic acid) is a reduced form of folic acid that serves as a rescue agent following high-dose methotrexate chemotherapy and helps treat folic acid deficiency. It works by providing cells with reduced folate that bypasses the dihydrofolate reductase enzyme blocked by methotrexate, allowing normal DNA and RNA synthesis to resume. The medication is also used in combination with 5-fluorouracil for certain cancers and to prevent methotrexate toxicity in specific clinical situations.
Leucovorin is a folate supplement used to protect healthy cells from methotrexate toxicity and to enhance chemotherapy effectiveness.
Key facts at a glance
- RxNorm
- 6313
- Generic
- Leucovorin
- Class
- unclassified
- Brands
- Vykoura
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Routes
- oral
- Forms
- injection, tablet, solution
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Rescue therapy following high-dose methotrexate treatment, treatment of megaloblastic anemia due to folic acid deficiency, combination therapy with 5-fluorouracil for metastatic colorectal cancer, and prevention of methotrexate-induced organ toxicity.
Leucovorin is a reduced folate that enters the folate metabolic pathway without requiring reduction by dihydrofolate reductase, the enzyme inhibited by methotrexate. This allows normal cells to bypass methotrexate-induced folate depletion and resume DNA/RNA synthesis. When combined with 5-FU, it stabilizes the thymidylate synthase-5-FU complex, enhancing chemotherapy cytotoxicity.
Must be administered after methotrexate, not simultaneously, to ensure rescue of normal tissues. May mask vitamin B12 deficiency if used long-term. Contraindicated in patients with known hypersensitivity. May cause allergic reactions, GI upset, and (rarely) seizures at high doses. Calcium levels should be monitored in patients receiving 5-FU combinations.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 31, 2026. · Read our editorial policy