folinic acid at a glance
Medicine class
Reduced folate and detoxifying agent for anticancer treatment
Main roles
Methotrexate rescue and combination treatment with fluorouracil
Administration
Given into a vein by injection or infusion under specialist supervision
Important warning
Folinic acid can increase fluorouracil toxicity, especially diarrhoea and mouth inflammation
What is folinic acid used for?
This product is licensed for specialist anticancer care.
Reducing toxicity and counteracting folate antagonists such as methotrexate in adults and children, including after overdose; this is called folinate rescue.
Use with fluorouracil in cytotoxic treatment.
How does folinic acid work?
Folinic acid supplies folate in a form that bypasses the enzyme blocked by methotrexate, helping restore folate-dependent cell processes. With fluorouracil, it stabilises inhibition of thymidylate synthase, increasing both anticancer activity and toxicity.
folinic acid preparations and strengths
Injection
Route: Parenteral
Strengths: 50 mg/mL
How to take folinic acid
This formulation is administered only into a vein by trained healthcare professionals. It may be given undiluted by injection or diluted for infusion. It must never be injected into the spinal canal.
Attend hospital appointments and follow the treatment team’s instructions.
Tell the team promptly about diarrhoea, mouth ulcers, vomiting or new seizures.
The solution is for single use and should be clear and free from visible particles.
folinic acid side effects
Common or expected effects
- With fluorouracil: mouth inflammation, diarrhoea, nausea or vomiting, reduced blood-cell production and hand-foot skin reactions.
- Folinic acid alone causes relatively few effects. Fever is uncommon; gastrointestinal or mood-related effects have been reported rarely.
Get urgent medical advice
- Severe or persistent diarrhoea, dehydration or extensive mouth inflammation, particularly with fluorouracil.
- Fever or other signs of infection associated with reduced blood-cell production.
- A severe allergic reaction, including breathing difficulty, swelling, hives or collapse.
- More frequent seizures in someone with epilepsy.
folinic acid in pregnancy
Evidence from controlled studies is limited. Folinic acid itself has not shown indications of harm and may be used when clinically necessary. Decisions depend on the risks of accompanying methotrexate, fluorouracil or another folate antagonist and require specialist review.
folinic acid while breastfeeding
It is unknown whether disodium folinate enters breast milk, although it may be used when clinically necessary. Methotrexate and fluorouracil are contraindicated during breastfeeding, so advice must consider the complete treatment regimen and be discussed with the specialist team.
folinic acid interactions
Folinic acid can oppose folate antagonists or intensify fluorouracil.
Fluorouracil
Folinic acid increases fluorouracil’s activity and toxicity, particularly gastrointestinal and blood-cell toxicity.
Methotrexate and other anticancer folate antagonists
Incorrectly coordinated folinic acid may reduce anticancer efficacy; rescue must be directed by methotrexate concentrations and the specialist protocol.
Cotrimoxazole or pyrimethamine
Folinic acid may reduce or completely neutralise their folate-antagonist effect.
Common questions about folinic acid
Answers are fully visible for fast scanning and source review.
Is folinic acid the same as folic acid?
No. Folinic acid is already a reduced, biologically active folate and can bypass the enzyme blocked by methotrexate; folic acid requires additional metabolic processing.
Why is folinic acid given with methotrexate?
It replenishes reduced folates in healthy cells and limits methotrexate toxicity while specialist monitoring preserves the intended anticancer effect.
Why is folinic acid combined with fluorouracil?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.