Indications: Folinic acid is indicated for neutralizing the immediate toxic effects of folic acid antagonists such as methotrexate. Calcium folinate rescue is a treatment technique used in conjunction with folic acid antagonists to minimize systemic toxicity. It is also used in the treatment of megaloblastic anemias due to nutritional deficiency, pregnancy, infancy, liver disease, and malabsorption syndromes.

Composition: Each tablet contains:

Calcium Folinate Hydrate 6.249 mg equivalent to Folinic Acid 5 mg
Calcium Folinate Hydrate 10.746 mg equivalent to Folinic Acid 15 mg

Pharmacology: Calcium folinate is the calcium salt of folinic acid, the active metabolite of folic acid. It acts as a cofactor in one-carbon transfer reactions during the biosynthesis of purines and pyrimidines in nucleic acids. Deficiency of folic acid impairs thymidylate synthesis, leading to defective DNA synthesis and megaloblastic anemia. Folinic acid rapidly converts to tetrahydrofolate derivatives and serves as a potent antidote to the hematopoietic and gastrointestinal toxicity of folic acid antagonists such as methotrexate, pyrimethamine, and trimethoprim.

Dosage & Administration:

Folinic Acid Rescue: Should begin as soon as possible after inadvertent methotrexate overdose and within 24 hours of administration. Typical regimen: 15 mg (approx. 10 mg/m²) every 6 hours for 10 doses.
Megaloblastic anemia: 5–15 mg daily.
Children and adolescents: Safety and efficacy not established.
Neutralizing toxicity: Folinic acid dose may equal or exceed the methotrexate dose if overdose is suspected.

Interactions: High doses may counteract the antiepileptic effects of phenobarbital, phenytoin, and primidone, increasing seizure risk. Concurrent use with fluoropyrimidines has been associated with seizures and syncope.

Contraindications:

Known hypersensitivity to calcium folinate or any component
Pernicious anemia or other megaloblastic anemia due to vitamin B12 deficiency
Rare hereditary problems of galactose intolerance, lactase deficiency, or glucose-galactose malabsorption

Side Effects: Most common: mucositis, stomatitis, leukopenia, and/or diarrhea (dose-limiting).

Pregnancy & Lactation: No adequate studies in pregnant women. Should only be used if potential benefit outweighs risk. Unknown if excreted in human milk; caution advised in nursing mothers.

Precautions & Warnings:

Should only be used with methotrexate or 5-FU under supervision of an experienced clinician.
Must be administered promptly after folic acid antagonist overdose; delay beyond 4 hours may reduce effectiveness.
Should not be given simultaneously with folic acid antagonists to abort toxicity, as therapeutic effect may be nullified.
Adequate hydration and urine alkalinization are essential during methotrexate therapy.

Overdose Effects: No specific antidote. Excessive folinate may nullify the therapeutic effect of folic acid antagonists. Supportive care recommended.

Therapeutic Class: Supportive Care Therapy

Storage Conditions: Store below 30°C. Protect from light and keep out of reach of children.