Folinic Acid

Introduction: Folinic Acid (Calcium folinate) is a metabolite and active form of folic acid. It is used to neutralize the toxic effects of folic acid antagonists (such as methotrexate) and for the treatment of megaloblastic anemia.

How it works: Folinic acid enters the cells as 5-methyl tetrahydrofolate and supplies the cofactor blocked by methotrexate. It aids in DNA synthesis and neutralises the effects of folic acid antagonists.

Important Information: In cases of methotrexate overdosage, folinate should be administered as soon as possible. If a period exceeding 4 hours intervenes, the treatment may not be effective.

• Neutralising the immediate toxic effects of folic acid antagonists - e.g., methotrexate
• Calcium folinate rescue - using calcium folinate in conjunction with folic acid antagonists to minimise systemic toxicity
• Treatment of megaloblastic anaemias due to sprue, nutritional deficiency, pregnancy, infancy, liver disease and malabsorption syndrome

Supportive Care Therapy

Folic acid derivative

Folinic acid (5-formyl derivative of tetrahydrofolic acid) is a metabolite and active form of folic acid that is involved as a cofactor for 1-carbon transfer reactions in the biosynthesis of purine and pyrimidines of nucleic acids. Impairment of thymidylate synthesis in patients with folic acid deficiency leads to defective DNA synthesis that results in megaloblast formation and megaloblastic anemias. Folinate is a potent antidote for hematopoietic and reticuloendothelial toxic effects of folic acid antagonists (e.g., methotrexate, pyrimethamine, trimethoprim).

Folinic acid is converted to tetrahydrofolate to supply the cofactor blocked by methotrexate, which helps restart DNA synthesis and protect normal cells from toxicity.

Folinic Acid Rescue:

• Required when methotrexate is given at doses exceeding 500 mg/m2.
• Start approximately 24 hours after the beginning of methotrexate infusion.
• Generally 15 mg (approximately 10 mg/m2) every 6 hours for 10 doses.

Neutralising Methotrexate Toxicity:

• Dose of Folinic Acid should be equal to or greater than the dose of methotrexate.
• Administer within one hour of methotrexate administration.

Megaloblastic anaemia (folate deficiency):

• 5 mg to 15 mg per day.

Children and adolescents: Safety and efficacy have not been established.

* Use as directed by the registered physician

Oral tablet. Can be taken with or without food. Swallow whole. In cases of methotrexate overdosage, administer as soon as possible.

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and follow your regular schedule.

Common Side Effects:

• Mucositis
• Stomatitis
• Leukopenia
• Diarrhea
• Allergic sensitisation
• Rash
• Pruritus
• Nausea
• Vomiting
• Pyrexia

Precautions:

• Use under the direct supervision of a clinician experienced in cancer chemotherapeutic agents.
• Caution in undiagnosed megaloblastic anaemia and folate dependent tumors.
• Ensure prompt excretion of methotrexate by alkalinising urine (pH >7.0) and increasing fluid intake.

Contraindications:

• Hypersensitivity to calcium folinate
• Pernicious anemia or other megaloblastic anemia where vitamin B12 is deficient
• Galactose intolerance, lapp lactase deficiency or glucose-galactose malabsorption

Drug Interactions:

• Large amounts of folinates may counteract the antiepileptic effect of phenobarbitone, phenytoin and primidone and increase seizure frequency.
• Caution with fluoropyrimidine (associated with seizures and syncope).

Food Interactions: No interaction found/established.

Use in Pregnancy: No adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to the fetus.

Use in Lactation: Unknown if excreted in human milk. Caution should be exercised.

Pediatric Use: Safety and efficacy in children and adolescents have not been established.

Geriatric Use: No specific dosage adjustment is necessary for elderly patients. Use with caution.

Renal & Hepatic Impairment: No known restrictions. However, consult your doctor.

Overdose: Excessive amounts may nullify the chemotherapeutic effect of folic acid antagonists. No specific antidote. Give appropriate supportive care.

Storage: Do not store above 30°C. Keep away from light and out of reach of children.

Folinic Acid Tablet