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MedBD
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Community data Updated 2 months ago
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Indications

Folistar is used to counteract the immediate toxic effects of folic acid antagonists such as methotrexate, and is central to calcium folinate rescue, a treatment technique in which calcium folinate is given alongside folic acid antagonists like methotrexate to minimise systemic toxicity. It is also used to treat megaloblastic anaemias arising from sprue, nutritional deficiency, pregnancy, infancy, liver disease and malabsorption syndrome.

⚠️ Always consult a registered physician before taking any medicine.

Pharmacology

Calcium Folinate Hydrate is the calcium salt of folinic acid, the 5-formyl derivative of tetrahydrofolic acid. It is a metabolite and active form of folic acid that acts as a cofactor for 1-carbon transfer reactions in the biosynthesis of purines and pyrimidines needed for nucleic acids. In patients with folic acid deficiency, impaired thymidylate synthesis is thought to underlie the defective DNA synthesis that leads to megaloblast formation and megaloblastic and macrocytic anemias. Because it converts readily to other tetrahydrofolic acid derivatives, folinate is a potent antidote for both the hematopoietic and reticuloendothelial toxic effects of folic acid antagonists such as methotrexate, pyrimethamine, and trimethoprim. In some cancers, folinate is thought to enter and "rescue" normal cells from the toxic effects of folic acid antagonists in preference to tumour cells, owing to differences in membrane transport mechanisms; this principle underlies high-dose methotrexate therapy with "folinate rescue."

Pregnancy & Breastfeeding

Pregnancy & Breastfeeding

There haven't been adequate, well-controlled studies of folinic acid in pregnant women, so it should be used during pregnancy only if the expected benefit outweighs the possible risk to the baby. It also isn't known whether the drug passes into breast milk. Since many medicines do pass into breast milk, calcium folinate should be given to a breastfeeding mother with caution.

⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

Dosage Reference

⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.

Adults: Folinic Acid rescue should begin as soon as possible after an inadvertent overdose and within 24 hours of methotrexate administration when there is delayed excretion. There are no fixed guidelines regarding the dose of methotrexate that triggers an automatic subsequent Folinic Acid administration, since tolerance to this folate antagonist depends on various factors. The dose of methotrexate varies, but folinate rescue is necessary when methotrexate is given at doses exceeding 500 mg/m2 and should be considered at doses of 100 mg to 500 mg/m2. Folinic Acid rescue treatment should commence approximately 24 hours after the start of the methotrexate infusion. Dosage regimens vary depending on the dose of methotrexate given. In general, Folinic Acid should be given at a dose of 15 mg (approximately 10 mg/m2) every 6 hours for 10 doses. The recommended dose of Folinic Acid to counter hematologic toxicity from folic acid antagonists with less affinity for mammalian dihydrofolate reductase than methotrexate, such as trimethoprim and pyrimethamine, is substantially lower, and 5 mg to 15 mg of Folinic Acid per day has been recommended. Neutralising the immediate toxic effects of folic acid antagonists: if overdose of methotrexate is suspected, the dose of Folinic Acid should be equal to or greater than the dose of methotrexate and should be given within one hour of the methotrexate administration. Megaloblastic anaemia (folate deficiency): 5 mg to 15 mg of Folinic Acid per day. Use in children and adolescents: the safety and efficacy of folinic acid in children and adolescents have not been established.

Side Effects & Interactions

Side Effects

No side-effect data recorded yet.