Mechanism of Action and Pharmacokinetics
Upon exogenous administration, Acidum folicum undergoes biological activation. In the liver, the drug is converted into its active form — tetrahydrofolic acid. It acts as a coenzyme and a donor of methyl and formyl groups, facilitating the transfer of one-carbon units in biosynthetic reactions.
Folates are critically essential for the synthesis of purine and pyrimidine bases, nucleotides (adenine, guanine, thymidylate), as well as for amino acid metabolism (methionine, serine, homocysteine). This triggers normal cell proliferation and the synthesis of DNA and RNA.
Pharmacological Effects
The primary effect of the drug is its antianemic action. Folic acid stimulates erythropoiesis by regulating the maturation of megaloblasts and normoblasts, and it improves iron absorption in the gastrointestinal tract.
The physiological role of the vitamin also involves supporting normal cell division, which is especially important during periods of increased bodily demand (such as pregnancy) and intensive tissue growth.
Clinical Indications
The drug is prescribed for the prevention and treatment of hypovitaminosis and avitaminosis, as well as for the following pathological conditions:
- Macrocytic hyperchromic anemia (folate deficiency).
- Megaloblastic $B_{12}$-deficiency anemia (strictly in combination with cyanocobalamin).
- Leukopenia and other types of anemia.
- Complex therapy for oncological, neurological, and gastroenterological diseases, as well as to reduce toxicity during tuberculosis treatment.
- Specific prevention of hyperhomocysteinemia.
Adverse Effects and Safety
The safety profile of folic acid is generally favorable, although allergic reactions may occur.
A critically important safety consideration is the restriction on monotherapy: in pernicious ($B_{12}$-deficiency) anemia, administering the drug in isolation is contraindicated. Although folic acid normalizes hematological blood parameters, it does not correct neurological symptoms, allowing severe neurological damage to progress unchecked.
Administration and Guidelines
Acidum folicum is available as powder and tablets of 1 mg (0.001 g).
The route of administration is oral (per os). The standard therapeutic dosage is 5 mg (0.005 g) daily. The course of treatment for deficiency states is typically 20–30 days.