Folic acid - instructions for use, dose, side effects, contraindications

Pharmacodynamics:Vitamin B (vitamin Bc, B9). In organism folic acid is reduced to tetrahydrofolic acid, which is a coenzyme involved in various metabolic processes. It is necessary for the normal maturation of megaloblasts and the formation of normoblasts. Stimulates erythropoiesis, participates in the synthesis of amino acids (including methionine, serine), nucleic acids, purines and pyrimidines, in the exchange of choline. In pregnancy folic acid is urgently needed, as has an important role in the development of neural tube, it is required for normal growth and development of the placenta. At normal levels of vitamin B9 probability of malformations in the fetus is significantly reduced (80% malformation can be prevented if the woman begins to compensate for the deficiency of vitamin B9 before conception).

Pharmacokinetics:The connection with plasma proteins is high. Deposited in the liver, where the biotransformation takes place (active form - tetrahydrofoliumth acid). The maximum concentration is 30-60 minutes. Elimination by the kidneys (unchanged appearance, metabolites). Removed during hemodialysis.

Indications:Megaloblastic anemia, caused by a deficiency of folic acid; tropical and non-tropical sprue, drug and radiation anemia and leukopenia, chronic gastroenteritis, intestinal tuberculosis, folic acid deficiency, including malnutrition, pregnancy, infancy and childhood.

ICD-10

I.A15-A19.A18 Tuberculosis of other organs

I.A15-A19.A18.3 Tuberculosis of the intestine, peritoneum and mesenteric lymph nodes

III.D50-D53.D52 Folic deficiency anemia

III.D55-D59.D59.0 Medicinal autoimmune hemolytic anemia

III.D55-D59.D59.2 Drug-induced non-autoimmune hemolytic anemia

III.D70-D77.D70 Agranulocytosis

XI.K50-K52.K52 Other non-infectious gastroenteritis and colitis

XI.K90-K93.K90.0 Celiac disease

XI.K90-K93.K90.1 Tropical sprue

XV.O20-O29.O25 Malnutrition in pregnancy

Contraindications:

Hypersensitivitytion.
Deficiency of cyanocobalamin.
Malignant neoplasms.
Deficiency of sugar.
Deficiency isomaltase.
Intolerance to fructose.
Glucose-galactosemalabsorption.
Children's age (up to 3 years).

Carefully:Pernicious and other megaloblastic anemia, accompanied by a deficiency of cyanocobalamin.

Pregnancy and lactation:

Recommendations for FDA - Category A. When taken in therapeutic doses, there is no change. Penetrates through the hematoplacental barrier. Fetal abnormalities in qualitative studies on humans are not recorded.

Penetrates into breast milk. In studies on humans, when taken in therapeutic doses, no changes were found.

Dosing and Administration:

Inside after meal.

For treatment of adults - 5 mg per day; children - in smaller doses depending on the age. The course of treatment is 20-30 days.

To prevent the deficiency of folic acid - 20-50 mcg per day.

In pregnancy - 400 mcg per day, during lactation - 300 mcg per day.

To prevent the development of fetal neural tube defects in the first trimester of pregnancy - 1 mg per day.

Side effects:

Allergic reactions: bronchospasm, erythema, fever, skin rashes.

Flatulence, anorexia, closure, depression, difficulty concentrating, anxiety, irritability, nausea, unpleasant aftertaste (when taken at a dose exceeding 15 mg per day).

With prolonged use, it is possible to develop hypovitaminosis B12.

Overdose:The dose of folic acid to 4-5 mg is tolerated well. Higher doses can cause abnormalities in the central nervous system and gastrointestinal tract. Treatment symptomatic.

Interaction:

Analgesics, anticonvulsants (hydantoin, carbamazepine, phenobarbital, primidon), estrogens, oral contraceptives increase the need for folic acid.

Folic acid reduces the effect of hydantoin anticonvulsants, so it is necessary to increase the dose of hydantoin.

Antacids containing aluminum, magnesium; chloramphenicol, neomycin, polymyxin, tetracyclines reduce the absorption of folic acid (taking 2 hours before or after taking folic acid is necessary).

Kolestyramin breaks the absorption of folic acid (it is necessary to take 2 hours before or 4-6 hours after receiving kolestiramina).

Methotrexate, pyrimethamine, triamterene, trimethoprim inhibit dihydrofolate reductase, therefore, instead of folic acid, calcium leucovorin or calcium folinate.

Sulfonamides (including sulfosalazine) inhibit the absorption of folate, so the dose of folic acid should be increased.

Folic acid reduces the effect of phenytoin (an increase in its dose is required).

The use of zinc-containing preparations together with folic acid leads to a decrease in zinc absorption.

Special instructions:Prevents the development of neural tube defects in newborns (when taken by the mother in the first 12 weeks) and side effects caused by taking methotrexate in patients with arthritis.

Folic acid is not used for treatment of B12-deficient (pernicious), normocytic and aplastic anemia, as well as anemia, refractory to treatment. With pernicious (B12-deficient) anemia folic acid, improving hematologic indices, masks neurological complications. Until pernicious anemia is excluded, administration of folic acid in doses exceeding 0.1 mg per day is not recommended (exceptions - pregnancy and lactation).

Does not affect the frequency of seizures and the development of side effects of antiepileptic drugs in patients with epilepsy.

When using large doses of folic acid, as well as treatment over a long period, a decrease in vitamin concentration is possible.

In most cases, the deficiency of folic acid is restored independently or after a short course of treatment.

Antibiotics can distort (give knowingly underestimated indicators) the results of a microbiological evaluation of the concentration of folic acid in plasma and erythrocytes.

The use of the drug does not affect the ability to drive vehicles and engage in other potentially hazardous activities that require increased concentration and speed of psychomotor reactions.

Instructions

Folic acid (Acidum folicum)