Folic Acid

Description

DESCRIPTION Folic acid, USP, N-[ p -[[(2-amino-4- hydroxy-6-pteridinyl methyl]- amino] benzoyl]-Lglutamic acid, is a B complex vitamin containing apteridine moiety linked by a methylene bridge to para -aminobenzoic acid, which is joined by a peptide linkage to glutamic acid. Conjugates of folic acid, USP are present in a wide variety of foods, particularly liver, kidneys, yeast, and leafy green vegetables. Commercially available folic acid, USP is pre pared synthetically. Folic acid, USP occurs as a yellow or yellowish-orange crystalline powder and is very slightly soluble in water and insoluble in alcohol. Folic acid, USP is readily soluble in dilute solutions of alkali hydroxides and carbonates, and solutions of the drug may be prepared with the aid of sodium hydroxide or sodium carbonate, thereby forming the soluble sodium salt of folic acid, USP (sodium folate). Aqueous solutions of folic acid, USP are heat sensitive and rapidly decompose in the presence of light and/or riboflavin; solutions should be stored in a cool place protected from light. The structural formula of folic acid, USP is as follows: C 19 H 19 N 7 O 6 M.W. 441.40 Each tablet, for oral administration, contains 1 mg folic acid, USP Folic acid tablets, USP 1 mg contain the following inactive ingredients: lactose monohydrate, microcrystalline cellulose, sodium starch glycolate and stearic acid.

What Is Folic Acid Used For?

INDICATIONS & USAGE Folic acid, USP is effective in the treatment of megaloblastic anemias due to a deficiency of folic acid (as may be seen in tropical or nontropical sprue) and in anemias of nutritional origin, pregnancy, infancy, or childhood.

Dosage and Administration

DOSAGE & ADMINISTRATION Oral administration is preferred. Although most patients with malabsorption cannot absorb food folates, they are able to absorb folic acid, USP given orally. Parenteral administration is not advocated but may be necessary in some individuals (e.g., patients receiving parenteral or enteral alimentation). Doses greater than 0.1 mg should not be used unless ane mia due to vitamin B 12 deficiency has been ruled out or is being adequately treated with a cobalamin. Daily doses greater than 1 mg do not enhance the hematologic effect, and most of the excess is excreted unchanged in the urine. The usual therapeutic dosage in adults and children (regard less of age) is up to 1 mg daily. Resistant cases may require larger doses. When clinical symptoms have subsided and the blood picture has become normal, a daily maintenance level should be used, i.e., 0.1 mg for infants and up to 0.3 mg for children under 4 years of age, 0.4 mg for adults and children 4 or more years of age, and 0.8 mg for pregnant and lactating women, but never less than 0.1 mg/day. Patients should be kept under close supervision and adjustment of the maintenance level made if relapse appears imminent. In the presence of alcoholism, hemolytic anemia, anticonvulsant therapy, or chronic infection, the maintenance level may need to be increased.

Side Effects (Adverse Reactions)

ADVERSE REACTIONS Allergic sensitization has been reported following both oral and parenteral administration of folic acid. Folic acid is relatively nontoxic in man. Rare instances of allergic responses to folic acid preparations have been report ed and have included erythema, skin rash, itching, general malaise, and respiratory difficulty due to bronchospasm. One patient experienced symptoms suggesting anaphylaxis following injection of the drug. Gastrointestinal side effects, including anorexia, nausea, abdominal distention, flatulence, and a bitter or bad taste, have been reported in patients receiving 15 mg folic acid daily for 1 month. Other side effects reported in patients receiving 15 mg daily include altered sleep patterns, difficulty in concentrating, irritability, overactivity, excitement, mental depression, confusion, and impaired judgment. Decreased vitamin B 12 serum levels may occur in patients receiving prolonged folic acid therapy. In an uncontrolled study, orally administered folic acid was reported to increase the incidence of seizures in some epileptic patients receiving phenobarbital, primidone, or diphenylhydantoin. Another investigator reported decreased diphenylhydantoin serum levels in folate-deficient patients receiving diphenylhydantoin who were treated with 5 mg or 15 mg of folic acid daily.

Drug Interactions

Drug Interactions There is evidence that the anticonvulsant action of phenytoin is antagonized by folic acid. A patient whose epilepsy is completely controlled by phenytoin may require increased doses to prevent convulsions if folic acid is given. Folate deficiency may result from increased loss of folate, as in renal dialysis and/or interference with metabolism (e.g., folic acid antagonists such as methotrexate); the administration of anticonvulsants, such as diphenylhydantoin, primidone, and barbiturates; alcohol consumption and, especially, alcoholic cirrhosis; and the administration of pyrimethamine and nitrofurantoin. False low serum and red cell folate levels may occur if the patient has been taking antibiotics, such as tetracycline, which suppress the growth of Lactobacillus casei.

Contraindications

CONTRAINDICATIONS Folic acid, USP is contraindicated in patients who have shown previous intolerance to the drug.

Pregnancy and Breastfeeding

Pregnancy Teratogenic Effects Pregnancy Category A Folic acid is usually indicated in the treatment of megaloblastic anemias of pregnancy. Folic acid requirements are markedly increased during pregnancy, and deficiency will result in fetal damage (see INDICATIONS AND USAGE). Studies in pregnant women have not shown that folic acid increases the risk of fetal abnormalities if administered during pregnancy. If the drug is used during pregnancy, the possibility of fetal harm appears remote. Because studies cannot rule out the possibility of harm, however, folic acid should be used during pregnancy only if clearly needed.

Nursing Mothers Folic acid is excreted in the milk of lactating mothers. During lactation, folic acid requirements are markedly increased; however, amounts present in human milk are adequate to fulfill infant requirements, although supplementation may be needed in low- birth-weight infants, in those who are breast-fed by mothers with folic acid deficiency (50 mcg daily), or in those with infections or prolonged diarrhea.

Overdosage

OVERDOSAGE Except during pregnancy and lactation, folic acid should not be given in therapeutic doses greater than 0.4 mg daily until pernicious anemia has been ruled out. Patients with pernicious anemia receiving more than 0.4 mg of folic acid daily who are inadequately treated with vitamin B 12 may show reversion of the hematologic parameters to normal, but neurologic manifestations due to vitamin B 12 deficiency will progress. Doses of folic acid exceeding the Recommended Dietary Allowance (RDA) should not be included in multivitamin preparations; if therapeutic amounts are necessary, folic acid should be given separately.

How Supplied

HOW SUPPLIED Folic Acid Tablets, USP 1 mg are supplied as yellow, round, biconvex uncoated tablets, debossed with "C3" on one side and breakline on other side and supplied in bottles of 100 and 1000. Folic Acid Tablets, USP 1 mg is having functional scoring. They are available as follows: Bottles of 100s: NDC 72241-050-05 Bottles of 1000s: NDC 72241-050-11 Dispense in well-closed container with child-resistant closure. Store at 20°to 25°C (68°to 77°F) [See USP Controlled Room Temperature]. Manufactured by: Cadila Pharmaceuticals Limited, 1389, Trasad Road, Dholka-382225 Dist.: Ahmedabad, Gujarat, INDIA Manufactured for: Modavar Pharmaceuticals LLC. 1016, 16th Street, Suite 602, Washington, DC 20036 Toll free number: 800 688 4697 Revised: March, 2023