displayName: DESCRIPTION SECTION
FDA Article Code: 34089-3
Folic acid, N-[ρ-[[(2-amino-4-hydroxy-6-pteridinyl) methyl]-amino]benzoyl]-L-glutamic acid, is a B complex vitamin containing a pteridine moiety linked by a methylene bridge to para-aminobenzoic acid, which is joined by a peptide linkage to glutamic acid. Conjugates of folic acid are present in a wide variety of foods, particularly liver, kidneys, yeast, and leafy green vegetables. Commercially available folic acid is prepared synthetically.
Folic acid occurs as a yellow or yellowish-orange crystalline powder and is very slightly soluble in water and insoluble in alcohol. Folic acid 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 (sodium folate). Aqueous solutions of folic acid 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 is as follows:
Each tablet, for oral administration, contains 1 mg folic acid.
Folic Acid Tablets, USP 1 mg contains the following inactive ingredients:
corn starch, microcrystalline cellulose, sodium starch glycolate and stearic acid.
displayName: CLINICAL PHARMACOLOGY SECTION
FDA Article Code: 34090-1
Folic acid acts on megaloblastic bone marrow to produce a normoblastic marrow.
In man, an exogenous source of folate is required for nucleoprotein synthesis and the maintenance of normal erythropoiesis.
Folic acid is a precursor of tetrahydrofolic acid, which is involved as a cofactor for transformylation reactions in the biosynthesis of
purines and thymidylates of nucleic acids. Impairment of thymidylate synthesis in patients with folic acid deficiency is thought to account
for the defective deoxyribonucleic acid (DNA) synthesis that leads to megaloblast formation and megaloblastic and macrocytic anemias.
Folic acid is absorbed rapidly from the small intestine, primarily from the proximal portion. Naturally occurring conjugated
folates are reduced enzymatically to folic acid in the gastrointestinal tract prior to absorption. Folic acid appears in the plasma approximately
15 to 30 minutes after an oral dose; peak levels are generally reached within 1 hour. After intravenous administration, the drug is rapidly cleared
from the plasma. Cerebrospinal fluid levels of folic acid are several times greater than serum levels of the drug. Folic acid is metabolized in the liver
to 7,8-dihydrofolic acid and eventually to 5,6,7,8-tetrahydrofolic acid with the aid of reduced diphosphopyridine nucleotide (DPNH) and folate reductases.
Tetrahydrofolic acid is linked in the N5 or N10 positions with formyl, hydroxymethyl, methyl, or formimino groups. N5-formyl tetrahydrofolic acid is leucovorin.
Tetrahydrofolic acid derivatives are distributed to all body tissues but are stored primarily in the liver. Normal serum levels of total folate have been reported to
be 5 to 15 ng/mL; normal cerebrospinal fluid levels are approximately 16 to 21 ng/mL. Normal erythrocyte folate levels have been reported to range from 175 to 316 ng/mL.
In general, folate serum levels below 5 ng/mL indicate folate deficiency, and levels below 2 ng/mL usually result in megaloblastic anemia.
After a single oral dose of 100 mcg of folic acid in a limited number of normal adults, only a trace amount of the drug appeared in the urine.
An oral dose of 5 mg in 1 study and a dose of 40 mcg/kg of body weight in another study resulted in approximately 50% of the dose appearing in the urine.
After a single oral dose of 15 mg, up to 90% of the dose was recovered in the urine. A majority of the metabolic products appeared in the urine after 6 hours;
excretion was generally complete within 24 hours. Small amounts of orally administered folic acid have also been recovered in feces. Folic acid is also
excreted in the milk of lactating mothers.
INDICATIONS AND USAGE
displayName: INDICATIONS & USAGE SECTION
FDA Article Code: 34067-9
Folic acid 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.
displayName: CONTRAINDICATIONS SECTION
FDA Article Code: 34070-3
Folic acid is contraindicated in patients who have shown previous intolerance to the drug.
displayName: WARNINGS SECTION
FDA Article Code: 34071-1
Administration of folic acid alone is improper therapy for pernicious anemia and other megaloblastic anemias in which vitamin B12 is deficient.
displayName: ADVERSE REACTIONS SECTION
FDA Article Code: 34084-4
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 reported
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 B12 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 in-vestigator reported decreased diphenylhydantoin
serum levels in folate-deficient patients receiving diphenylhydantoin who were treated with 5 mg or 15 mg of folic acid daily.
displayName: OVERDOSAGE SECTION
FDA Article Code: 34088-5
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 B12 may show reversion of the hematologic parameters to normal,
but neurologic manifestations due to vitamin B12 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.
DOSAGE AND ADMINISTRATION
displayName: DOSAGE & ADMINISTRATION SECTION
FDA Article Code: 34068-7
Oral administration is preferred. Although most patients with malabsorption cannot absorb food folates,
they are able to absorb folic acid 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 anemia due to vitamin B12 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 (regardless 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.
displayName: HOW SUPPLIED SECTION
FDA Article Code: 34069-5
NDC: 71335-0136-3 120 TABLET in a BOTTLE
NDC: 71335-0136-6 60 TABLET in a BOTTLE
NDC: 71335-0136-1 30 TABLET in a BOTTLE
NDC: 71335-0136-4 50 TABLET in a BOTTLE
NDC: 71335-0136-2 100 TABLET in a BOTTLE
NDC: 71335-0136-5 90 TABLET in a BOTTLE
Folic Acid 1mg Tablet
displayName: PACKAGE LABEL.PRINCIPAL DISPLAY PANEL
FDA Article Code: 51945-4