Folic Acid

FDA Classification

Rx

Formulation

Each capsule contains: Folic Acid 5mg

Preparation

Capsule

Therapeutic Class

Anti-Anaemic + Folic Acid

Product Description

Folic 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.

Folic Acid (Foliq) appears as light yellow to yellow to yellowish orange powder encapsulated in capsule size #3 with light green cap and light green body.

Indication

It is used in the treatment and prevention of the folate deficiency state. It is also used in women of child-bearing potential and pregnant women to protect against neural tube defects in their offspring.

Dosage and Method of Administration

For oral use only.

Folate- deficient megaloblastic anemia:

5 mg daily for 4 months, up to 15 mg daily may be necessary in malabsorption states or as prescribed by the physician.

Prophylaxis of megaloblastic anemia of pregnancy:

usual dose is 200 mcg to 500 mcg or up to 1 mg daily or as prescribed by the physician.

For women of child-bearing potential at high risk of having a pregnancy affected by neural tube defect:

4 to 5 mg daily starting before pregnancy and continued through the first trimester or as prescribed by the physician.

Pharmacokinetics

Folic acid is rapidly absorbed from the gastrointestinal tract, mainly from the duodenum and jejunum. Dietary folates are stated to have about half the bioavailability of crystalline folic acid. The naturally occurring folate polyglutamates are largely deconjugated and reduced by dihydrofolate reductase in the intestines to form 5-methyltetrahydrofolate, which appears in the portal circulation, where it is extensively bound to plasma proteins. Folic acid administered therapeutically enters the portal circulation largely unchanged since it is a poor substrate for reduction by dihydrofolate reductase. It is converted to the metabolically active form 5-methyltetrahydrofolate in the plasma and liver.

The principal storage site of folate is the liver; it is also actively concentrated in the cerebrospinal fluid.Folate undergoes enterohepatic circulation. Folate metabolites are eliminated in the urine and folate in excess of body requirements is excreted unchanged in the urine. Folate is distributed into breast milk. Folic acid is removed by hemodialysis.

Pharmacodynamics

Folic acid is reduced in the body to tetrahydrofolate, which is a coenzyme for various metabolic processes including the synthesis of purine and pyrimidine nucleotides, and hence in the synthesis of DNA; it is also involved in some amino-acid conversions, and in the formation and utilization of formate. Deficiency, which can result in megaloblastic anemia develops when the dietary intake is inadequate (as in malnutrition), when there is malabsorption (as in sprue), increased utilization (as in pregnancy or conditions such as hemolytic anemia), increased loss (as in hemodialysis), or as a result of the administration of folate antagonists and other drugs that interfere with normal folate metabolism.

Contraindication

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

Special Precaution

Folic acid should never be given alone or in conjunction with inadequate amounts of vitamin B12 for treatment of undiagnosed megaloblastic anemia, since folic acid may produce a hematopoietic response in patients with a megaloblastic anemia due to vitamin B12 deficiency without preventing aggravation of neurological symptoms. This masking of the true deficiency state can lead to serious neurological damage, such as subacute combined degeneration of the spinal cord.

Pregnancy and Lactation

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.

Studies in pregnant women have not shown that folic acid increases the risk of 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.

Warnings

Administration of folic acid alone is improper therapy for pernicious anemia and other megaloblastic anemias in which vitamin B12 is deficient.

Drug Interaction

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 phenytoin, 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 Lactobaciffus casei.

Adverse Reactions

Folic acid is relatively nontoxic in man. Gastrointestinal disturbances and hypersensitivity reactions have been reported rarely.

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 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.

Caution

Foods, Drugs, Devices and Cosmetics Act prohibits dispensing without prescription.

ADR Reporting Statement

“For suspected adverse drug reaction, report to the FDA: www.fda.gov.ph”Seek medical attention immediately at the first sign of any adverse drug reaction.

Storage Condition

Store at temperatures not exceeding 30°C.

Availability

Alu/Clear PVDC Blister Pack x 10’s (Box of 100’s)