Name
FOLIC ACID
Mode of Action
IN HUMANS, AN EXOGENOUS SOURCE OF FOLIC ACID IS REQUIRED FOR NUCLEOPROTEIN SYNTHESIS AND THE MAINTENECE OF NORMAL ERYTHROPOIESIS.
Dosage
FOR THE TREATMENT OF FOLATE-DEFICIENT MEGALOBLASTIC ANAEMIA IT IS RECOMMENDED IN THE UK THAT FOLIC ACID IS GIVEN ORALLY IN DOSES OF 5 MG DAILY FOR 4 MONTHS; UP TO 15 MG DAILY MAY BE NECESSARY IN MALABSORPTION STATES. CONTINUED ORAL DOSAGE WITH FOLIC ACID 5 MG EVERY 1 TO 7 DAYS MAY BE NECESSARY IN CHRONIC HAEMOLYTIC STATES SUCH AS THALASSAEMIA MAJOR OR SICKLE-CELL ANAEMIA, DEPENDING ON THE DIET AND RATE OF HAEMOLYSIS; SIMILAR DOSES MAY BE NECESSARY IN SOME PATIENTS RECEIVING RENAL DIALYSIS IN ORDER TO PREVENT DEFICIENCY. THE BNFC RECOMMENDS AN ORAL DOSE OF 500 MICROGRAMS/KG ONCE DAILY FOR FOLATE-DEPENDENT MEGALOBLASTIC ANAEMIA IN CHILDREN UP TO THE AGE OF 1 YEAR; OLDER CHILDREN MAY BE GIVEN SIMILAR DOSES TO THOSE IN ADULTS. FOR PROPHYLAXIS OF FOLATE DEFICIENCY IN CHILDREN ON DIALYSIS IT SUGGESTS 250 MICROGRAMS/KG ONCE DAILY BY MOUTH FROM 1 MONTH TO 12 YEARS OF AGE, AND 5 TO 10 MG DAILY IN OLDER CHILDREN. IN THE USA THE USUAL RECOMMENDED THERAPEUTIC DOSE FOR FOLATE DEFICIENCY IS LOWER; FOLIC ACID 0.25 TO 1 MG DAILY BY MOUTH IS SUGGESTED UNTIL A HAEMATOPOIETIC RESPONSE HAS BEEN OBTAINED, ALTHOUGH SOME PATIENTS REQUIRE HIGHER DOSES, ESPECIALLY IN MALABSORPTION STATES. THE USUAL MAINTENANCE DOSE IS 400 MICROGRAMS DAILY. IN THE PROPHYLAXIS OF MEGALOBLASTIC ANAEMIA OF PREGNANCY, THE USUAL DOSE IS 200 TO 500 MICROGRAMS DAILY IN THE UK. FOR WOMEN OF CHILD-BEARING POTENTIAL AT HIGH RISK OF HAVING A PREGNANCY AFFECTED BY NEURAL TUBE DEFECT, THE DOSE OF FOLIC ACID IS 4 OR 5 MG DAILY STARTING BEFORE PREGNANCY (IN THE USA THE RECOMMENDATION IS 4 WEEKS BEFORE) AND CONTINUED THROUGH THE FIRST TRIMESTER. FOR OTHER WOMEN OF CHILD-BEARING POTENTIAL THE DOSE IS 400 MICROGRAMS DAILY.
Drug Group
[VITAMIN] , [FOLIC ACID]
Cross Reaction
FOLATE DEFICIENCY MAY BE PRODUCED BY NUMBER OF DRUGS LIKE ANTIEPILEPTICS, ORAL CONTRACEPTIVES, ANTITUBERCULAR DRUGS, ALCOHOL AND FOLIC ACID ANTAGONISTS LIKE AMINOPTERIN, METHOTREXATE, PYRIMETHAMINE, TRIMETHOPRIM, SULPHONAMIDES.
Drug Interaction
Drugs Side Effect
Drug Categories
Special Precaution
Drug Safety
Monograph