Folic acid
Mechanism :
An exogenous source of folate is required for nucleoprotein synthesis and the maintenance of normal erythropoiesis. Folic acid, whether given by mouth or parenterally, stimulates the production of red blood cells, white blood cells, and platelets in persons suffering from certain megaloblastic anemias.
Indication :
- Folate deficiency
- Hemolytic anemia
- Juvenile idiopathic arthritis
- Methotrexate induced nausea
- Megaloblastic anemia
- Methanol Deficiency
Contraindications :
Prior to therapy with folate, in megaloblastic anaemia, vitamin B12 deficiency must be excluded, as neuropathy may be precipitated.
Dosing :
Folic Acid Deficiency:
Infants: 15 mcg/kg/day OR 50 mcg/day either orally/IV/IM/SC.
1-10 years: 1 mg/day either orally/IV/IM/SC initially followed by 0.1-0.4 mg/day.
Methanol Toxicity:
1 mg/kg IV every 4 hours for 1 day.
Megaloblastic anemia due to folate deficiency:
Newborn:
1 mg oral, <1 year: 500 mcg/kg oral, 1-18 years: 5 mg daily once orally for 4 months.
Hemolytic Anemias:
Oral <12 years: 2.5 mg and 12-18 years: 10 mg once daily.
To limit
methotrexate associated side effects: Oral 2-18 years: 1 mg once daily.
Recommended Daily Allowance:
0-6 months:
65 mcg/day once orally.
7-12 months:
80 mcg/day once orally.
1-4 years:
150 mcg/day once orally; Max: 300 mcg/day once orally.
4-9 years:
200 mcg/day once orally; Max: 400 mcg/day once orally.
9-14 years:
300 mcg/day once orally.
14-18 years:
400 mcg/day once orally.
Adverse Effect :
Allergic sensitization, flushing, irritability, difficulty sleeping, malaise may occur rarely.
Interaction :
Sulfasalazine: May decrease phenytoin serum concentration, decrease absorption with sulfasalazine.
Folic Acid Antagonists: Prevent formation of active metabolite so ineffective for treating overdose of these drugs.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Dialysed. Dose as in normal renal function |
| HD | Dialysed. Dose as in normal renal function |
| HDF/High flux | Dialysed. Dose as in normal renal function |
| CAV/VVHD | Dialysed. Dose as in normal renal function |
Hepatic Dose :
No dosage adjustments are needed.