Dosing and uses of Metanx (L-methylfolate/pyridoxal 5′-phosphate/methylcobalamin)
Adult dosage forms and strengths
L-methylfolate/pyridoxal 5′-phosphate/methylcobalamin
capsule
- 3mg/35mg/2mg
Diabetic Peripheral Neuropathy
Medical food for the clinical dietary management of endothelial dysfunction associated with diabetic peripheral neuropathy
1 capsule PO BID, or 2 capsules qDay
Pediatric dosage forms and strengths
Safety and efficacy not established
Metanx (L-methylfolate/pyridoxal 5′-phosphate/methylcobalamin) adverse (side) effects
Frequency not defined
L-methylfolate
- Allergic reactions
Pyridoxal 5′-phosphate
- Acne
- Skin reactions
- Allergic reactions
- Photosensitivity
- Nausea
- Vomiting
- Abdominal pain
- Loss of appetite
- Increased liver function test results
- Paresthesia
- Somnolence
- Nausea
- Headaches
Methylcobalamin
- Mild transient diarrhea
- Polycythemia vera
- Itching
- Transitory exanthema
- Edema
Warnings
Contraindications
Hypersensitivity to ingredients
Cautions
Contains milk, soy, and carmine
Daily folic acid administration (>0.1 mg/day), may obscure detection of B12 deficiency (specifically, the administration of folic acid may reverse the hematological manifestations of B12 deficiency, including pernicious anemia, while not addressing the neurological manifestations); L-methylfolate may be less likely than folic acid to mask vitamin B12 deficiency
Pregnancy and lactation
Pregnancy category: C
Lactation: Unknown whether distributed in breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Metanx (L-methylfolate/pyridoxal 5′-phosphate/methylcobalamin)
Mechanism of action
Provides nutritional requirements needed to restore metabolic processes associated with diabetic neuropathy to maintain blood flow by increasing nitric oxide resulting in vasodilation
L-methylfolate: Primary biologically active isomer of folic acid and the primary form of folate in circulation; folic acid is a precursor of tetrahydrofolic acid, which is involved as a cofactor for transformylation reactions
Pyridoxal 5′-phosphate (PLP): Active form of vitamin B6
Methylcobalamin: One of 2 forms of biologically active vitamin B12
Absorption
Peak plasma time: 1.3 hr
Peak plasma concentration: 129 ng/mL
AUC: 383 mcg•h/mL
Distribution
Protein bound: 56%
Vd: Wide distribution, RBC levels of folate remain elevated for periods in excess of 40 days following discontinuation of supplementation
Elimination
Half-life: 3 hr
Excretion: Primarily in urine
