L-Methyl-B6-B12 (levomefolate calcium 3 mg pyridoxal phosphate anhydrous 35 mg methylcobalamin 2 mg) Dailymed

L-Methyl-B6-B12 Tablets is an orally administered medical food for the dietary management of endothelial dysfunction in patients with diabetic peripheral neuropathy.

Description

Each round coated purple colored tablet contains:
L-methylfolate Calcium	3 mg
Pyridoxal 5'-phosphate	35 mg
Methylcobalamin	2 mg

Ingredients

Dibasic Calcium Phosphate Dihydrate, Microcrystalline Cellulose 90, Pyridoxal-5'-Phosphate, Microcrystalline Cellulose HD 90, Opadry II Purple 40L10045 (Polydextrose, Titanium Dioxide, Hypromellose 3cP, Hypromellose 6cP, Glycerol Triacetate, Hypromellose 50cP, FD&C Blue #2, FD&C Red #40 and Polyglycol 8000), Microcrystalline Cellulose 50, Opadry II Clear Y-19-7483 (Hypromellose 6cP, Maltodextrin, Hypromellose 3cP, Polyglycol 400 and Hypromellose 50cP), Lmethylfolate Calcium, Magnesium Stearate, Methylcobalamin, and Carnauba Wax.

L-Methyl-B6-B12 Tablets do not contain sugar, lactose, yeast or gluten.

Pharmacology

L-methylfolate or 6(S)-5-methyltetrahydrofolate [6(S)-5-MTHF], is the primary biologically active diastereoisomer of folate¹ and the primary form of folate in circulation.² It is also the form which is transported across membranes into peripheral tissues³, particularly across the blood brain barrier.⁴ In the cell, 6(S)-5-MTHF is used in the methylation of homocysteine to form methionine and tetrahydrofolate (THF).¹ THF is the immediate acceptor of one carbon units for the synthesis of thymidine-DNA, purines (RNA and DNA) and methionine.⁵ About 70% of food folate and cellular folate is comprised of 6(S)-5-MTHF. Folic acid, the synthetic form of folate, must undergo enzymatic reduction by methylenetetrahydrofolate reductase (MTHFR) to become biologically active.⁶ Genetic mutations of MTHFR result in a cell's inability to convert folic acid to 6(S)-5- MTHF.⁷

Pyridoxal-5'-phosphate (PLP) is the active form of vitamin B₆ and is used as the prosthetic group for many of the enzymes where this vitamin is involved. PLP is readily absorbed by the intestine by a process which is preceded by dephosphorylation to form pyridoxal. The phosphate group is regained during passage through the intestine. Pyridoxine, the parent compound of PLP and the most frequently used form of vitamin B₆, requires reduction and phosphorylation before becoming biologically active. The PLP in L-Methyl-B6- B12 Tablets contains 25mg of pyridoxal (the active component of PLP).

Methylcobalamin (Methyl-B₁₂) is one of the two forms of biologically active vitamin B₁₂. Methyl-B₁₂ is the principal form of circulating vitamin B₁₂, hence the form which is transported into peripheral tissue. Methyl-B₁₂ is absorbed by the intestine by a specific mechanism which uses the intrinsic factor and by a diffusion process in which approximately 1% of the ingested dose is absorbed. Cyanocobalamin and hydroxycobalamin are forms of the vitamin that require conversion to methylcobalamin.

Pharmacokinetics

Absorption and Elimination

L-methylfolate is a water soluble molecule which is primarily excreted via the kidneys.⁸ In a study of subjects with coronary artery disease (n=21), peak plasma levels were reached in 1-3 hours following ORAL/PARENTERAL administration. Peak concentrations of L-methylfolate were found to be more than seven times higher than folic acid (129 ng ml^-1 vs. 14.1 ng ml^-1) following ORAL/PARENTERAL administration. The mean elimination halflife is approximately 3 hours for Lmethylfolate after the administration of 5mg of oral D,L-methylfolate. The mean values for C_max, T_max, and AUC_0-12 were 129 ng ml^-1, 1.3 hr., and 383 respectively.

Distribution

Red blood cells (RBCs) appear to be the storage depot for folate, as RBC levels remain elevated for periods in excess of 40 days following discontinuation of supplementation.¹⁰ Plasma protein binding studies showed that L-methylfolate is 56% bound to plasma proteins.

Indication And Usage

L-Methyl-B6-B12 Tablets are indicated for the distinct nutritional requirements of patients with endothelial dysfunction^9-11 who present with loss of protective sensation¹² and neuropathic pain^13-15 associated with diabetic peripheral neuropathy.

L-Methyl-B6-B12 Tablets are indicated for the distinct nutritional requirements of patients with endothelial dysfunction and/or hyperhomocysteinemia¹⁶ who present with lower extremity ulceration(s).^17-19

L-Methyl-B6-B12 Tablets should always be used under medical supervision.

Contraindications

There have been rare reports of hypersensitivity (allergic-like reactions) to L-Methyl-B6-B12 Tablets. Therefore, a known hypersensitivity to any of the components in the product is a contraindication to its use for any indication.

Precautions

General

Folic acid, when administered as a single agent in doses above 0.1mg daily, may obscure the 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.^20,21 Folate therapy alone is inadequate for the treatment of a B₁₂ deficiency.

Patient Information

L-Methyl-B6-B12 Tablets is a medical food²² to be used only under medical supervision.

Drug Interactions

L-Methyl-B6-B12 Tablets added to other Drugs

High dose folic acid may result in decreased serum levels for pyrimethamine and first-generation anticonvulsants (carbamazepine, fosphenytoin, phenytoin, phenobarbital, primidone, valproic acid, valproate).^23,24 This may possibly reduce first generation anticonvulsants effectiveness and/or increase the frequency of seizures in susceptible patients.^23,24 While the concurrent use of folic acid and first generation anticonvulsants or pyrimethamine may result in decreased efficacy of anticonvulsants, no such decreased effectiveness has been reported with the use of L-methylfolate. Nevertheless, caution should be used when prescribing L-Methyl-B6-B12 Tablets among patients who are receiving treatment with first generation anticonvulsants or pyrimethamine. Pyridoxal 5'-phosphate should not be given to patients receiving the drug levodopa, because the action of levodopa is antagonized by pyridoxal 5'-phosphate. However, pyridoxal 5'-phosphate may be used concurrently in patients receiving a preparation containing both carbidopa and levodopa. Capecitabine (Xeloda^®) toxicity may increase with the addition of leucovorin (5-formyltetrahydrofolate) (folate).

Drugs added to L-Methyl-B6- B12 Tablets

Antibiotics may alter the intestinal microflora and may decrease the absorption of methylcobalamin. Cholestyramine, colchicines or colestipol may decrease the enterohepatic reabsorption of methylcobalamin. Metformin, para-aminosalicylic acid and potassium chloride may decrease the absorption of methylcobalamin. Nitrous oxide can produce a functional methylcobalamin deficiency. Several drugs are associated with lowering serum folate levels or reducing the amount of active folate available. First generation anticonvulsants (carbamazepine, fosphenytoin, phenytoin, phenobarbital, primidone, valproic acid, valproate)^23,24 and lamotrigine²⁵ (a second-generation anticonvulsant) may decrease folate plasma levels. Information on other second-generation anticonvulsants impact on folate levels is limited and cannot be ruled out. Diavalproex sodium,²⁶ topiramate,²⁷ gabapentin,²⁸ pregabalin,²⁹ levetiracetam,³⁰ tiagabine,³¹ zonisamide,³² have not reported the potential to lower folate in their respective prescribing information. Methotrexate, alcohol (in excess), sulfasalazine, cholestyramine, colchicine, colestipol, L-dopa, methylprednisone, NSAIDs (high dose), pancreatic enzymes (pancrelipase, pancratin), pentamidine, pyrimethamine, smoking, triamterene, and trimethoprim may decrease folate plasma levels. Warfarin can produce significant impairment in folate status after a 6-month therapy.

Adverse Reactions

While allergic sensitization has been reported following both oral and parenteral administration of folic acid, allergic sensitization has not been reported with the use of L-Methylfolate Calcium. Paresthesia, somnolence, nausea and headaches have been reported with pyridoxal 5'-phosphate. Mild transient diarrhea, polycythemia vera, itching, transitory exanthema and the feeling of swelling of the entire body has been associated with methylcobalamin.

Dosage And Administration

The recommended dose is one tablet twice daily (B.I.D.) or as directed. L-Methyl-B6-B12 Tablets must be used under medical supervision.

How Supplied

L-Methyl-B6-B12 Tablets is available as a round coated purple colored tablet. Debossed with "V362" on one side and blank on the other. Commercial product is supplied in bottles of ninety (90) tablets.

Commercial Product (90 tablets)76439-362-90Virtus Pharmaceuticals, LLC does not represent this product code to be a National Drug Code (NDC) number. Instead, Virtus Pharmaceuticals, LLC has assigned a product code formatted according to standard industry practice to meet the formatting requirements of pharmacy and health insurance computer systems.

Use under medical/physician supervision.

Use under medical/physician supervision.

Storage

Store at controlled room temperature 15°C to 30°C (59°F to 86°F) (See USP). Protect from light and moisture. Dispense commercial product (90 tablets) in original light-resistant container. Dispense sample product in original bottle.

Patents

Some or all of the following patents may apply:

U.S. Patent No. 4,940,658U.S. Patent No. 5,563,126U.S. Patent No. 5,795,873U.S. Patent No. 5,997,915U.S. Patent No. 6,011,040U.S. Patent No. 6,207,651U.S. Patent No. 6,254,904U.S. Patent No. 6,297,224U.S. Patent No. 6,528,496and other pending patent applications.

References

¹ Donaldson, K. and K. JC., Naturally occurring forms of folic acid. II. Enzymatic conversion of methylenetetrahydrofolic acid to prefolic A-methyl-tetrahydrofolate. J Biol Chem, 1962. 237: p. 1298-304.

² Sweeney, M.R., J. McPartlin, and J. Scott. Folic acid fortification and public health: report on threshold doses above which unmetabolised folic acid appear in serum. BMC Public Health, 2007. 7: p. 41.

³ Wagner, C., Cellular folate binding proteins; function and significance. Annu Rev Nutr, 1982. 2: p. 229-48.

⁴ Spector, R. and A.V. Lorenzo. Folate transport in the central nervous system. Am J Physiol, 1975. 229(3): p. 777-82.

⁵ Selhub, J Folate, vitamin B12 and vitamin B6 and one carbon metabolism. J Nutr Health Aging, 2002. 6(1): p. 39-42.

⁶ Wright, A.J., J.R. Dainty, and P.M. Finglas. Folic acid metabolism in human subjects revisited: potential implications for proposed mandatory folic acid fortification in the UK. Br J Nutr, 2007: p. 1-9.

⁷ Chen, Z., A.C. Karaplis, S.L. Ackerman, I.P. Pogribny, S. Melnyk, S. Lussier-Cacan, M.F. Chen, A. Pai, S.W. John, R.S. Smith, T. Bottiglieri, P. Bagley, J. Selhub, M.A. Rudnicki, S.J. James, and R. Rozen. Mice deficient in methylenetetrahydrofolate reductase exhibit hyperhomocysteinemia and decreased methylation capacity, with neuropathology and aortic lipid deposition. Hum Mol Genet, 2001. 10(5): p. 433-43.

⁸5-Methy l tet rahydrofola te. (Monograph), Alternative Medicine Review, 2006. 11(4):330-337

⁹ Verhaar M. C., Wever Robert M.F., Kastelein John J.P., van Dam Thea, Koomans Hein A, Rabelink Ton J. 5- Methyltetrahydrofolate, the Active Form of Folic Acid, Restores Endothelial Function in Familial Hypercholesterolemia. Circulation 1998; 97:237-241.

¹⁰ van Etten R.W., de Koning E.J.P., Verhaar M.C., Gaillard A.J.M., Rabelink T.J. Impaired NO-dependent vasodilation in patients with Type II (non-insulin-dependent) diabetes mellitus is restored by acute administration of folate. Diabetologia 2002; 45:1004- 1010.

¹¹ Romerio S. C., Linder L., Nyfeler J., Wenk M., Litynsky P., Asmis R., Haefeli W. E. Acute hyperhomocysteinemia decreases NO bioavailability in healthy adults. Atherosclerosis 2004; 176:337-344.

¹² Walker MJ Jr, Morris LM. Increased cutaneous sensibility in patients with diabetic neuropathy utilizing a pharmacological approach-clinical case evidence. Clinical case Update: Vascular Disease Management 2007; 2(1):1-8.

¹³ Jacobs, Allen M. Abstracts of New Cardiovascular Horizons Meeting. Orally Administered Lmethylfolate, Methylcobalamin, and pyridoxal 5' –phosphate Reduces the Symptoms of Diabetic Peripheral Neuropathy. Oral Presentations 2008.

¹⁴ Jacobs, Allen M. Abstracts of New Cardiovascular Horizons Meeting. L-methylfolate, methylcobalamin, and pyridoxal 5' –phosphate supplementation to pregabalin partial responders for the treatment of painful diabetic neuropathy. Oral Presentations 2008.

¹⁵ Li G. Effect of Mecobalamin on Diabetic Neuropathies. Beijing Methycobal Clinical Trial Collaborative Group. Zhonghua Nei Ke Za Zhi 1999;38(1):14-17.

¹⁶ Ambrosch A. et al. Relation between homocysteinemia and diabetic neuropathy in patients with Type 2 diabetes mellitus. Diabet Med. 2001;18:185-192.

¹⁷ Veves A., Akbari C.M., Primavera J., Donaghue V.M., Zacharoulis D., Chrzan J.S., DeGirolami U., LoGerfo F.W., Freemen R. Endothelial Dysfunction and the Expression of Endothelias Nitric Oxide Synthetase in Diabetic Neuropathy, Vascular Disease and Foot Ulceration. Diabetes 1998;47:457-463.

¹⁸ Boykin J. V. Jr., Ischemic Vascular Disease, Nitric Oxide Deficiency, and Impaired Wound Healing. Vascular Disease Management 2007; 2(1) 1-8.

¹⁹ Boykin J. V. Jr., Byalis C, Homocysteine-A Stealth Mediator of Impaired Wound Healing: A Preliminary Study. Wounds 2006;18(4): 101-116.

²⁰ B Akoglu, M Schrott, H Bolouri, A Jaffari, E Kutschera, WF Caspary and D Faust: The Folic Acid Metabolite L-5-Methyltetrahydrofolate Effectively Reduces Total Serum Homocysteine Level in Orthotopic Liver Transplant Recipients: A Double-Blind Placebo- Controlled Study. European Journal of Clinical Nutrition (2007), 1-6

²¹ Scott JM, Weir DG: The Methylfolate Trap. A Physiological Response in Man to Prevent Methyl Group Deficiency in Kwashiokor and an Explanation for Folic-Acid- Induced Exacerbation of Subacute Combined Degeneration in Pernicious Anemia. Lancet. 1981 2:337-340

²² United States Food and Drug Administration Title 21 Code of federal Regulations 101.9(j)(8).

²³ PDR^® For Nutritional Supplements, 2001; ISBN: 1- 56363-364-7:157-167.

²⁴ Leucovorin Calcium (folinic acid) For Injection Prescribing Information: December 2003; Mayne Pharma (USA) Inc.

²⁵ Lamictal^® (lamotrigine) Prescribing Information: August 2005; Glaxo-SmithKline.

²⁶ Depakote^® (divalproex sodium) Prescribing Information: January 2006; Abbott Laboratories.

²⁷ Topamax^® (topiramate) Prescribing Information: June 2005; ORTHO-McNEIL NEUROLOGICS, INC.

²⁸ Neurontin^® (gabapentin) Prescribing Information: December 2005; Parke-Davis.

²⁹ Lyrica^® (pregabalin) Prescribing Information: March 2006; Parke- Davis.

³⁰ Keppra^® (levetiracetam) Prescribing Information: March 2007; UCB, Inc.

³¹ Gabitril (tiagabine) Prescribing Information: March 2005: Cephalon, Inc.

³² Zonegran^® (zonisamide) Prescribing Information: December 2004: Elan Pharma International Ltd.; licensed to Eisai Inc

Manufactured for:

Virtus Pharmaceuticals, LLCTampa, FL 33619

PC0293-00 Revised 11/14

Principal Display Panel - 90 Tablet Bottle Label

VIRTUS PHARMACEUTICALS

76439-362-90

L-METHYL-B6-B12

TABLETS

R_x 90 Tablets