Full Prescribing Info
Each film coated tablet contains: Methylcobalamin 500 mcg.
Excipients/Inactive Ingredients: Microcrystalline cellulose, pregelatinised starch, povidone, isopropyl alcohol, colloidal silicon dioxide, purified talc, stearic acid, ethyl cellulose, titanium dioxide, polyethylene glycol, dichloromethane, opadry brown 03F565012.
Pharmacotherapeutic Group: Vitamin, Antianemic. ATC code: B03BA05.
Pharmacology: Pharmacodynamics: Methydon contains Methylcobalamin which is an essential water soluble vitamin B also known as vitamin B12. Vitamin B12 is required for nuclear-protein and myelin synthesis, cell reproduction, normal growth, and normal erythropoiesis. Vitamin B12 is converted to coenzyme B12, which is essential for the conversion of methylmalonate to succinate, and the synthesis of methionine from homocysteine. Vitamin B12 is involved in maintaining sulfhydryl groups in the reduced form required by enzymes involved in fat and carbohydrate metabolism, and protein synthesis. Vitamin B12 is involved in folate synthesis and a deficiency of methylcobalamin results in a functional folate deficiency. Vitamin B12 is required as part of the remethylation of homocysteine to methionine. Elevated levels of homocysteine has been linked to the increase risk of endothelial cell damage, impaired endothelial-dependent vasodilation due to reduced nitric oxide activity, increased oxidation and arterial deposition of low-density lipoproteins (LDL), increased platelet adhesiveness, and activation of the clotting cascade. Vitamin B12 supplements have a small additive effect to folic acid in lowering fasting homocysteine levels, but probably only in people with vitamin B12 deficiency. Elevated homocysteine concentrations are possibly associated with other conditions such as decreased cognitive function, impaired memory, Alzheimer's disease, and vascular dementia. The methylcobalamin form of vitamin B12 might also influence melatonin levels. Methylcobalamin seems to improve alertness and reduce sleep time in humans with normal sleep patterns, possibly due to effects on melatonin.
Pharmacokinetics: Vitamin B12 is absorbed via an active transport mechanism in the terminal ileum. This requires the glycoprotein, intrinsic factor, which is produced by the stomach. At normal gastric pH, vitamin B12 is cleaved from proteins in food. It then binds to intrinsic factor and is absorbed by ideal transport. Absorption may be reduced by increased gastric pH such as atrophic gastritis, use of acid-suppressing drugs, or partial gastrectomy. The half-life of vitamin B12 is 6 hours and is secreted mainly via the bile.
Methydon tablets are indicated for peripheral neuropathies and megaloblastic anemia caused by vitamin B12 deficiency.
Dosage/Direction for Use
Dosage: The dosage for clinical effect is 1500-6000 mcg per day. No significant therapeutic advantage appears to occur from dosages exceeding this maximum dose. Methylcobalamin has been administered orally, intramuscularly, and intravenously; however, positive clinical results have been reported irrespective of the method of administration. It is not clear whether any therapeutic advantage is gained from the non-oral methods of administration.
Method of administration: For oral use.
Treatment should be symptomatic and supportive.
In the case of accidental overdose of the product, contact the nearest hospital or poison control centre.
Hypersensitivity to the active substance or to any of the excipients.
Special Precautions
Caution should be exercised in patients with history of liver disease, any allergy, during pregnancy and breastfeeding.
Effects on Ability to Drive and Use Machines: There are no data about unfavorable influence on the active attention, reflexes and motor activity.
Use In Pregnancy & Lactation
Vitamin B12 is likely safe for pregnant or breast-feeding women when taken by mouth in the amounts recommended. The recommended amount for pregnant women is 2.6 mcg per day. Breast-feeding women should take no more than 2.8 mcg per day. Don't take larger amounts. The safety of larger amounts is unknown.
Adverse Reactions
In some people, vitamin B12 might cause diarrhea, blood clots, itching, serious allergic reactions, and other side effects.
Vitamin B12 also appears to be safe when used on the skin for psoriasis. Mild itching has been reported in one person who used a specific avocado oil plus vitamin B12 cream for psoriasis.
Irritability, Insomnia, Sore muscles, Achy joints, Acne, Rash, Severe anxiety, Palpitations, Nausea, Headaches, Migraines.
Adverse Drug Reactions: Inform doctors about unexpected reactions after using drugs.
Drug Interactions
Chloramphenicol: Limited case reports suggest that chloramphenicol can delay or interrupt the reticulocyte response to supplemental Vitamin B12 in some patients. Monitor blood levels carefully if the combination cannot be avoided.
Absorption: The following medicines can reduce the absorption of Vitamin B12: aminosalicylic acid, antibiotics, colchicine, cholestyramine, H2 blockers, metformin, neomycin, nitrous oxide, oral contraceptives, phenytoin, phenobarbital, primidone, proton pump inhibitor, zidovudine.
Store below 30°C. Protect from light & moisture.
Shelf-Life: 24 months.
MIMS Class
Vitamins & Minerals (Pre & Post Natal) / Antianemics
ATC Classification
B03BA05 - mecobalamin ; Belongs to the class of vitamin B12 (cyanocobalamin and analogues). Used in the treatment of anemia.
FC tab 500 mcg (brown coloured, standard biconvex, round shaped, plain on both sides) x 3 x 10's, 10 x 10's.
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