AMCOBAL Injection 500 msg I.M/I.V

AMCOBAL Injection	500 msg I.M/I.V

AMCOBAL Injection 500 msg I.M/I.V

NERVON (Mecobalamin) is a B12 containing coenzyme with an active methyl base. It plays an important role in red blood cell formation, methylation reaction, brain and nervous system functions and immune sytem functions. Chemically, mecobalamin is described as α (5,6- Dimethylbenzimidazolyl)-Co-methyl-cobamide. The molecular formula is C63H91CoN13O14P.

COMPOSITION
AMCOBAL I.M./I.V. Injection 500mcg
Each 1 mL ampoule contains:
Mecobalamin………………………………………… 500mcg

CLINICAL PHARMACOLOGY
Mechanism of Action
1. Mecobalamin is the one and only homologue of Vitamin B12 found in the brain that participates in
transmethylation. Mecobalamin is well transported to nerve cell organelles than cyanocobalamin and plays the role of coenzyme in the synthesis of methionine from homocysteine. It is also involved in the synthesis of thymidine from deoxyuridine thus promoting nucleic acid protein synthesis.

2. Mecobalamin normalizes axonal transport of skeletal protein in sciatic nerve cells. It exhibits
neuropathologically and electrophysiologically inhibitory effects on nerve degeneration in neuropathies induced by drugs such as adriamycin, acrylamide and vincristine.

3. Mecobalamin promotes the synthesis of lecithin, the main constituent of medullary sheath lipid, by
increasing methionine synthetase activity, thus promoting myelination (phospholipid synthesis).

4. Mecobalamin restores end-plate potential early induction by increasing nerve fiber excitability in the
crushed sciatic nerve. In addition, mecobalamin normalizes diminished brain tissue levels of acetylcholine.

5. Mecobalamin promotes nucleic acid synthesis in the bone marrow and promotes the maturation and
division of erythroblasts thereby improving anemia, thus increasing erythrocyte production.

PHARMACOKINETICS
Vitamin B12 substances bind to intrinsic factor, a glycoprotein secreted by the gastric mucosa and are then actively absorbed from the gastrointestinal tract. Vitamin B12 is extensively bound (80%) to specific plasma proteins called transcobalamins; transcobalamin II appears to be involved in the rapid transport of the cobalamins to tissues. After oral administration of single doses of 120mcg or 1500mcg of mecobalamin dose dependent peak plasma concentrations were reached in 3 hours in both cases. After a single I.M or I.V dose of 500mcg, the time required for the serum total vitamin B12 level to reach a peak (tmax) was 0.9 + 0.1 hours after I.M and immediately to 3 min after I.V administration. The area under the blood concentration-time curve (AUC) at 144 hours after administration was 204.1 + 12.9hr.ng/mL after I.M administration and 358.6 + 34.4hr.ng/mL after I.V administration. The increment in peak serum total vitamin B12 level (Cmax) was 22.4 +1.1ng/mL after I.M administration and 85.0 + 8.9ng/mL after I.V administration. Vitamin B12 is stored in the liver (50%), excreted in the bile and undergoes extensive enterohepatic recycling. Some of the B12 secreted in the bile is excreted in the feces while the other part is excreted in the urine (40- 80%), most of it in the first 8 hours. Vitamin B12 diffuses across the placenta and also appears in breast milk.

THERAPEUTIC INDICATIONS
AMCOBAL (Mecobalamin) is indicated for the treatment of:
1. Peripheral neuropathies.
2. Megaloblastic anemia caused by vitamin B12 deficiency

DOSAGE AND ADMINISTRATION
AMCOBAL (Mecobalamin) tablets can be taken with or without food. The dosage may be adjusted depending on patient’s age and symptoms.

Peripheral neuropathies
Injection: The usual dosage for adults is 1 ampoule (500mcg of mecobalamin) a day administered intramuscularly or intravenously three times a week.

MEGALOBLASTIC ANEMIA
The usual dosage for adults is 1 ampoule (500mcg of mecobalamin) a day administered intramuscularly or intravenously three times a week. After approximately 2 months of medication, the dose should be reduced to a single administration of NERVON (Mecobalamin) ampoule at 1 to 3 months intervals for maintenance therapy.

CONTRAINDICATION
Mecobalamin is contraindicated in patients who are hypersensitive to this drug or any component of this
product or other B12 containing products.

ADVERSE REACTIONS

Generally mecobalamin is well tolerated. However a few side effects like GI discomfort (including anorexia, nausea or diarrhoea and rash may be seen.

PRECAUTIONS
Mecobalamin injection should not be used over a period of months if there is lack of satisfactory clinical response in patients with magaloblastic anemia probably due to vitamin B12 deficiency or with peripheral neuropathies.

PREGNANCY AND LACTATION
Mecobalamin is not recommended in pregnant and lactating women.

STORAGE
Store below 30°C.
Protect from light and moisture.
Store in cool and dry place.

NERVON (Mecobalamin) injection is stored in light protective packs (LPP). Light protective packs ensures
quality during storage. This pack should be opened only prior to use. If ampoules are kept out of the light protective packs (LPP) the drug will decompose upon exposure to light.
Keep out of the reach of children.

PRESENTATION
AMCOBAL (Mecobalamin) 500mcg I.M./I.V. injection is available in blister pack of 10x1mL ampoules.