|
Indications and Dosage
Intramuscular, Intravenous
Megaloblastic anaemia caused by vitamin B12 deficiency Adult: Initially, 500 mcg via IV or IM inj 3 times weekly for 2 months. Maintenance dose: 500 mcg via IV or IM inj every 1-3 months. Intramuscular, Intravenous Peripheral neuropathy Adult: 500 mcg via IV or IM inj 3 times weekly, may adjust dose depending on patient’s age and severity of symptoms. Oral Peripheral neuropathy Adult: 500 mcg tid, may adjust dose depending on patient’s age and severity of symptoms.
|
|
Administration
May be taken with or without food.
|
|
Special Precautions
Pregnancy and lactation. Not recommended for prolonged use and higher doses in patients with regular exposure to Hg or its compounds.
|
|
Adverse Reactions
Significant: Anaphylactic reactions (inj) (e.g. dyspnoea, hypotension); hypokalaemia, thrombocytosis.
Gastrointestinal disorders: Nausea, vomiting, diarrhoea. General disorders and administration site conditions: Pain or induration at inj site; feeling hot, diaphoresis. Metabolism and nutrition disorders: Loss of appetite. Nervous system disorders: Headache. Skin and subcutaneous tissue disorders: Rash. Potentially Fatal: Anaphylactic shock (inj). |
|
Monitoring Parameters
Megaloblastic anaemia: Monitor CBC, platelet count, reticulocyte count, folate, Fe; vitamin B12 level, serum K.
|
|
Drug Interactions
Reduced absorption with colchicine, metformin, neomycin, para-aminosalicyclic acid, chloramphenicol, K chloride, histamine H2 antagonists, and omeprazole. Decreased enterohepatic reabsorption with colestyramine and colestipol. Decreased serum concentration with oral contraceptives.
|
|
Lab Interference
Mecobalamin blood assays may be invalidated by methotrexate, pyrimethamine, and most antibiotics.
|
|
Action
Description:
Mechanism of Action: Mecobalamin, a water-soluble vitamin, is a biologically active form of vitamin B12. It acts as a coenzyme in the synthesis of methionine from homocysteine. It promotes nucleic acid and protein synthesis in nerve cells, promotes axonal transport and regeneration. Additionally, it enhances nerve fibre excitability, promotes lecithin synthesis by increasing myelination, and promotes maturation and division of erythroblasts. Synonym(s): Methylcobalamin. Pharmacokinetics: Absorption: Actively absorbed from the gastrointestinal tract. Time to peak plasma concentration: 3-4 hours (oral); approx 1 hour (IM). Distribution: Crosses the placenta, enters breast milk. Extensively bound to transcobalamins. Metabolism: Undergoes extensive enterohepatic recycling. Excretion: Via urine. Elimination half-life: 12.5 hours (oral); 27-29 hours (inj). |
|
Storage
Tab/cap: Store below 30°C. Protect from light and moisture. Inj: Store below 30°C. Do not freeze. Protect from light. Storage recommendations may vary among countries or individual products (refer to specific product guidelines).
|
|
ATC Classification
B03BA05 - mecobalamin ; Belongs to the class of vitamin B12 (cyanocobalamin and analogues). Used in the treatment of anemia.
|
|
References
Anon. Mecobalamin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 04/08/2023. Buckingham R (ed). Vitamin B12 Substances. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 04/08/2023. Mebaal-500/Mebaal-1500 (Mega Lifesciences). MIMS Philippines. http://www.mims.com/philippines. Accessed 04/08/2023. Meconeuro (PT Novell). MIMS Philippines. http://www.mims.com/philippines. Accessed 04/08/2023. Methycobal (Eisai). MIMS Malaysia. http://www.mims.com/malaysia. Accessed 04/08/2023.
|
Sign Out
