Drug Ingredient Information
METHYLCOBALAMIN-2500MCG/ML
METHYLCOBALAMIN
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patients
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| Drug Information |
Vitamin B12, is used to treat vitamin B12 deficiency, cyanide poisoning, and hereditary deficiency of transcobalamin II.[3] It is also given as part of the schilling test for detecting pernicious anemia.[3]
For cyanide poisoning, large amount may be given intravenously, and sometimes in combination with sodium thiosulfate.[4] The mechanism of action is straightforward: the hydroxycobalamin hydroxide ligand is displaced by the toxic cyanide ion, and the resulting harmless B12 complex is excreted in urine. In the United States, the Food and Drug Administration approved (in 2006) the use of hydroxocobalamin for acute treatment of cyanide poisoning.[5]
High vitamin B12 level in elderly individuals may protect against brain atrophy or shrinkage, associated with Alzheimer's disease and impaired cognitive function.[6]
High-dose administration of Vitamin B12 has been additionally validated to stimulate the activity of the body's TH1 suppressor T-Cells, which then down-regulates the over-production of the allagen antibody 1gE in allergic individuals |
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no data available |
| Before Consuming
the Medicine
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| Avoid Drug |
Vitamin B12 supplements in theory should be avoided in people sensitive or allergic to cobalamin, cobalt, or any other product ingredients. However, direct allergy to a vitamin or nutrient is extremely rare, and if reported, other causes should be sought. |
| Drug Special Care |
no data available |
| Drug Drug Interactions |
Aminosalicylic acid (para-aminosalicylic acid, PAS, Paser): Aminosalicylic acid can reduce oral vitamin B12 absorption, possibly by as much as 55%, as part of a general malabsorption syndrome. Megaloblastic changes, and occasional cases of symptomatic anemia have occurred, usually after doses of 8 to 12 g/day for several months. Vitamin B12 levels should be monitored in people taking aminosalicylic acid for more than one month.
Antibiotics: An increased bacterial load can bind significant amounts of vitamin B12 in the gut, preventing its absorption. In people with bacterial overgrowth of the small bowel, antibiotics such as metronidazole (Flagyl) can actually improve vitamin B12 status. The effects of most antibiotics on gastrointestinal bacteria are unlikely to have clinically significant effects on vitamin B12 levels.
Hormonal contraception: The data regarding the effects of oral contraceptives on vitamin B12serum levels are conflicting. Some studies have found reduced serum levels in oral contraceptive users, but others have found no effect despite use of oral contraceptives for up to 6 months. When oral contraceptive use is stopped, normalization of vitamin B12 levels usually occurs. Lower vitamin B12serum levels seen with oral contraceptives probably are not clinically significant.
Chloramphenicol (Chloromycetin): Limited case reports suggest that chloramphenicol can delay or interrupt the reticulocyte response to supplemental vitamin B12 in some patients. Blood counts should be monitored closely if this combination cannot be avoided.
Cobalt irradiation: Cobalt irradiation of the small bowel can decrease gastrointestinal (GI) absorption of vitamin B12.
Colchicine: Colchicine in doses of 1.9 to 3.9 mg/day can disrupt normal intestinal mucosal function, leading to malabsorption of several nutrients, including vitamin B12. Lower doses do not seem to have a significant effect on vitamin B12 absorption after 3 years of colchicine therapy. The significance of this interaction is unclear. Vitamin B12 levels should be monitored in people taking large doses of colchicine for prolonged periods.
Colestipol (Colestid), cholestyramine (Questran): These resins used for sequestering bile acids to decrease cholesterol, can decrease gastrointestinal (GI) absorption of vitamin B12. It is unlikely this interaction will deplete body stores of vitamin B12 unless there are other factors contributing to deficiency. In a group of children treated with cholestyramine for up to 2.5 years, there was not any change in serum vitamin B12 levels. Routine supplements are not necessary.
H2-receptor antagonists: include cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), and ranitidine (Zantac). Reduced secretion of gastric acid and pepsin produced by H2 blockers can reduce absorption of protein-bound (dietary) vitamin B12, but not of supplemental vitamin B12. Gastric acid is needed to release vitamin B12 from protein for absorption. Clinically significant vitamin B12 deficiency and megaloblastic anemia are unlikely, unless H2 blocker therapy is prolonged (2 years or more), or the person's diet is poor. It is also more likely if the person is rendered achlorhydric(with complete absence of gastric acid secretion), which occurs more frequently with proton pump inhibitors than H2 blockers. Vitamin B12 levels should be monitored in people taking high doses of H2 blockers for prolonged periods.
Metformin (Glucophage): Metformin may reduce serum folic acid and vitamin B12 levels. These changes can lead to hyperhomocysteinemia, adding to the risk of cardiovascular disease in people with diabetes.[citation needed] There are also rare reports of megaloblastic anemia in people who have taken metformin for five years or more. Reduced serum levels of vitamin B12 occur in up to 30% of people taking metformin chronically.[20][21] However, clinically significant deficiency is not likely to develop if dietary intake of vitamin B12 is adequate. Deficiency can be corrected with vitamin B12 supplements even if metformin is continued. The metformin-induced malabsorption of vitamin B12 is reversible by oral calcium supplementation.[22] The general clinical significance of metformin upon B12 levels is as yet unknown.[23]
Neomycin: Absorption of vitamin B12 can be reduced by neomycin, but prolonged use of large doses is needed to induce pernicious anemia. Supplements are not usually needed with normal doses.
Nicotine: Nicotine can reduce serum vitamin B12 levels. The need for vitamin B12 supplementation in smokers has not been adequately studied.
Nitrous oxide: Nitrous oxide inactivates the cobalamin form of vitamin B12 by oxidation. Symptoms of vitamin B12 deficiency, including sensory neuropathy, myelopathy, and encephalopathy, can occur within days or weeks of exposure to nitrous oxide anesthesia in people with subclinical vitamin B12 deficiency. Symptoms are treated with high doses of vitamin B12, but recovery can be slow and incomplete. People with normal vitamin B12 levels have sufficient vitamin B12 stores to make the effects of nitrous oxide insignificant, unless exposure is repeated and prolonged (such as recreational use). Vitamin B12 levels should be checked in people with risk factors for vitamin B12 deficiency prior to using nitrous oxide anesthesia. Chronic nitrous oxide B12 poisoning (usually from use of nitrous oxide as a recreational drug), however, may result in B12 functional deficiency even with normal measured blood levels of B12.[24]
Phenytoin (Dilantin), phenobarbital, primidone (Mysoline): These anticonvulsants have been associated with reduced vitamin B12 absorption, and reduced serum and cerebrospinal fluidlevels in some patients. This may contribute to the megaloblastic anemia, primarily caused by folate deficiency, associated with these drugs. It is also suggested that reduced vitamin B12 levels may contribute to the neuropsychiatric side effects of these drugs. Patients should be encouraged to maintain adequate dietary vitamin B12 intake. Folate and vitamin B12 status should be checked if symptoms of anemia develop.
Proton pump inhibitors (PPIs): The PPIs include omeprazole (Prilosec, Losec), lansoprazole(Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix, Pantoloc), and esomeprazole (Nexium). The reduced secretion of gastric acid and pepsin produced by PPIs can reduce absorption of protein-bound (dietary) vitamin B12, but not supplemental vitamin B12. Gastric acid is needed to release vitamin B12 from protein for absorption. Reduced vitamin B12 levels may be more common with PPIs than with H2-blockers, because they are more likely to produce achlorhydria (complete absence of gastric acid secretion). However, clinically significant vitamin B12 deficiency is unlikely, unless PPI therapy is prolonged (2 years or more) or dietary vitamin intake is low. Vitamin B12 levels should be monitored in people taking high doses of PPIs for prolonged periods.
Zidovudine (AZT, Combivir, Retrovir): Reduced serum vitamin B12 levels may occur when zidovudine therapy is started. This adds to other factors that cause low vitamin B12 levels in people with HIV, and might contribute to the hematological toxicity associated with zidovudine. However, the data suggest vitamin B12 supplements are not helpful for people taking zidovudine.[citation needed]
Folic acid: Folic acid, particularly in large doses, can mask vitamin B12 deficiency by completely correcting hematological abnormalities. In vitamin B12 deficiency, folic acid can produce complete resolution of the characteristic megaloblastic anemia, while allowing potentially irreversible neurological damage (from continued inactivity of methylmalonyl mutase) to progress. Thus, vitamin B12 status should be determined before folic acid is given as monotherapy.
Potassium: Potassium supplements can reduce absorption of vitamin B12 in some people. This effect has been reported with potassium chloride and, to a lesser extent, with potassium citrate. Potassium might contribute to vitamin B12 deficiency in some people with other risk factors, but routine supplements are not necessary. |
| Drug Pregnancy Interaction |
no data available |
| Drug Breast feeding Interaction |
no data available |
| Drug Machinery Interaction |
no data available |
| Drug More Information |
Alcohol (ethanol): Excessive alcohol intake lasting longer than two weeks can decrease vitamin B12 absorption from the gastrointestinal tract |
| How to take the
Medicine
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| Consumption Info |
no data available |
| Drug quanitty |
The dietary reference intake for an adult ranges from 2 to 3 µg per day.[9]
Vitamin B12 is believed to be safe when used orally in amounts that do not exceed the recommended dietary allowance (RDA). There have also been studies that showed no adverse consequences of doses above the RDA.[10] The RDA for vitamin B12 in pregnant women is 2.6 µg per day and 2.8 µg during lactation periods.[citation needed] There is insufficient reliable information available about the safety of consuming greater amounts of vitamin B12 during pregnancy.
The Vegan Society, the Vegetarian Resource Group, and the Physicians Committee for Responsible Medicine, among others, recommend that vegans either consistently eat foods fortified with B12 or take a daily or weekly B12 supplement.[11][12][13] Fortified breakfast cereals are a particularly valuable source of vitamin B12 for vegetarians and vegans. In addition, adults age 51 and older are recommended to consume B12 fortified food or supplements to meet the RDA, because they are a population at an increased risk of deficiency. |
| Drug Dose |
no data available |
| Excess Drug Consumption |
no data available |
| Forgot Drug Consumption |
contact your doctor |
| Stop Drug Consumption |
do not stop the medicine untill adviced by your doctor |
| Possible Side
Effects
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| General Information |
no data available |
| Common Drug Side Effects |
Vitamin B12 has extremely low toxicity and even taking it in enormous doses appears not to be harmful to healthy individuals.[17][18]
Hematologic: Peripheral vascular thrombosis has been reported. Treatment of vitamin B12 deficiency can unmask polycythemia vera, which is characterized by an increase in blood volume and the number of red blood cells. The correction of megaloblastic anemia with vitamin B12 can result in fatal hypokalemia and gout in susceptible individuals, and it can obscure folate deficiency in megaloblastic anemia. Caution is warranted.
Leber's disease: Vitamin B12 in the form of cyanocobalamin is contraindicated in early Leber's disease, which is hereditary optic nerve atrophy. Cyanocobalamin can cause severe and swift optic atrophy, but other forms of vitamin B12 are available. However, the sources of this statement are not clear, while an opposing view[19] concludes: "The clinical picture of optic neuropathy associated with vitamin B12 deficiency shows similarity to that of Leber's disease optic neuropathy. Both involve the nerve fibres of the papillomacular bundle. The present case reports suggest that optic neuropathy in patients carrying a primary LHON mtDNA mutation may be precipitated by vitamin B12 deficiency. Therefore, known carriers should take care to have an adequate dietary intake of vitamin B12 and malabsorption syndromes like those occurring in familial pernicious anaemia or after gastric surgery should be excluded." |
| Rare Drug Side Effects |
no data available |
| Very Rare Drug Side Effects |
no data available |
| Drug Side Effects Symptoms |
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| How to Store the
Medicine
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| How to Store the Medicine |
Keep container in a cool, well-ventilated area. keep at 2-8c |
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