Cyanocobalamin side effects
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Cyanocobalamin Side Effects: An Overview
Introduction to Cyanocobalamin
Cyanocobalamin, a synthetic form of Vitamin B12, is essential for maintaining healthy nerves and blood cells and plays a crucial role in DNA synthesis. It is commonly used to treat Vitamin B12 deficiency, which can lead to conditions such as megaloblastic anemia, characterized by fatigue and weakness1. However, despite its benefits, cyanocobalamin can have side effects, some of which are rare but potentially serious.
Anaphylactic Reactions to Cyanocobalamin
Rare but Serious Hypersensitivity
Anaphylactic reactions to cyanocobalamin, though uncommon, are serious and potentially life-threatening. These reactions can occur due to an immunoglobulin E (IgE)-mediated response or sensitization to the Vitamin B12 molecule itself. Several case reports have documented instances of severe anaphylactic reactions following intramuscular injections of cyanocobalamin1 3 4. For example, a 25-year-old female patient with pulmonary tuberculosis experienced an anaphylactoid reaction after receiving a cyanocobalamin injection1. Similarly, a 55-year-old woman developed an anaphylactic reaction after her second dose of intramuscular cyanocobalamin3. These cases highlight the need for healthcare providers to be vigilant when administering cyanocobalamin, especially via the parenteral route.
Toxicity from High Doses
Symptoms of Overdose
Excessive intake of cyanocobalamin can lead to toxicity, although such cases are rare. A young woman treated with multiple daily doses of 1 mg of cyanocobalamin for severe pernicious anemia developed symptoms such as acne, palpitations, anxiety, akathisia, facial ruddiness, headache, and insomnia after a total dose of 12 mg. These symptoms subsided two weeks after discontinuing the drug, indicating that while cyanocobalamin toxicity is unusual, it is possible and should be monitored2.
Impact on Renal Function
Potential Harm in Patients with Impaired Renal Function
Cyanocobalamin can accelerate the decline in renal function and increase the risk of cardiovascular events in patients with impaired renal function. Studies have shown that high-dose cyanocobalamin does not benefit patients with impaired renal function for stroke prevention and may even be harmful. Conversely, patients with normal renal function may benefit from B vitamin therapy, suggesting that the form of Vitamin B12 used in treatment should be carefully considered7.
Cytotoxicity in Cell Studies
Antagonistic Effects and Cell Death
Research has shown that cyanocobalamin [c-lactam], a derivative of cobalamin, can antagonize Vitamin B12 and cause cytotoxicity in HL60 cells. This cytotoxic effect is reversible with additional Vitamin B12 and can be completely protected against by methionine. These findings suggest that cyanocobalamin [c-lactam] impairs critical cellular processes, leading to cell death from methionine deficiency9.
Conclusion
While cyanocobalamin is an effective treatment for Vitamin B12 deficiency, it is not without risks. Anaphylactic reactions, toxicity from high doses, potential harm to renal function, and cytotoxic effects in cell studies underscore the importance of careful administration and monitoring. Healthcare providers should be aware of these potential side effects to ensure the safe use of cyanocobalamin in their patients.
Sources and full results
Most relevant research papers on this topic
Cyanocobalamin-induced anaphylactic reaction
Anaphylactic reactions to Vitamin B12 are a rare but serious side effect, and should be closely monitored during patient administration, especially when using the parenteral route.
Case ReportToxicity induced by multiple high doses of vitamin B12 during pernicious anemia treatment: a case report
Multiple high doses of vitamin B12 during pernicious anemia treatment can cause unexpected and unusual side effects, such as acne, palpitations, anxiety, and insomnia.
Case ReportAnaphylactic Reaction to Cyanocobalamin: A Case Report
Anaphylactic reaction is a rare but potentially life-threatening side effect of intramuscular cyanocobalamin, highlighting the need for vigilant healthcare providers when administering this treatment to vitamin B12 deficient patients.
Case ReportAnaphylactic reaction after intramuscular injection of cyanocobalamin (vitamin B12): a case report.
Anaphylactic reaction to vitamin B12 is a rare but serious side effect, especially when administered via the parenteral route.
Case ReportStudy of the protective effects of cyanocobalamin on methotrexate induced nephrotoxicity in rats.
Cyanocobalamin has a nephroprotective action against methotrexate-induced renal damage in rats, potentially offering a protective effect through antioxidant action.
RCT
Animal Study
Rigorous JournalA controlled trial of cyanocobalamin (vitamin B12) in the treatment of winter seasonal affective disorder.
Cyanocobalamin does not appear to be an effective short-term treatment for depression in winter seasonal affective disorder patients.
RCTB vitamins in stroke prevention: time to reconsider
B vitamin therapy may reduce stroke risk in individuals with normal renal function, but not in those with impaired renal function.
Meta-Analysis
Highly CitedA randomized controlled trial examining the effects of treatment with propylene glycol and injectable cyanocobalamin on naturally occurring disease, milk production, and reproductive outcomes of dairy cows diagnosed with concurrent hyperketonemia and hypoglycemia.
Propylene glycol and cyanocobalamin treatment improves health, milk production, and reproductive outcomes in dairy cows with hyperketonemia, hypoglycemia, or concurrent hyperketonemia and hypoglycemia.
RCTAnimal StudyRigorous JournalCyanocobalamin [c-lactam] inhibits vitamin B12 and causes cytotoxicity in HL60 cells: methionine protects cells completely.
Cyanocobalamin [c-lactam] antagonizes vitamin B12 in vitro and causes cell death from methionine deficiency, but methionine completely protects cells from this effect.
In Vitro StudyParenteral Cyanocobalamin Induced Arthralgia: A Case Report
Cyanocobalamin injections can occasionally cause rare adverse events, such as arthralgia, and methyl cobalamin can effectively manage joint pain.
Case Report