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Hydroxocobalamin injection

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Hydroxocobalamin injection

Hydroxocobalamin injection_EN

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Hydroxocobalamin injection

Property Description
Active ingredient Hydroxocobalamin (Vitamin B12)
Form Sterile solution for injection (Parenteral)
Pharmacological class B Vitamin, Anti-Anemic Preparation, Cobalamin
Common use Correction/prevention of Vitamin B12 deficiency
Origin Synthetic form

What Type of Medicine is Hydroxocobalamin Injection?

Hydroxocobalamin injection is a sterile solution containing the active ingredient Hydroxocobalamin, which is a vital form of Vitamin B12. This medication is classified pharmacologically as a water-soluble vitamin and a key component within the group of anti-anemic preparations. Cobalamin is essential for fundamental metabolic processes in the body. As a prescription-only, single-ingredient product, it is delivered as a high-concentration parenteral preparation, which is clinically recognized for providing effective systemic delivery of the nutrient.

Composition and Origin: Is Hydroxocobalamin Natural or Synthetic?

The medication is prepared as an aqueous solution, where the Hydroxocobalamin active ingredient is dissolved in water for injection. Although this substance is chemically related to the vitamin found in food, the pharmaceutical substance utilized is a highly purified synthetic form. This injectable type is often preferred over the analogue cyanocobalamin because it exhibits a higher retention rate within the body, remaining available longer for use by cells. This higher retention rate is beneficial for patients needing sustained levels of the vitamin, such as those diagnosed with pernicious anemia.

General Purpose: Why is Hydroxocobalamin Given as an Injection?

The general purpose of the injection is to correct or prevent deficiencies of Vitamin B12 in the body. The compound acts as a precursor to active cofactors essential for the health of two systems: it supports the healthy formation of red blood cells and the proper maintenance of nerve function. This type of injectable delivery is typically used in scenarios involving malabsorption syndromes, where oral supplementation is insufficient. By ensuring a reliable supply of this essential B vitamin, the injection helps to relieve the generalized fatigue, weakness, and neurological issues that result when the body's reserve of this critical nutrient is depleted.

What side effects are possible with Hydroxocobalamin injection?

Possible Side Effects and Safety Information

The safety profile of Hydroxocobalamin injection, as documented in official regulatory labeling, includes adverse reactions categorized across several body systems. The frequency of many effects is officially listed as Not Known, meaning it cannot be reliably estimated from available data, although some reactions like acneiform and bullous skin eruptions are documented as Rare.

System-Organ Classification

Side effects are classified by the affected system, including Immune system disorders (e.g., severe hypersensitivity, anaphylaxis), Gastrointestinal disorders (e.g., nausea, mild transient diarrhea), Skin and subcutaneous tissue disorders (e.g., rash, itching, injection site reactions), and Nervous system disorders (e.g., headache, tremor).

Serious Adverse Reactions and Safety Constraints

Serious adverse reactions documented in regulatory sources include anaphylaxis and cardiac arrhythmias that have been reported secondary to a drop in potassium levels (hypokalaemia), particularly during the initial phase of treatment for severe deficiency.

The medication is contraindicated in individuals with a known hypersensitivity to the active substance, excipients, or cobalt. Time-related safety patterns include the potential for reactive thrombocytosis (increased platelet count) in the first weeks of use.

Important Safety Notes

Official labels note that the medication can cause chromaturia (red coloring of the urine), which may interfere with the determination of certain laboratory tests. Indiscriminate use is restricted as it may mask the diagnosis of folate deficiency.

Overdose and Emergency Response

Overdose and When to Seek Help

The regulatory profile for Hydroxocobalamin injection indicates that for the vitamin deficiency treatment dose, the substance exhibits low acute toxicity and no symptoms of overdosing are established in official labeling. The overdose profile is instead defined by systemic effects observed only at massive intravenous administration, which is substantially higher than the dose used for correction of Vitamin B12 deficiency.

Documented Manifestations and Serious Outcomes

Manifestations following high-dose exposure include a transient, generally asymptomatic increase in blood pressure and the expected red colouration of the skin and urine (chromaturia) that may persist for several days. More serious outcomes reported in official labeling include acute renal failure with acute tubular necrosis, renal impairment, and the formation of urine calcium oxalate crystals. A critical risk documented is the potential for anaphylaxis and other severe hypersensitivity reactions.

Emergency Actions and Monitoring

Since no specific antidote is known, overdose management is restricted to symptomatic and supportive treatment. Regulators state that immediate medical attention must be sought for signs of severe allergic reaction, such as swelling of the face, tongue, or difficulty breathing. Furthermore, following high exposure, monitoring of renal function should be performed for up to seven days, and the expert advice of a regional poison control center may be obtained.

Therapeutic Uses of Hydroxocobalamin injection

Main Uses of Hydroxocobalamin Injection

Hydroxocobalamin is a synthetic form of vitamin B12, an essential nutrient required for the proper functioning of the nervous system, the formation of red blood cells, and DNA synthesis. In injectable form, it is primarily used to treat conditions where oral supplementation is insufficient or ineffective.

Vitamin B12 Deficiency

Hydroxocobalamin is used to treat and prevent vitamin B12 deficiency. This deficiency can occur due to various factors, including:

  • Dietary insufficiency: Especially in individuals following strict vegan or vegetarian diets without adequate supplementation.
  • Malabsorption: Conditions that interfere with the body's ability to absorb vitamin B12 from food, such as Crohn's disease, celiac disease, or certain types of gastric surgery.
  • Pernicious anemia: An autoimmune condition where the stomach fails to produce intrinsic factor, a protein necessary for B12 absorption.

Megaloblastic Anemia

When vitamin B12 levels are critically low, the body may produce abnormally large, immature red blood cells that cannot function correctly. This is known as megaloblastic anemia. Hydroxocobalamin helps restore healthy red blood cell production, improving the blood's oxygen-carrying capacity.

Neurological Health

Vitamin B12 is vital for maintaining the myelin sheath, the protective covering of nerves. Hydroxocobalamin is used to treat neurological complications associated with deficiency, such as peripheral neuropathy, which may manifest as tingling, numbness, or weakness in the limbs.

Cyanide Poisoning

In acute emergency settings, hydroxocobalamin is utilized as an antidote for cyanide poisoning. It works by binding to cyanide ions to form cyanocobalamin, a non-toxic substance that is then safely excreted from the body through the kidneys.

Benefits of Injectable Hydroxocobalamin

Efficient Absorption

By delivering the vitamin directly into the muscle or under the skin, hydroxocobalamin bypasses the digestive system. This ensures that the full dose is available to the body, making it particularly beneficial for individuals with severe malabsorption issues.

Long-Lasting Action

Hydroxocobalamin is retained in the body longer than other forms of vitamin B12, such as cyanocobalamin. This often allows for longer intervals between injections while maintaining stable vitamin levels in the bloodstream.

Rapid Symptom Relief

For those experiencing severe symptoms of deficiency, such as extreme fatigue or cognitive difficulties, the injectable form can provide faster restoration of B12 levels compared to oral supplements, potentially leading to a more rapid improvement in clinical symptoms.

Regulatory References

  1. FDA-approved labeling via DailyMed

Eligibility and Restrictions for Use

Eligibility: Who Can and Cannot Use Hydroxocobalamin Injection

The eligibility for Hydroxocobalamin injection is defined by official regulatory labeling, specifying populations for whom use is established, restricted, or strictly contraindicated.

Populations Excluded from Use

Hydroxocobalamin injection is strictly contraindicated in patients with a known history of hypersensitivity to the active substance, Hydroxocobalamin, or to related compounds like cyanocobalamin or cobalt. Use is generally not recommended in patients diagnosed with Leber's disease or tobacco amblyopia due to the risk of severe optic nerve damage, as specified in regulatory documents.

Established and Conditional Use

Population Group Eligibility Status (Regulatory Basis)
Adults & Pediatrics Established Use for the treatment of confirmed Vitamin B12 deficiency.
Pregnancy Conditional Use; permitted only when clearly necessary for treating B12 deficiency.
Lactation Generally permitted for deficiency treatment; high-dose use for cyanide poisoning is not recommended.
Renal Impairment Caution recommended; monitoring of renal function may be necessary, particularly with high-dose use.

Eligibility is established for both adults and pediatric patients requiring parenteral treatment for confirmed Vitamin B12 deficiency. For patients who are pregnant, regulatory documents allow use only if the treatment is clinically necessary. Use for patients with renal impairment requires caution and monitoring, as noted in the official labeling.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Hydroxocobalamin injection documents several interaction patterns categorized by their effect on therapeutic response and Vitamin B12 status.

Pharmacodynamic and Status-Reducing Interactions

A pharmacodynamic interaction is documented with Chloramphenicol, which may antagonize the hematopoietic response to Vitamin B12 therapy in patients with pernicious anemia. Furthermore, Folic Acid administered in doses greater than 0.1 mg per day may produce hematologic remission but will not prevent neurological damage, potentially masking the true diagnosis of B12 deficiency.

Interactions that reduce B12 status include co-administration of Colchicine and Para-aminosalicylic acid, which are documented to produce malabsorption of Vitamin B12. Use of Oral Contraceptives may also lead to lowered serum concentrations of hydroxocobalamin, and heavy alcohol intake for longer than two weeks is associated with reduced B12 levels.

Procedural and Diagnostic Interference

For the injectable form, timing-based procedural restrictions apply: the solution is not physically compatible with certain alkaline solutions and drugs, requiring that these agents must not be administered simultaneously through the same IV line. Additionally, antimetabolites and most antibiotics are known to invalidate Vitamin B12 assays performed using microbiological techniques, leading to diagnostic interference. Regulatory studies supporting these interactions were primarily performed in adults, indicating a lack of specific interaction data for the paediatric population.

Mechanism of Action

The core mechanism of Hydroxocobalamin is its function as a precursor to the active coenzyme Methylcobalamin, which is necessary for the enzyme methionine synthase ( MS). Activating MS is essential for regenerating the usable form of folate required for the synthesis of DNA components. This biochemical correction supports the restoration of effective erythropoiesis (red blood cell production) and normalizes erythroblast maturation. A second, distinct mechanism involves the conversion of Hydroxocobalamin into 5-deoxyadenosylcobalamin, the required cofactor for the enzyme methylmalonyl-CoA mutase ( MCM). Activating MCM is critical for correct lipid metabolism, preventing the accumulation of toxic compounds like methylmalonic acid. This metabolic correction is required for maintaining the structural integrity of the myelin sheath and supports the function of nerve cells. The capacity of the mechanism to correct the hematological defect is functionally dependent on the availability of folate, as the B12-dependent reaction requires this substrate to proceed. The mechanism is responsible for mitigating metabolic dysfunction in nerve tissues; however, its ability to restore function is physiologically constrained when severe structural damage to nerve fibers has progressed.

Dosage and Administration Information

How to Use Hydroxocobalamin Injection: Official Administration Guidelines

Hydroxocobalamin injection is administered under two distinct protocols, dictated by the specific clinical necessity, which determines the required route, dose, and frequency.

Administration Scope

Usage Context Administration Route Standard Dosing Pattern Frequency and Duration
Vitamin B12 Deficiency Intramuscular (IM) injection Initial: 30 to 1000 mu g Initial: Daily or alternate days for 1-2 weeks
Maintenance: 100 to 1000 mu g Maintenance: Every 2 to 3 months, often lifelong
Acute Cyanide Poisoning Intravenous (IV) infusion or Intraosseous (IO) Initial: 5 grams (g) Single emergency use; second dose may be administered

Procedural and Population Rules

For Vitamin B12 Deficiency, the treatment involves an initial intensive course followed by an intermittent, long-term maintenance schedule, which is administered via IM injection. Pediatric dosage schemes for this indication may align with adult regimens.

For the acute cyanide poisoning protocol, the drug is supplied as a lyophilized powder and requires specialized preparation. The 5 g dose must be reconstituted with 200 mL of a compatible diluent, such as 0.9% Sodium Chloride, by inverting or rocking the vial for at least 60 seconds, not shaking it. This high-dose infusion is delivered through a dedicated intravenous line over a regulated time period (e.g., 15 minutes for the initial dose). The maximum total dose is 10 g. Pediatric dosing for this acute context is weight-based.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Hydroxocobalamin Injection

Evidence for Use in Vitamin B12 Deficiency Syndromes

Research has explored the use of Hydroxocobalamin injection in contexts where the body lacks sufficient Vitamin B12, such as pernicious anemia or malabsorption disorders. This research includes long-standing observational cohort studies and clinical follow-up reports that was observed in adults diagnosed with this deficiency. Research examined various measurable changes related to systemic or functional imbalance, specifically tracking measurable changes in the blood and certain body substances.

Studies monitored important markers like red blood cell levels and the specific substances in the blood, such as methylmalonic acid (MMA) and total homocysteine (tHcy). Research describes the monitoring of levels for specific biomarkers in individuals with deficiency following administration. Because ethical considerations govern the design of clinical trials in this area, the evidence for the immediate, acute phase relies on consistent historical reports and observational data.

Evidence for Use in Acute Cyanide Poisoning

A different body of research has been studied for its use as an antidote in emergency situations, specifically for acute cyanide poisoning. Due to the critical and immediate nature of this indication, research could not involve traditional randomized controlled trials against placebo.

Instead, the evidence is derived from emergency observational settings, including uncontrolled clinical studies and retrospective analyses of patients, often those who experienced poisoning from smoke inhalation. Studies monitored outcomes linked to physiological strain or stress, such as the patient's survival rate and measurements of rapid shifts in metabolic imbalance. Findings from these studies describe patterns related to the acute physiological response.

Research Gaps and What Remains Uncertain

The research for Hydroxocobalamin injection includes areas where more data is needed. Comparative evidence is lacking for many aspects, such as long-term studies directly comparing Hydroxocobalamin against other B12 injection forms. Furthermore, the evidence base is composed largely of observational data rather than large-scale randomized trials. Some studies have explored the injection for investigational uses; however, these findings were mixed, and the data are still emerging. The evidence highlights what is known, and what is still uncertain, particularly regarding long-term, functional outcomes and the limited data available for investigational contexts.

Key Studies & References

  1. Hydroxocobalamin (Vitamin B12) Injection: Full Prescribing Information and Label

Frequently Asked Questions (FAQ)

Common questions about Hydroxocobalamin injection (FAQ)

Q: Are there any common foods or supplements that interact with the Hydroxocobalamin injection?

Official documents indicate there are no known interactions with common foods or drinks. The label notes a specific incompatibility with Ascorbic Acid (Vitamin C) if mixed in the same intravenous line. Additionally, official information suggests that consuming large amounts of alcohol may reduce the level of vitamin B12 in the body.

Q: What kind of evidence supports the use of Hydroxocobalamin for nerve issues?

The drug is prescribed to correct B12 deficiency, a condition associated with neurological problems. Its biochemical mechanism supports the structural integrity of the myelin sheath (the protective layer around nerve cells) and nerve cell function by helping to correct defects in the body’s lipid (fat) metabolism.

Q: Why is this injection sometimes used for cyanide poisoning?

According to the official product information for this emergency use, the drug functions as a complexation agent. This means it tightly binds to cyanide ions, converting the poison into a non-toxic compound called Cyanocobalamin, which the kidneys can then excrete.

Q: Why do some people with certain medical conditions need lifelong Hydroxocobalamin injections?

The long-term, intermittent schedule is typically required for people with chronic medical conditions, such as pernicious anemia, that permanently prevent the body from being able to effectively absorb vitamin B12 from food (a condition known as malabsorption).

Q: Is Hydroxocobalamin injection the same as Cyanocobalamin? What's the difference?

No, official sources describe them as different forms of Vitamin B12. Hydroxocobalamin is considered a naturally occurring form that demonstrates a higher retention rate in the body. Cyanocobalamin is a synthetic form that the body must convert before it can be utilized.

Q: Why is Hydroxocobalamin given as an injection instead of a pill?

It is administered by injection because certain underlying conditions, such as the lack of intrinsic factor (malabsorption) in the stomach, prevent the body from effectively absorbing the vitamin when it is taken orally.

Q: Is it normal to feel tired right after getting the Hydroxocobalamin shot?

Fatigue or tiredness is not listed among the most commonly reported side effects in official regulatory documents.

Q: What are the most common side effects people notice from this injection?

Common reported side effects include diarrhea, rash, itching, pain at the injection site, and a temporary red coloring of the urine ( chromaturia).

Q: Does the injection site pain or redness last a long time?

Pain or redness at the injection site is listed in regulatory documents as a common, mild, and usually transient side effect.

Q: Can people with kidney problems use Hydroxocobalamin injection?

Official documents advise that caution and close monitoring are necessary for people with existing kidney problems. This is because acute renal failure has been reported in certain settings, particularly with high-dose use. The decision to use this medication in such circumstances is determined by a healthcare provider.

Q: Is Hydroxocobalamin injection safe to use during pregnancy?

For treating a B12 deficiency, the drug can be used, as treating the deficiency is considered important for maternal and fetal health. For its use in cyanide poisoning, official guidance indicates the benefits of the life-saving treatment generally outweigh the potential risks.

Q: What should I watch out for that might be a serious side effect?

Serious side effects listed in the product information include signs of a severe allergic reaction (e.g., swelling or difficulty breathing) and symptoms related to potentially high blood pressure (e.g., severe headache or blurred vision).

Q: Does Hydroxocobalamin injection affect blood pressure?

Official documents note that substantial increases in blood pressure may occur, particularly when the high doses are used for cyanide poisoning. Monitoring blood pressure during treatment is advised in such cases.

Q: What are the high-level reasons someone might not be eligible for this medicine?

The official label states that people who have a known hypersensitivity or allergy to Hydroxocobalamin, Cobalt, or any other component in the injection are generally not eligible.

Q: Is it normal for urine to change color after receiving the injection?

Yes, official documents note that a red coloring of the urine ( chromaturia) is a common and expected side effect, which may last for several weeks.

Q: Do antibiotics interfere with the Hydroxocobalamin injection?

Certain drugs, including Chloramphenicol, have been reported to interact with Hydroxocobalamin and may affect its effectiveness.

Q: What type of blood tests are used to monitor Hydroxocobalamin treatment?

Due to its deep red color, Hydroxocobalamin may interfere with the results of certain laboratory tests, including clinical chemistry, hematology, and urine parameters.

Q: Can patients with heart conditions safely receive Hydroxocobalamin?

Official documents advise caution and monitoring for people with certain heart conditions (e.g., congestive heart failure). The medication may be associated with changes in heart rate or blood pressure.

Q: Can someone be allergic to Hydroxocobalamin?

Yes, the official label explicitly states the drug is contraindicated in people with known hypersensitivity or allergy to Hydroxocobalamin, B12, or Cobalt. Serious allergic reactions have been reported.

Q: Is Hydroxocobalamin injection affected by exposure to sunlight?

The drug formulation itself is sensitive to light. Furthermore, official labels advise that if the skin becomes red after the injection, that exposure to sunlight or tanning beds should be avoided until the skin color returns to normal.

Q: What should I know about the safety profile of Hydroxocobalamin injection?

The safety profile includes the potential risk of allergic reactions, the potential for blood pressure increases, and the need to monitor patients with underlying kidney or heart conditions, according to official warnings.

Q: Why is B12 deficiency sometimes referred to as 'pernicious anemia'?

The B12 deficiency that the injection treats is often caused by a condition called pernicious anemia, which is a form of anemia resulting from the body's inability to absorb B12 from food due to a lack of intrinsic factor.

Q: Can alcohol consumption affect the Hydroxocobalamin injection?

Official sources indicate that it is unknown if drinking alcohol will affect the drug directly. However, consuming large amounts of alcohol may lower the body's overall levels of vitamin B12.

Q: Is Hydroxocobalamin injection derived from natural or synthetic sources?

Official chemical documentation indicates that Hydroxocobalamin is considered a naturally occurring form of vitamin B12, which is typically produced by bacteria.

Q: Can this injection cause any issues with my vision?

Certain severe side effects, such as a severe headache or blurred vision, are listed in official documents as symptoms that may occur if the drug causes dangerously high blood pressure.

Q: What is the difference between B12 deficiency and B12 malabsorption?

B12 deficiency is the overall condition of having low B12 levels. Malabsorption is a common cause of deficiency, where the body cannot absorb B12 from food.

Q: Can taking high doses of Vitamin C affect how Hydroxocobalamin works in the body?

Yes, official sources report chemical incompatibility with Ascorbic Acid (Vitamin C); therefore, they should not be administered simultaneously through the same IV line.

Q: Is it normal to experience mild headaches after the injection?

Headache is listed among the commonly reported side effects of the Hydroxocobalamin injection in official documents.

How should Hydroxocobalamin injection be stored and disposed of?

How to Store and Dispose of Hydroxocobalamin Injection

Hydroxocobalamin injection must be stored under specific environmental conditions defined by regulatory labeling to ensure stability.

Storage Requirements

Requirement Condition
Temperature Controlled Room Temperature: 20 C to 25 C (68 F to 77 F)
Light Protection Must be protected from light and stored in the original container
Safety Keep out of the reach and sight of children

Disposal Instructions

Unused or expired medication must be disposed of according to local requirements. All used needles and syringes must be placed immediately into a designated, puncture-resistant sharps disposal container. The sharps container should not be discarded in household trash unless permitted by local guidelines.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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