Hydroxocobalamin G.L. Pharma (Hydroxocobalamin Acetate)

Hydroxocobalamin acts as a vitamin B12 replacement in conditions where cobalamin is deficient or its activity is required.

• Vitamin B12 deficiency: restores normal hematologic parameters and neurological function.
• Pernicious anemia: supports erythropoiesis and reduces anemia symptoms.
• Cyanide poisoning: binds cyanide ions to form non‑toxic cyanocobalamin, facilitating detoxification.

• Hydroxocobalamin serves as a cofactor for methionine synthase and methylmalonyl‑CoA mutase, enzymes essential for DNA synthesis, myelin formation and erythrocyte maturation. After intramuscular or subcutaneous administration, it is converted to active cobalamin forms (methylcobalamin and adenosylcobalamin) that participate in one‑carbon metabolism and fatty‑acid catabolism, while also directly binding cyanide to produce cyanocobalamin for safe excretion.

Hydroxocobalamin may cause a range of adverse reactions following injection.

Common Side Effects

• Injection site pain: mild to moderate discomfort at the injection site.
• Erythema or swelling: localized redness or edema.
• Mild fever: transient elevation of body temperature.
• Headache: occasional throbbing sensation.
• Nausea: brief feeling of queasiness.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Hypotension or hypertension: abrupt changes in blood pressure.
• Angioedema: swelling of face, lips or throat.
• Serum sickness‑like reaction: fever, rash and arthralgia.
• Severe injection site necrosis: tissue damage at the site.

Before initiating therapy, clinicians should consider several safety measures.

• Baseline assessment: evaluate serum B12 levels and hematologic status.
• Hypersensitivity monitoring: watch for signs of allergic reaction during and after injection.
• Renal impairment: use caution in patients with severe kidney disease.
• Known cobalamin allergy: avoid administration if hypersensitivity to hydroxocobalamin is documented.
• Pregnancy and lactation: prescribe only if the potential benefit outweighs any uncertain risk.
• Store at ambient temperature: keep in original container, protect from moisture and light.

Hydroxocobalamin can interact with other agents that affect cobalamin metabolism or cardiovascular status.

Major Interactions (Avoid)

• Nitrous oxide anesthesia: inactivates vitamin B12 and may precipitate severe deficiency.
• High‑dose intravenous cyanide antidotes: may compete for binding sites.

Moderate Interactions (Monitor Closely)

• Metformin: may reduce B12 absorption; monitor serum levels.
• Proton pump inhibitors or H2 blockers: can impair oral B12 uptake, though less relevant for injectable form.
• Certain chemotherapy agents (e.g., methotrexate): may increase demand for B12; observe hematologic parameters.