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Drug Details

NEO-CYTAMEN

• Drug Class Description
  Vitamin B (B12 vitamins).
• Generic Name
  Hydroxocobalamin
• Presentation
  Solution for injection.
• Description
  Hydroxocobalamin chloride 1.027mg equivalent to 1.0 mg Hydroxocobalamin.
• Indications
  Addisonian pernicious anaemia. Prophylaxis and treatment of other macrocytic anaemias associated with vitamin B12 deficiency. Tobacco amblyopia and Leber's optic atrophy.
• Adult Dosage
  

  Route of administration: Intramuscular.

  Adults and Children

  Addisonian pernicious anaemia and other macrocytic anaemias without neurological involvement:

  Initially: 250 to 1000mcg intramuscularly on alternate days for one to two weeks, then 250mcg weekly until the blood count is normal.

  Maintenance: 1000mcg every two to three months.

  Addisonian pernicious anaemia and other macrocytic anaemias with neurological involvement:

  Initially: 1000mcg on alternate days as long as improvement is occurring.

  Maintenance: 1000mcg every two months.

  Prophylaxis of macrocytic anaemia associated with vitamin B₁₂ deficiency resulting from gastrectomy, some malabsorption syndromes and strict vegetarianism:

  1000mcg every two to three months.

  Tobacco amblyopia and Leber's optic atrophy:

  Initially: 1000mcg or more daily by intramuscular injection for two weeks. Then twice weekly as long as improvement is occurring.

  Maintenance: 1000mcg monthly.

• Contra Indications
  

  Hypersensitivity to any ingredient of the preparation.

  Hydroxocobalamin should not be used for treatment of megaloblastic anaemia of pregnancy unless vitamin B12 deficiency has been demonstrated.

• Special Precautions
  

  Precautions:

  The dosage schemes given above are usually satisfactory, but regular examination of the blood is advisable. If megaloblastic anaemia fails to respond to hydroxocobalamin, folate metabolism should be investigated. Doses in excess of 10mcg daily may produce a haematological response in patients with folate deficiency. Indiscriminate administration may mask the true diagnosis. The haematological and neurological state should be monitored regularly to ensure adequacy of therapy. Cardiac arrhythmias secondary to hypokalaemia during initial therapy have been reported. Plasma potassium should therefore be monitored during this period. Platelet count should be monitored during the first weeks of use in megaloblastic anaemia due to the possible occurrence of reactive thrombocytosis.

• Interactions
  

  Chloramphenicol-treated patients may respond poorly to hydroxocobalamin. Serum concentrations of hydroxocobalamin may be lowered by oral contraceptives but this interaction is unlikely to have clinical significance. Antimetabolites and most antibiotics invalidate vitamin B₁₂ assays by microbiological techniques.

• Adverse Drug Reactions
  

  The following effects have been reported and are listed below by body system:

  Blood and lymphatic system disorders

  Reactive thrombocytosis can occur during the first weeks of use in megaloblastic anaemia.

  Cardiovascular disorders:

  Arrhythmias secondary to hypokalaemia.

  Disorders of the immune system:

  Hypersensitivity reactions including skin reactions (e.g. rash, itching) and exceptionally anaphylaxis.

  Gastro intestinal disorders:

  Nausea, vomiting, diarrhoea.

  General disorders:

  Fever, chills, hot flushing, dizziness, malaise, pain. Injection site reactions including injection site pain, injection site erythema, injection site pruritus, injection site induration, and injection site swelling.

  Neurological disorders:

  Headache, sensory abnormalities such as paraesthesiae.

  Tremor.

  Renal and unrinary disorders:

  Chromaturia

  Skin and subcutaneous tissue disorders:

  Acneiform and bullous eruptions.