Addisonian pernicious anaemia.

Prophylaxis and treatment of other macrocytic anaemias associated with vitamin B₁₂ deficiency.

Tobacco amblyopia and Leber's optic atrophy.

Posology

Adults and Children

Addisonian pernicious anaemia and other macrocytic anaemias without neurological involvement:

Addisonian pernicious anaemia and other macrocytic anaemias with neurological involvement:

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:

Method of administration

Intramuscular injection

Hypersensitivity to any ingredient of the preparation.

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

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

Cardiac arrhythmias secondary to hypokalaemia during initial therapy have been reported. Plasma potassium should therefore be monitored during this period.

Reactive thrombocytosis

Platelet count should be monitored during the first weeks of use in megaloblastic anaemia due to the possible occurrence of reactive thrombocytosis.

Sodium

This medicinal product contains less than 1 mmol sodium (23 mg) per dose, that is to say essentially 'sodium-free'

Chloramphenicol

Chloramphenicol-treated patients may respond poorly to Neo-Cytamen.

Oral contraceptives

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.

Pregnancy

Neo-Cytamen should not be used for the treatment of megaloblastic anaemia of pregnancy unless vitamin B₁₂ deficiency has been demonstrated.

Breast-feeding

Neo-Cytamen is secreted into breast milk but this is unlikely to harm the infant, and may be beneficial if the mother and infant are vitamin B₁₂ deficient.

Fertility

No data available

None stated.

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.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme Website www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Treatment is unlikely to be needed in cases of overdosage.

Pharmacotherapeutic group: Antianaemic preparations -Vitamin B₁₂

ATC code: B03BA03

Distribution

Vitamin B12 is extensively bound to specific plasma proteins called transcobalamins; transcobalamin II appears to be involved in the rapid transport of the cobalamins to tissues.

Elimination

Vitamin B12 is stored in the liver, excreted in the bile, and undergoes extensive enterohepatic recycling; part of an administered dose is excreted in the urine, most of it in the first 8 hours; urinary excretion, however, accounts for only a small fraction in the reduction of total body stores acquired by dietary means. Vitamin B12 diffuses across the placenta and also appears in breast milk.

An intramuscular injection of hydroxocobalamin produces higher serum levels than the same dose of cyanocobalamin, and these levels are well maintained. After injection of hydroxocobalamin, 90% of a 100 microgram dose and 30% of a 1000 microgram dose are retained.

None stated.

Sodium chloride, acetic acid, Water for Injections.

None.

36 months.

Protect from light. Do not store above 25° C.

Clear, one-point cut (OPC) glass Type 1 ampoules packed in cartons of 5 x 1ml ampoules

Not applicable.