This information is intended for use by health professionals

1. Name of the medicinal product


Hydroxocobalamin 1000 microgram/ml Injection

2. Qualitative and quantitative composition

Anhydrous hydroxocobalamin 1000mcg/ml.

3. Pharmaceutical form


4. Clinical particulars
4.1 Therapeutic indications

Treatment of Addisonian pernicious anaemia.

Prophylaxis and treatment of other macrocytic anaemias due to vitamin B12 deficiency.

Treatment of tobacco amblyopia.

Treatment of Leber' s atrophy.

4.2 Posology and method of administration

The following dosages are suitable for children and adults.

Addisonian pernicious anaemia and other macrocytic anaemias without neurological involvement:


250 micrograms to 1000 micrograms intramuscularly on alternate days for one or two weeks then 250 micrograms weekly until blood count is normal.


1000 micrograms every two or three months.

Addisonian pernicious anaemia and other macrocytic anaemias with neurological involvement:


1000 micrograms on alternate days as long as improvement continues.


1000 micrograms every two months.

Prophylaxis of macrocytic anaemias associated with vitamin B12 deficiency resulting from gastrectomy, ileal resection, certain ma/absorption states and vegetarianism:

1000 micrograms every two or three months.

Tobacco amblyopia and Leber's optic atrophy:


1000 micrograms daily by intramuscular injection for two weeks then twice weekly as long as improvement is maintained.


1000 micrograms every three months or as required.

4.3 Contraindications

Sensitivity to hydroxocobalamin / vitamin B12.

4.4 Special warnings and precautions for use

This medicine should not be given before a megaloblastic marrow has been demonstrated. Regular monitoring of the blood is advisable. Doses of hydroxocobalamin greater than 10 micrograms daily may produce a haematological response in patients with folate deficiency. Indiscriminate use may mask the exact diagnosis. Cardiac arrhythmias secondary to hypokalaemia have been reported during initial therapy and plasma potassium should, therefore, be monitored during this period.

4.5 Interaction with other medicinal products and other forms of interaction

The serum concentration of hydroxocobalamin may be reduced by concurrent administration of oral contraceptives. Chlorphenicol-treated patients may respond poorly to hydroxocobalamin. Vitamin B12 assays by microbiological techniques are invalidated by antimetabolites and most antibiotics.

4.6 Pregnancy and lactation

Hydroxocobalamin should not be used to treat megaloblastic anaemia of pregnancy.

4.7 Effects on ability to drive and use machines

None stated.

4.8 Undesirable effects

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

Disorders of the immune system:


Allergic hypersensitivity reactions

Very rare:


Gastro intestinal disorders:

Frequency Not Known:


General disorders:

Frequency Not Known:

Fever, dizziness, Injection site disorders

Neurological disorders:

Frequency Not Known:


4.9 Overdose

Treatment is unlikely to be needed in cases of overdosage.

5. Pharmacological properties
5.1 Pharmacodynamic properties

Vitamin B12

ATC classification: B03B A03

5.2 Pharmacokinetic properties

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. It is stored in the liver, excreted in the bile, and undergoes enterohepatic recycling; part of a dose is excreted in the urine, most of it in the first 8 hours.

5.3 Preclinical safety data

There are no pre-clinical data of relevance to the prescriber which are additional to that already included in other sections of the Summary of Product Characteristics.

6. Pharmaceutical particulars
6.1 List of excipients

Sodium dihydrogen orthophosphate

Sodium chloride

Sodium Hydroxide (for pH adjustment)

Hydrochloric Acid (for pH adjustment)

Water for Injections

6.2 Incompatibilities

None stated.

6.3 Shelf life

36 months

6.4 Special precautions for storage

Protect from light. Store below 25°C.

6.5 Nature and contents of container

This medicine is supplied in clear 1ml Type I glass ampoules in cartons of 5 or 10.

6.6 Special precautions for disposal and other handling

None stated.

7. Marketing authorisation holder

Amdipharm UK Limited

Capital House, 85 King William Street,

London EC4N 7BL, UK

8. Marketing authorisation number(s)

PL 20072/0217

9. Date of first authorisation/renewal of the authorisation

18th June 1993 / 6th November 1998

10. Date of revision of the text