Drugs List

Therapeutic Indications

Uses

Leber's optic atrophy
Macrocytic anaemia due to B12 deficiency: prophylaxis
Macrocytic anaemia with neurological involvement: Treatment
Macrocytic anaemia without neurological involvement: Treatment
Tobacco amblyopia

Unlicensed Uses

Congenital transcobalamin II deficiency
Homocystinuria
Methylmalonic acidaemia

Contraindications

None known

Precautions and Warnings

Hypokalaemia
Pregnancy

Folate deficiency: Indiscriminate administration may mask true diagnosis
Chloramphenicol treated patients may respond poorly
Confirm diagnosis of vitamin B12 deficiency before initiating treatment
Exclude folate deficiency as cause of megaloblastic anaemia
Monitor serum potassium on initiation as hypokalaemia can occur
Monitor haematological parameters regularly throughout treatment
Monitor platelet count for thrombocytosis in first weeks of treatment
Antibodies to ingredient may develop
Most antibiotics invalidate Vitamin B12 assays by microbiological technique

Pregnancy and Lactation

Pregnancy

Use hydroxocobalamin with caution during pregnancy.

Hydroxocobalamin supplementation is not routinely needed when pregnant. Anaemia caused by a vitamin B12 deficiency should be treated during pregnancy (Schaefer, 2015). Severe maternal vitamin B12 deficiency during pregnancy may lead to subsequent infertility and poor pregnancy outcome, however less severe deficiencies are not thought to be harmful to mother of foetus (Briggs, 2015).

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Hydroxocobalamin is considered safe for use during breastfeeding.

Hydroxocobalamin is secreted in breast milk but it is not expected to cause harm in the infant.

There have been reports of megaloblastic anaemia in infants nursing from vitamin B12 deficient mothers. The American Academy of Paediatrics classifies vitamin B12 as compatible with breastfeeding (Briggs, 2015).

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Acne-like eruptions
Anaphylaxis
Arrhythmias secondary to hypokalaemia
Bullous eruption
Chills
Chromaturia
Diarrhoea
Dizziness
Fever
Headache
Hot flushes
Hypersensitivity reactions
Hypokalaemia
Injection site reactions
Malaise
Nausea
Pain
Paraesthesia
Pruritus
Rash
Sensory disturbances
Thrombocytosis
Tremor
Vomiting

Presentation

Solution for injection containing hydroxocobalamin

Drugs List

Therapeutic Indications

Uses

Leber's optic atrophy
Macrocytic anaemia due to B12 deficiency: prophylaxis
Macrocytic anaemia with neurological involvement: Treatment
Macrocytic anaemia without neurological involvement: Treatment
Tobacco amblyopia

Unlicensed Uses

Congenital transcobalamin II deficiency
Homocystinuria
Methylmalonic acidaemia

Dosage

Adults

Children

Neonates

Contraindications

None known

Precautions and Warnings

Hypokalaemia
Pregnancy

Folate deficiency: Indiscriminate administration may mask true diagnosis
Chloramphenicol treated patients may respond poorly
Confirm diagnosis of vitamin B12 deficiency before initiating treatment
Exclude folate deficiency as cause of megaloblastic anaemia
Monitor serum potassium on initiation as hypokalaemia can occur
Monitor haematological parameters regularly throughout treatment
Monitor platelet count for thrombocytosis in first weeks of treatment
Antibodies to ingredient may develop
Most antibiotics invalidate Vitamin B12 assays by microbiological technique

Pregnancy and Lactation

Pregnancy

Use hydroxocobalamin with caution during pregnancy.

Hydroxocobalamin supplementation is not routinely needed when pregnant. Anaemia caused by a vitamin B12 deficiency should be treated during pregnancy (Schaefer, 2015). Severe maternal vitamin B12 deficiency during pregnancy may lead to subsequent infertility and poor pregnancy outcome, however less severe deficiencies are not thought to be harmful to mother of foetus (Briggs, 2015).

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Hydroxocobalamin is considered safe for use during breastfeeding.

Hydroxocobalamin is secreted in breast milk but it is not expected to cause harm in the infant.

There have been reports of megaloblastic anaemia in infants nursing from vitamin B12 deficient mothers. The American Academy of Paediatrics classifies vitamin B12 as compatible with breastfeeding (Briggs, 2015).

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Acne-like eruptions
Anaphylaxis
Arrhythmias secondary to hypokalaemia
Bullous eruption
Chills
Chromaturia
Diarrhoea
Dizziness
Fever
Headache
Hot flushes
Hypersensitivity reactions
Hypokalaemia
Injection site reactions
Malaise
Nausea
Pain
Paraesthesia
Pruritus
Rash
Sensory disturbances
Thrombocytosis
Tremor
Vomiting

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: June 2017

Reference Sources

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

Summary of Product Characteristics: Cobalin-H injection. Concordia International - formerly AMCo. Revised February 2018.
Summary of Product Characteristics: Hydroxocobalamin 1mg in 1ml solution for injection. Auden Mckenzie (Pharma Division) Ltd (a subsidiary of Actavis PLC). Revised Augsut 2017.
Summary of Product Characteristics: Hydroxocobalamin Injection BP 1mg/ml. Concordia International - formerly AMCo. Revised March 2018.
Summary of Product Characteristics: Neo-Cytamen 1000 micrograms/ml solution for injection. RPH Pharmaceuticals AB. Revised January 2015.

NICE - Evidence Services Available at: www.nice.org.uk Last accessed: 12 Novemeber 2018