Pernicious Anaemia - treatment

Once diagnosed, British National Formulary [1] and British National Formulary for Children [2] give clear guidelines:

Treatment for Adults

For adults, the guidelines are (you will need a log-on to access the online page)

 9 Nutrition and blood > 9.1 Anaemias and some other blood disorders > 9.1.2 Drugs used in megaloblastic anaemias

HYDROXOCOBALAMIN

Additional information interactions (Hydroxocobalamin).

Indications

 see under dose below

Cautions

 should not be given before diagnosis fully established but see also notes above; interactions:Appendix 1 (hydroxocobalamin)

Side-effects

 nausea, headache, dizziness; fever, hypersensitivity reactions (including rash and pruritus); injection-site reactions; hypokalaemia and thrombocytosis during initial treatment; chromaturia

Dose

 By intramuscular injection, pernicious anaemia and other macrocytic anaemias without neurological involvement, initially 1 mg 3 times a week for 2 weeks then 1 mg every 3 months

Pernicious anaemia and other macrocytic anaemias with neurological involvement, initially 1 mg on alternate days until no further improvement, then 1 mg every 2 months

Prophylaxis of macrocytic anaemias associated with vitamin B₁₂ deficiency, 1 mg every 2–3 months

Tobacco amblyopia and Leber’s optic atrophy, initially 1 mg daily for 2 weeks, then 1 mg twice weekly until no further improvement, thereafter 1 mg every 1–3 months

child see BNF for Children

Cyanide poisoning [not licensed], see Emergency Treatment of Poisoning

Treatment for children

BNF for Children > 9 Nutrition and blood > 9.1 Anaemias and some other blood disorders > 9.1.2 Drugs used in megaloblastic anaemias

HYDROXOCOBALAMIN

Additional information: interactions (Hydroxocobalamin).

Cautions 

should not be given before diagnosis fully established but see also notes above; interactionsAppendix 1 (hydroxocobalamin)

Side-effects 

itching, exanthema; fever, chills, hot flushes; nausea, dizziness; initial hypokalaemia; rarely acneform and bullous eruptions; anaphylaxis

Licensed use 

licensed for use in children (age not specified by manufacturers); not licensed for use in inborn errors of metabolism

Indications and dose

Macrocytic anaemia without neurological involvement

By intramuscular injection

Child 1 month–18 years 

initially 250 micrograms–1 mg 3 times a week for 2 weeks then 250 micrograms once weekly until blood count normal, then 1 mg every 3 months

Macrocytic anaemia with neurological involvement

By intramuscular injection

Child 1 month–18 years 

initially 1 mg on alternate days until no further improvement, then 1 mg every 2 months

Prophylaxis of macrocytic anaemias associated with vitamin B₁₂ deficiency

By intramuscular injection

Child 1 month–18 years 

1 mg every 2–3 months

Leber’s optic atrophy

By intramuscular injection

initially 1 mg daily for 2 weeks, then 1 mg twice weekly until no further improvement, thereafter 1 mg every 1–3 months

Congenital transcobalamin II deficiency

By intramuscular injection

Neonate 

1 mg 3 times a week, reduce after 1 year to 1 mg once weekly or as appropriate

Child 1 month–18 years 

1 mg 3 times a week, reduce after 1 year to 1 mg once weekly or as appropriate

Methylmalonic acidaemia and homocystinuria

By intramuscular injection

Child 1 month–18 years 

initially 1 mg daily for 5–7 days, reduce according to response to maintenance dose of up to 1 mg once or twice weekly

Methylmalonic acidaemia, maintenance once intramuscular response established

By mouth

Child 1 month–18 years 

5–10 mg once or twice weekly

Note: Some children do not respond to the oral route

B₁₂ deficiency Patient Support Group view

Whilst we are not clinicians, we assert boldly that every person is different.  This simplistic view that every adult should fall into one of two categories, either “without neurological symptoms” or “with neurological symptoms” doesn’t concur with our members’ own experiences nor those of the Pernicious Anaemia Society’s members.

For some people, bi-monthly or tri-monthly injections are adequate.  Some can make use of cyanocobalamin, some require methylcobalamin.  For all of us, we can tell when we need our next injection, whether it is after 2 months, after 1 week, after a couple of days. See also the article in September’s Saga magazine – “injection that gives back lost months” [3]

.

Surely the same will apply to children?

Citations

1.            BNF, British National Formulary. 2009, Joint Formulary Committee, British Medical Association & Royal Pharmaceutical Society of Great Britain, JFC.

2.            BNFC, British National Formulary for Children. 2008, Paediatric Formulary Committee, BMJ Publishing, RPS Publishing and RCPCH Publications.

3.            Hobson, J., New techniques in medicine: injection that gives back lost months, in Choice. 2009, Saga. p. 60-61.