TAM (Treatments and Medicines) NHS Highland
Important: Therapy notes
MHRA advice: Vitamin B12 (hydroxocobalamin, cyanocobalamin): advise patients with known cobalt allergy to be vigilant for sensitivity reactions (December 2023) (www.gov.uk).
Drugs used in megaloblastic anaemias (Formulary)
Important: Therapy notes
- Folic acid 5mg daily is used in folate-deficient megaloblastic anaemia.
- Most megaloblastic anaemias result from a lack of either vitamin B12or folate. It is essential to establish in every case which deficiency is present and the underlying cause before initiating treatment.
- For prophylaxis in chronic haemolytic states it is sufficient to give folic acid 5mg daily or even weekly, depending on the diet and the rate of haemolysis.
- Never give folic acid alone in the treatment of pernicious anaemia and other vitamin B12 deficiency states because it may precipitate the onset of subacute combined degeneration of the spinal cord. If in doubt discuss with haematologist.
- Folic acid is also given at a dose of 400 micrograms daily to prevent the first occurrence of neural tube defects. It should be started as soon as pregnancy is planned or confirmed and continued until week 12 of pregnancy.
- To prevent the recurrence of neural tube defects give one 5mg tablet daily up to week 12 of pregnancy.
- Women wishing to become pregnant, with coeliac disease or diabetes or if taking antiepileptic medicines should be advised to take 5mg folic acid supplementation daily, starting at least one month before conception and continuing up to week 12 of pregnancy.
- For more information on nutrition in pregnancy see NICE guideline NG247: Maternal and child nutrition: nutrition and weight management in pregnancy, and nutrition in children up to 5 years and Pre-pregnancy, antenatal and postnatal care guidance for women with obesity.
- For advice on use of folic acid with methotrexate in inflammatory bowel disease see Chronic bowel disorders, in rheumatic disease see Drugs used in rheumatic diseases and gout and in dermatological conditions see Preparations for eczema and psoriasis.