9.1.1 Iron-Deficiency Anaemias
Ferrous fumarate (tablets 210mg containing 68mg iron/tablet) is the recommended agent for the treatment and prophylaxis of iron deficiency anaemia.
Sodium feredetate/sodium ironedetate (elixir containing 27.5mg iron/5mL) is the recommended liquid iron formulation. It is palatable, sugar-free and does not stain dental enamel. This product is more expensive than other recommended products and should only be used for children or adults unable to take tablets.
Ferrograd® (m/r tablets containing ferrous sulphate equivalent to 105mg iron/tablet) is a modified-release iron preparation. Its use should be limited to those patients where compliance is a major problem; modified-release preparations offer no therapeutic advantage over ferrous sulphate tablets.
Ferrograd Folic® (m/r tablets containing ferrous sulphate equivalent to 105mg iron + 350 micrograms folic acid/tablet) is indicated for the prevention of iron and folic acid deficiency in pregnancy and maintenance therapy in renal dialysis. There is no justification for use outwith these indications.
Pregaday® (tablets containing ferrous fumarate equivalent to 100mg iron + 350 micrograms folic acid/tablet) is used at Aberdeen Maternity Hospital for patients who are intolerant of ferrous sulphate.
Iron sucrose (injection) containing a complex of ferric hydroxide with sucrose containing 2% (20mg/mL) of iron. Parenteral administration should only be considered when oral therapy has failed due to lack of patient co-operation, severe gastro-intestinal side-effects, continuing blood loss, or malabsorption.
PRESCRIBING POINTS FOR IRON-DEFICIENCY ANAEMIAS
- The oral dose of elemental iron for the treatment of iron-deficiency anaemia is 100 to 200mg/day. Treatment should continue for three months after haemoglobin has returned to normal in an attempt to replenish iron stores.
- Tolerance of iron preparations is improved by starting with a small dose and increasing the dose over a few days.
- Although iron preparations are best absorbed when taken on an empty stomach, they are commonly taken with food to reduce gastro-intestinal side-effects.
- Modified-release iron preparations carry the iron past the first part of the duodenum to parts of the gut where absorption is poor. Due to less dissolved iron being present in the intestinal lumen at any one time, these preparations may produce fewer side-effects than conventional iron preparations. However, the low incidence of side-effects may be because of the small amounts of iron available under these conditions and so the preparations have limited therapeutic advantage.
- Iron preparations taken orally may have a constipating effect, particularly in older patients, occasionally leading to faecal impaction. They may also cause diarrhoea.