Page 59 - Essential Haematology

Chapter 3 Hypochromic anaemias / 45

cell antibodies, Helicobacter infection and serum
Table 3.5 Failure of response to oral iron.

gastrin level may help to diagnose autoimmune gas-

tritis. In difficult cases a camera in a capsule can be

Continuing haemorrhage
swallowed which relays pictures of the gastrointes-
tinal tract electronically. Tests for transglutaminase Failure to take tablets
antibodies and duodenal biopsy to look for gluten - Wrong diagnosis – especially thalassaemia trait,
induced enteropathy can be valuable. Hookworm sideroblastic anaemia
ova are sought in stools of subjects from areas where
Mixed defi ciency – associated folate or vitamin
this infestation occurs. Rarely, a coeliac axis angi-
B 12 defi ciency
ogram is needed to demonstrate angiodysplasia.
If gastrointestinal blood loss is excluded, loss of Another cause for anaemia (e.g. malignancy,
infl ammation)
iron in the urine as haematuria or haemosiderinuria
(resulting from chronic intravascular haemolysis) Malabsorption – coeliac disease, atrophic
is considered. A normal chest X - ray excludes gastritis, Helicobacter infection
the rare condition of pulmonary haemosiderosis. Use of slow - release preparation
Rarely, patients bleed themselves producing iron
defi ciency.

Treatment
Parenteral i ron
The underlying cause is treated as far as possible. In

addition, iron is given to correct the anaemia and Th ree preparations are available in the UK. Th e
replenish iron stores. dose is calculated according to body weight and
degree of anaemia. Ferric hydroxide - sucrose
®

(Venofer ) is administered by slow intravenous
Oral i ron
injection or infusion, usually 200 mg iron in each
®

The best preparation is ferrous sulphate which is infusion. Iron dextran (CosmoFer ) can be given
cheap, contains 67 mg iron in each 200 - mg tablet as slow intravenous injection or infusion either in

and is best given on an empty stomach in doses small single doses or as a total dose infusion given

®
spaced by at least 6 hours. If side - effects occur (e.g. in one day. Ferric carboxymaltose (Ferinject ) is

nausea, abdominal pain, constipation or diarrhoea), also given by slow intravenous injection or infu-

®
these can be reduced by giving iron with food or by sion. In the USA, ferumoxytol (Feraheme ) is also
using a preparation of lower iron content (e.g. licensed for chronic renal failure. Th ere may be
ferrous gluconate which contains less iron (37 mg) hypersensitivity or anaphylactoid reactions so

per 300 - mg tablet). An elixir is available for parenteral iron is only given when there are high
children. Slow - release preparations should not be iron requirements as in gastrointestinal bleeding,
used. severe menorrhagia, chronic haemodialysis, with
Oral iron therapy should be given for long erythropoietin therapy, and when oral iron is inef-
enough both to correct the anaemia and to replen- fective (e.g. iron malabsorption resulting from
ish body iron stores, which usually means for at least gluten - induced enteropathy or atrophic gastritis)
6 months. The haemoglobin should rise at the rate or impractical (e.g. active Crohn ’ s disease). Th e

of approximately 2 g/dL every 3 weeks. Failure of haematological response to parenteral iron is no
response to oral iron has several possible causes faster than to adequate dosage of oral iron but the
(Table 3.5 ) which should all be considered before stores are replenished faster. Intravenous iron has
parenteral iron is used. also been found to increase functional capacity
Iron fortification of the diet in infants in Africa and quality of life in some patients with conges-

reduces the incidence of anaemia but increases tive heart failure, even in the absence of anaemia
suceptibility to malaria. (see p. 387 ).