Page 70 - Essential Haematology

56 / Chapter 4 Iron overload

18 It is usual to attempt to keep the ferritin level

Deferiprone between 1000 and 1500 μ g/L, when the body iron
Deferoxamine stores are approximately 5 – 10 times normal.
17
However, the serum ferritin correlates poorly with
cardiac iron and is raised in relation to iron status
Myocardial T 2 * (ms) 15 and should therefore be interpreted in conjunction
16
in viral hepatitis and other infl ammatory disorders
with other tests such as T2 * MRI assessment of
cardiac iron, liver biopsy iron (Fig. 4.5 ) and urine
14

deferiprone. The serum ferritin is most useful in
p = 0.023 excretion of iron in response to deferoxamine or
monitoring changes in iron stores because it gives
p = 0.040
13
some indication of whether the stores are falling,

steady or rising. The function of the heart, liver and
p = 0.77
12 endocrine organs are also needed to determine the
Baseline 6 months 12 months

efficacy of chelation therapy (Table 4.3 ).
(a) Deferiprone is an orally active iron chelator
which causes predominantly urinary iron excretion.
74
It is usually given 75 mg/kg in three doses daily. It

Deferiprone
Deferoxamine is licensed in 61 countries but not in the USA or
Canada. It may be used alone or in combination

72 with deferoxamine. The drugs have an additive or
LV ejection fraction (%) 70 is more effective than deferoxamine at removing

even synergistic effect on iron excretion. Deferiprone

cardiac iron (Fig. 4.5 ). Compliance is also better.
Side - effects include an arthropathy, agranulocytosis

(in about 1%), neutropenia, gastrointestinal distur-
68 bance and zinc defi ciency. Monitoring of the blood
count, initially weekly, is needed in all patients
p = 0.074
p = 0.34 p = 0.0034 receiving deferiprone.

®
Deferasirox (Exjade ) is the newest oral chela-

tor. It is given once daily 20 – 40 mg/kg having a
66
Baseline 6 months 12 months prolonged plasma half - life and causes faecal iron
excretion only. Skin rashes and transient changes in
(b)
liver enzymes and a rise in serum creatinine have

Figure 4.5 (a) Reduction in cardiac iron assessed by been reported. The ease of administration and its

T2 * MRI is greater in patients treated with deferiprone lack of major side - effects have resulted in its wide-
than with deferoxamine. (b) Improvement in left spread use.
ventricular (LV) ejection factor is greater with Life expectancy has improved dramatically for
deferiprone than with deferoxamine. (From Pennell thalassaemia major and other transfusion depend-
D.J. et al. (2006) Blood 107 , 3738 – 44, with
ent patients with the introduction of subcutaneous
permission.)
deferoxamine and more recently the two orally

active chelators. There is evidence that they can in
many cases reverse liver and cardiac damage caused
by iron overload, and may also improve endocrine
status (e.g. diabetes mellitus). With good compli-
ance, serious organ damage from iron overload
should be avoided.