revised April 25, 1997
Iron and Thalassemia
Thalassemia and iron metabolism are closely linked. Iron deficiency and
mild forms of thalassemia (e.g., thalassemia trait) are often confused.
Both are associated with mild to moderate anemia and microcytosis (small
red cells). At the other end of the spectrum, severe forms of thalassemia
frequently produce iron overload. Excess iron accumulates due to enhanced
iron absorption produced by thalassemia, repeated blood transfusions or
both. A number of questions are frequently asked regarding thalassemia and
iron.
- Should a person with thalassemia trait avoid iron, such as iron-fortified
vitamins?
Iron replacement tablets or iron-supplemented vitamins should be taken only
as directed by a physician to treat actual iron deficiency or to prevent
iron deficiency in high risk circumstances (e.g., pregnancy). People with
thalassemia trait (thalassemia minor) are not per se at greater risk of
complications from iron in the diet than anyone else in the general population.
There are instances, however, in which coincident conditions can increase
the risk of iron overload. For example, people with thalassemia trait who
also inherit the gene for hereditary hemochromatosis can accumulate dangerous
levels of iron by using dietary iron supplements.
- Can the anemia produced by thalassemia be corrected or improved by
taking more iron?
In the absence of concomitant iron deficiency, iron supplementation will
neither correct nor improve anemia due to thalassemia. For people with both
iron deficiency and thalassemia, iron replacement will lessen the severity
of the anemia, until the iron deficiency is corrected. The blood count will
level off and no further improvement will occur.
- What is the best treatment for a person with severe thalassemia (thalassemia
major or thalassemia intermedia) who accumulates too much iron?
Excess iron accumulation a leading cause of clinical deterioration and often
death in patients with severe forms of thalassemia. The excess iron can
be removed from the patient's body only by iron-binding drugs called chelators.
The most widely used chelator is desferrioxamine, whose trade name is Desferal®.
This medication can prevent many of the complications associated with iron
overload. The drug is most effective when given daily over periods of time
ranging from 12 to 16 hours. A special pump that the patient wears slowly
gives the medication under the skin. Desferal®
has been given as an intravenous infusion at the time of blood transfusion.
This method of delivery does not effectively remove iron. Desferal®
is not effective when given by mouth. A new oral agent called deferipone
or L1 continues to be tested in people. The drug effectively removes iron
from many patients with substantial iron overload. The key unknown with
this agent is its safety.
