Iron Overload

Question 1

Severe tissue iron overload can occur in aplastic and other refractory anaemias, mainly as the result of ______________

Answer 1

repeated blood transfusions

Question 2

Severe tissue iron overload can occur in _________________, mainly as the result of repeated blood transfusions

Answer 2

aplastic and other refractory anaemias

Question 3

Iron overload is a particular problem in refractory anaemias with ______________ bone marrow, especially thalassaemia major, where excessive iron absorption from the gut and inappropriate iron therapy can add to the tissue siderosis

Answer 3

hyperplastic

Question 4

It is a particular problem in refractory anaemias with hyperplastic bone marrow, especially ________________, where excessive iron absorption from the gut and inappropriate iron therapy can add to the tissue siderosis

Answer 4

thalassaemia major

Question 5

Iron overload associated with haemochromatosis can be treated with ________________

Answer 5

repeated venesection

• Venesection may also be used for patients who have received multiple transfusions and whose bone marrow has recovered

Question 6

Where venesection is contra-indicated, the long-term administration of the ___________________ is useful

Answer 6

iron chelating compound desferrioxamine mesilate

Question 7

Desferrioxamine mesilate (up to 2 g per unit of blood) may also be given at the time of blood transfusion, provided that the desferrioxamine mesilate is not ______________ and is not _________________

Answer 7

added to the blood

given through the same line as the blood (but the two may be given through the same cannula)

Question 8

Iron excretion induced by desferrioxamine mesilate is enhanced by administration of ______________ daily by mouth

Answer 8

ascorbic acid (vitamin C)

• it should be given separately from food since it also enhances iron absorption

Question 9

Ascorbic acid should not be given to patients with ______________

Answer 9

cardiac dysfunction

Question 10

In patients with normal cardiac function ascorbic acid should be introduced ____________ after starting desferrioxamine mesilate

Answer 10

1 month

Question 11

Desferrioxamine mesilate infusion can be used to treat ________________ in dialysis patients

Answer 11

aluminium overload

• theoretically 100 mg of desferrioxamine binds with 4.1 mg of aluminium

Question 12

Desferrioxamine should be prescribed with caution in which patients?

Answer 12

Patients with aluminum-related encephalopathy (may exacerbation neurological dysfunction)

Question 13

What are the common or very common side effects of desferrioxamine? (7)

Answer 13

1. Arthralgia and muscle complaints
2. Bone disorder
3. Fever
4. Growth retardation
5. Headache
6. Nausea
7. Skin reactions

Question 14

Is desferrioxamine safe to use in pregnancy and breastfeeding?

Answer 14

Teratogenic in animal studies; use only if potential benefits outweigh risks

Question 15

Is desferrioxamine safe to use in hepatic and/or renal impairment?

Answer 15

Use with caution in renal impairment

Question 16

What are the monitoring requirements of patients taking desferrioxamine?

Answer 16

Eye and ear examinations before treatment and at 3-month intervals during treatment

(Due to rare side effects of vision loss and neurosensory deafness)

Question 17

What are the uncommon or rare side effects of desferrioxamine? (16)

Answer 17

1. Angioedema
2. Blood disorder
3. Cataracts, eye disorders
4. Diarrhea, vomiting
5. Dizziness
6. Encephalopathy
7. Hypresensitivity
8. Hypotension (common when given too rapidly by IV)
9. Increased risk of infection
10. Nerve disorders, paresthesia
11. Respiratory disorders
12. Shock
13. Tachycardia
14. Thrombocytopenia
15. Asthma
16. Neurosensory deafness, tinnitus

Question 18

It is rarely necessary to prescribe more than __________ mg of ascorbic acid daily except early in the treatment of scurvy

Answer 18

100

Question 19

It is rarely necessary to prescribe more than 100 mg of ascorbic acid daily except early in the treatment of ___________

Answer 19

scurvy

Question 20

Ascorbic acid is contraindicated in patients with ____________

Answer 20

Hyperoxaluria