Blood Disorders

Question 1

Which statement about iron supplementation is FALSE?
a) Iron is poorly absorbed from enteric-coated tablets
b) The dosing of iron supplementation is slowly increased to minimize gastric upset
c) Elemental iron has few drug interactions
d) The target daily dose of elemental iron is 105-200mg per day
e) An equivalent strength of ferrous fumarate provides more elemental iron than ferrous gluconate

Answer 1

C. Oral iron preparations have many drug interactions, usually due to chelation. This reduces the absorption of both agents in the interaction and their administration should be separated by approximately 2 hours. Nonenteric-coated salts are preferred due to concerns with the effectiveness of enteric-coated preparations in releasing iron in the gastric environment. Gastrointestinal side effects are the main reasons for non-adherence and a graduated approach to dosing should be used to minimize these. The target daily dose is 105-200mg of elemental iron per day although in the elderly 15-50mg per day may be sufficient (page 1206, CTC, 7th edn). A 300mg tablet of ferrous fumarate provides 100mg of elemental iron; an equivalent tablet of ferrous gluconate provides only 35mg (Table 1, page 1213, CTC, 7th edn).

Question 2

What is anemia?

Answer 2

a condition in which the number of red blood cells (and consequently oxygen-carrying capacity) is insufficient to meet the body’s physiologic needs.

Question 3

What anemias respond to drugs?

Answer 3

• anemias due to iron, vit B12, folate deficiency
• anemias responding to erythropoietin therapy

Question 4

Goals of therapy
Anemia

Answer 4

• alleviate symptoms
• restore normal or adequate Hb level
• improve quality of life
• prolong survival

Question 5

According to WHO, when is anemia diagnosed using Hb levels?

Answer 5

men: <130 g/L
women (non-pregnant): <130 g/L

Question 6

Investigations
Anemia

Answer 6

• hx for bleeding, jaundice, GI sx, heavy menses, family hx of anemia, medication use, diet, alcohol, comorbid conditions
• PE
• underlying causes: Deficiency in diet, conditions related to malabsorption, blood loss, LV dz/alcohol use, inherited defects in hemoglobin, suppression of bone marrow, def of erythropoeitin due to chronic kd dz or comorbind conditions (like hypothyroidism), chronic inflammatory diseases
• CBC: MCV (red cell size - too small <80 fL), RBCs. Peripheral blood smear. Ferritin, transferrin, vitamin b12.

Question 7

How iron def anemia presents?

Answer 7

low MCV
low ferritin
low Hb
low transferrin sat
high transferrin
low hepcidin

Question 8

How anemia of chronic disease presents?

Answer 8

high ferritin
high CRP
low to normal MCV
low Hb
low to normal transferrin sat
low to normal transferrin

Question 9

How anemia of chronic disease and iron deficiency anemia present together?

Answer 9

high CRP
low Hb
normal to high ferritin
low to normal transferrin sat
low transferrin
low MCV