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).