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Inadequate response to oral iron therapy

An inadequate response to oral iron therapy may be due to a number of reasons as outlined in the table below with more than one factor often being involved.

Major Reasons for Inadequate Response to Oral Iron Therapy

  • Inadequate iron intake

    • Patient not taking oral iron therapy

    • Patient taking an iron supplement or multivitamin tablet with insufficient iron content

       

  • Inadequate iron absorption:

    • Concomitant consumption of inhibitors of iron absorption (eg, tea, calcium, antacids, tetracycline, within 2 hours of iron ingestion)

    • Coexisting inflammation with functional iron deficiency

    • Intestinal mucosal disorders (eg, coeliac disease, inflammatory bowel disease)

    • Impaired gastric acid secretion (including use of proton pump inhibitors)

    • Gastric/intestinal bypass procedures

    • Helicobacter pylori colonisation

    • Controlled-release iron formulations may contribute (ie, potential for limited iron absorption in some patients)†

       

  • Ongoing iron losses or need in excess of dose absorbed:

    • Occult, undiagnosed or recurrent gastrointestinal blood loss (eg, peptic ulcer, malignancy, angiodysplasia, small bowel lesion, parasites)

    • Other source of recurrent blood loss (eg, menorrhagia due to uterine pathology or an inherited bleeding disorder such as von Willebrand disorder)

    • Multiple sources of recurrent blood loss (eg, hereditary haemorrhagic telangiectasia)

    • Ongoing urinary iron losses (eg, significant valve haemolysis)

    • Renal failure responding to erythropoietin-stimulating agents

       

  • Coexisting condition interfering with bone marrow response:

    • Superimposed infection, inflammation, malignancy or renal failure

    • Concomitant B12 or folate deficiency

    • Coexisting primary bone marrow disease or suppression

       

  • Incorrect diagnosis or more than one cause of anaemia:

     

    • Anaemia of chronic disease or renal failure
    • Haemoglobinopathy
    • Other causes of anaemia (eg, haemolysis, myelodysplastic syndromes, congenital anaemia, endocrine disorders)
* More than one factor is often present. † Role is unclear (limited available data show efficacy comparable to that of non-controlled-release formulations).

Pasricha SR, Flecknoe-Brown SC et al. Diagnosis and management of iron deficiency anaemia: a clinical update. Med J Aust 2010; 193(9): 525-532. © Copyright 2010. The Medical Journal of Australia - reproduced with permission.

References

  1. Pasricha SR, Flecknoe-Brown SC, Allen KJ, Gibson PR, McMahon LP, Olynyk JK, et al. Diagnosis and management of iron deficiency anaemia: a clinical update. MJA 2010;193:525–532. Available from: http://www.mja.com.au.
Updated on 10 July 2012