Efficacy and safety of high-dose intravenous iron as the first-choice therapy in outpatients with severe iron deficiency anemia.

Background: Asymptomatic severe iron deficiency anemia is a common finding in subjects admitted to the outpatient anemia clinic. Although the condition can be easily be reversed with intravenous iron (IVI) therapy and several guidelines have suggested a restrictive threshold for using transfusion in hemodynamically stable patients, transfusion is often the rule in clinical practice. This study describes clinical practice results of IVI therapy without transfusion.

Study Design And Methods: In this multicenter retrospective observational study, data of severely anemic outpatients treated only with high-dose IVI with ferric carboxymaltose were collected. Inclusion criteria were hemoglobin (Hb) level of less than 7.0 g/dL and ferritin level of less than 30 ng/mL or mean corpuscular volume of less than 75 fL.

Results: Overall, 303 patients referred to the anemia clinic mainly from primary health care centers (46.2%) or the emergency department (28.7%) met the inclusion criteria. Median (interquartile range [IQR]) age was 47 (37-62) years and 84.5% were female. The median (IQR) Hb concentration at first visit was 6.5 (6.1-6.8) g/dL, 64 patients (21.1%) presented with a Hb level of less than 6.0 g/dL at diagnosis, and 11 of them (3.6%) had extreme anemia (Hb ≤ 5 g/dL). Gynecologic and gastroenteric bleeding were the main cause. After a mean IV administration of 1500 mg of iron, the Hb increased by a median of 5.7 g/dL. Thirteen patients experienced only mild side effects.

Conclusions: In chronic very severe sideropenic anemias, third-generation IVI is effective and safe for quick correction and avoidance of red blood cell transfusion. These results suggest that more specific guidelines for this clinical setting are warranted.