Incidence of hypophosphatemia in patients with inflammatory bowel disease treated with ferric carboxymaltose or iron isomaltoside.

Trond Espen Detlie,Marte Eide Jahnsen,Heinz Zoller,Bjørn Moum,Elisabeth Finnes,Jonas Christoffer Lindstrøm,Jørgen Jahnsen

doi:10.1111/apt.15386

Abstract

Iron deficiency and iron deficiency anaemia are common complications in inflammatory bowel disease (IBD). In patients with moderate-to-severe anaemia, oral iron intolerance or ineffectiveness of oral iron, ferric carboxymaltose and iron isomaltoside are widely used. Hypophosphatemia is a side effect of both preparations. To investigate the occurrence of hypophosphatemia in IBD patients with iron deficiency/iron deficiency anaemia treated with high-dose intravenous iron. A prospective observational study of adult IBD patients with iron deficiency/iron deficiency anaemia was conducted at two study sites where patients received 1000mg of ferric carboxymaltose or iron isomaltoside. At baseline, weeks 2 and 6, blood and faecal samples were collected. The primary endpoint was to determine the incidence of moderate-to-severe hypophosphatemia. Secondary endpoints included the total incidence of hypophosphatemia, possible risk factors for hypophosphatemia, and response to single-dose intravenous iron. One hundred and thirty patients were included. In the per-protocol set, 52 patients received ferric carboxymaltose and 54 patients received iron isomaltoside. Ferric carboxymaltose treatment had a significantly higher incidence of moderate-to-severe hypophosphatemia compared with iron isomaltoside at week 2 (56.9% vs 5.7%, P<0.001) and a higher incidence at week 6 (13.7% vs 1.9%, P=0.054).The overall incidence of hypophosphatemia was significantly higher with ferric carboxymaltose compared with iron isomaltoside treatment at weeks 2 (72.5% vs 11.3%, P<0.001) and 6 (21.6% vs 3.7%, P=0.013). In IBD patients with iron deficiency/iron deficiency anaemia, ferric carboxymaltose was associated with higher incidence, severity and persistence of hypophosphatemia compared with iron isomaltoside. The presence of moderate-to-severe hypophosphatemia beyond 6weeks is a clinical concern that requires further investigation.

Highlights

Anaemia is a frequent complication of inflammatory bowel disease (IBD).[1]
The aim of this study was to investigate the rate of hypophosphate‐ mia after infusion of a single dose of intravenous iron (1000 mg) in adults with IBD treated with either ferric carboxymaltose or iron isomaltoside
With respect to the primary endpoint, at week 2, 56.9% of pa‐ tients treated with ferric carboxymaltose experienced moderate to severe hypophosphatemia after a single 1000 mg dose com‐ pared with 5.7% of the patients treated with iron isomaltoside (P < 0.001)

Summary

Introduction

Anaemia is a frequent complication of inflammatory bowel disease (IBD).[1]. In adults with IBD, the prevalence of anaemia is approximately 60% at the time of diagnosis and approximately 30%‐40% at any other time.[1,2] Iron deficiency has been identified as a major cause of anaemia.[1]. Iron deficiency and iron deficiency anaemia have been found to recur after therapy with intravenous iron in IBD patients (median 19 months for iron deficiency and 10 months for iron deficiency anaemia), indicating a need for repeated infusions.[5]

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