Efficacy and tolerability of intravenous iron dextran and oral iron in inflammatory bowel disease: a case-matched study in clinical practice.

OBJECTIVES: Iron deficiency anaemia is common in inflammatory bowel disease (IBD); however, the optimum route of administration of iron replacement therapy is unclear. As inflammation may limit the absorption and efficacy of oral iron, we hypothesized that in routine clinical practice IV iron would be more effective than oral iron in patients with IBD matched for disease type, extent and activity. METHODS: Thirty-three IBD patients who had received IV iron dextran (Cosmofer) in 2008-2010 were identified and matched for age, sex, diagnosis and baseline disease activity, extent and behaviour to IBD patients given oral iron. RESULTS: Patients given IV iron dextran were more anaemic at baseline than those receiving oral iron. Although haemoglobin (Hb) concentrations were normalized in about a third of patients, and increased significantly in both groups, the mean increase in Hb after 8 weeks was greater in the iron dextran group [2.0 g/dl (0.3) vs. 0.6 g/dl (0.1), P<0.0001]. Response to oral or IV iron was unrelated to age, sex, ethnicity, disease duration, extent or activity. Fifteen percent (five out of 33) patients discontinued oral iron because of gastrointestinal side-effects and a further two out of 35 had anaphylactoid reactions to the IV iron dextran test doses. Neither of the iron formulations worsened disease activity. CONCLUSION: In routine clinical practice, in anaemic patients with IBD of similar type, extent and activity, IV Cosmofer is more efficacious in increasing Hb concentration than oral iron. Active disease does not impair the response to either IV or oral iron in patients with IBD, and neither product itself worsens disease activity.