Ferric carboxymaltose treatment for iron deficiency anemia in children with inflammatory bowel disease: Efficacy and risk of hypophosphatemia.

Background: Although intravenous ferric carboxymaltose (FCM) is effective in treating iron deficiency anemia (IDA) in paediatric inflammatory bowel disease (pIBD), no data are available on its post-infusion related risks.

Aims: We assessed the efficacy of FCM and the rate of post-infusion hypophosphatemia in a large cohort of children with IBD and IDA.

Methods: All children with IBD with IDA treated with FCM over 5-year period were reviewed. Disease activity, biohumoral assessment and treatments were evaluated at baseline, 4-6 and 12 weeks after each infusion.

Results: 128 patients [median age at first infusion: 13 years] were identified, 81 (63.3%) were <14 years, 10 (7.8%) <6 years. Eighty-three children (64.8%) received one infusion, whilst 45 (35.2%) repeated infusions. A significant increase in Hb (p<0.001), iron (p<0.001) and ferritin (p<0.001) was observed 4-6 and 12 weeks post-infusion. Hb gain was unrelated to disease severity. Low baseline iron was the main predicting factor for repeated infusions (p<0.05). Three patients reported infusion reactions, none <6 years. Twenty-five children had low post-infusion serum phosphate (11 were <14 years, 3 <6 years). Two children developed severe hypophosphatemia.

Conclusions: FCM administration is effective for IDA management in pIBD, including children <6 years. Due to the high prevalence of post-infusion hypophosphatemia, serum phosphate monitoring should be mandatory.