Intravenous Low Molecular Weight Iron Dextran (LMWID) in the Treatment of Children with Iron Deficiency Anemia,

While iron deficiency anemia (IDA) is among the most common hematologic disorders during childhood, management strategies for patients poorly responsive to oral iron therapy have not been well studied. Children treated for IDA often have a poor response to oral iron due to noncompliance, intolerance of side effects, malabsorption, ongoing blood loss, or a combination of these factors. Alternative treatment approaches are therefore needed. Intravenous (IV) iron, including low molecular weight iron dextran (LMWID), offers the possibility of correcting the anemia and repleting iron stores using a single dose, potentially decreasing the overall burden of treatment. Use of LMWID in children has been limited due to concerns about anaphylaxis associated with high molecular weight iron dextran preparations, even though in adults the risk of anaphylaxis is decreased when alternative IV iron preparations, including LMWID, are employed. In this study we report our initial experience with LMWID in children with IDA.

We performed a retrospective record review of patients receiving IV LMWID for IDA in the Center for Cancer and Blood Disorders at Children's Medical Center Dallas between December 1, 2010 and July 31, 2011. Records were reviewed for age, indication for LMWID, concurrent medical problems, use of premedication, initial and follow-up hemoglobin values, adverse events (AEs), and prior or subsequent receipt of other IV iron preparations. The primary study aim was to characterize the clinical course of patients receiving LMWID to inform a planned prospective cohort study of IV iron in children with IDA poorly responsive to oral iron therapy.

A total of 18 patients, age 11 months (mos) to 18 years (yrs), received IV LMWID during the study period. 11 of them (median age 13 yrs) received LMWID for IDA secondary to external blood loss due to menorrhagia (n=3), gastrointestinal disease (n=3), hemophilia (n=2), Von Willebrand disease (n=2), and immune thrombocytopenia (n=1). Five (median age 2 yrs) had IDA due to nutritional deficiency, and two patients had multiple causes for their IDA.

14 patients (77.8%) received their initial LMWID infusion without AEs, and all demonstrated an increase in hemoglobin (mean 3 g/dL) 4 to 7 weeks following infusion. Premedication with diphenhydramine, acetaminophen, hydrocortisone, or a combination of these was given to 6 of the 14 patients (42.8%) at the discretion of the treating physician based on history of atopy. The average dose of LMWID was 600 mg (20.2mg/kg) with a range of 150 mg to 1 gram (6.9 mg/kg to 30.9 mg/kg). 3 of these 14 patients (21.4%) required a subsequent infusion to achieve and maintain a normal hemoglobin due to ongoing blood loss.

6 patients (33.3%) had transient AEs during LMWID infusion including hives (n=3), tachycardia (n=2), chest tightness (n=1), fever (n=2), nausea (n=1), vomiting (n=1), sweating (n=2), and cough (n=1). 2 of them were able to complete the infusion without further sequelae after receiving diphenhydramine or hydrocortisone. Only one of the patients with AEs had received premedication, although on review 3 of the 6 patients with AEs had a concurrent medical problem affecting immune function including asthma and orthotopic liver transplant. No patient required hospital admission or treatment of the AE beyond the day of their clinic visit. 4 of the 6 patients with AEs related to LMWID subsequently received IV iron sucrose infusions without any complications.

Among 18 children with IDA receiving LMWID planned as a single dose infusion, treatment was well tolerated and effective in 14 of them and associated with only transient AEs in 6. The latter patients were able to either receive the remainder of the LMWID infusion or an alternative iron preparation without complication. Some patients with ongoing blood loss needed additional infusions, although the majority of children were treated effectively with a single dose. These encouraging results support the need for further study of LMWID in children with IDA unresponsive to oral iron therapy or even as an initial treatment alternative to the oral route.

No relevant conflicts of interest to declare.