1001 Intravenous Ferric Carboxymaltose For Restless Legs Syndrome In Children And Adolescents

Abstract

Abstract Introduction Substantial scientific evidence implicates brain iron deficiency in the pathophysiology of restless legs syndrome (RLS). Current clinical guidelines recommend oral and intravenous iron (IV) in the treatment of both adult and pediatric RLS but studies using ferric carboxymaltose (FCM) are lacking in children and adolescents. Methods Retrospective case series of children and adolescents with RLS treated with IV FCM who had serum ferritin levels <50 μg/L. Patients were offered a single dose of IV FCM, 15 mg/kg if weighting <50 kg or 750 mg if weighting >50 kg. Iron profile, serum ferritin, and severity assessment by the International Restless Legs Study Group severity scale (IRLS) were collected pre- and post-infusion. Clinical Global Impression Scale (CGI) was used instead of the IRLS for children. Phosphorus level and adverse effects were assessed post-infusion in all patients. Age and sex-matched children with RLS treated with oral iron supplementation (mean dosage 1.5±0.62 mg/kg/day) were included as a comparison group. Results Twenty-eight subjects (15 females, mean age 11.5 years, SD 4.23) and 24 controls were included. Baseline ferritin levels were not significantly different from those of controls but increased significantly from 13.9±7.02 to 112.9±12.00 μg/L after 8 weeks from infusion (p<0.000001), when they were also significantly higher than control values (34.2±21.64 μg/mL, p<0.000001). Transferrin saturation increased from 22.8±9.77% to 31.7±6.81% (p<0.0001), total iron binding capacity decreased from 366.7±51.32 to 302.0±37.83 μg/dL (p<0.0000035). RLS was reported to be resolved or improved in all children treated with IV iron (vs. 62.5% of controls) while none of them reported no change (vs. 37.5% of controls; Chi-square test 9.84, p<0.002). IRLS Score decreased in adolescents from 30.7±22.68 to 3.2±4.21 (p<0.000008) while CGI-I was “very much improved” in six children and “much improved” in four. Side effects were reported in 17.8% of patients treated IV and 20.8% controls (Chi-square 0.0169, p=0.897). FCM side effects included lightheadedness and gastrointestinal discomfort. Post IV phosphorus levels were normal in all participants. Conclusion This open-label, observational and retrospective study indicates that FCM IV infusion is an effective treatment for pediatric RLS with higher efficacy than oral iron supplementation. Support