title: Response to intravenous iron in patients with iron deficiency anemia (IDA) and restless leg syndrome (Willis-Ekbom disease).
abstract: OBJECTIVE
  Iron deficiency anemia (IDA) engenders restless legs syndrome (RLS, aka Willis-Ekbom disease). Intravenous (IV) iron can rapidly reverse IDA and would be expected to similarly reverse RLS caused by IDA. This is the first consecutive case series evaluating the effects of IV iron therapy on RLS occurring with IDA (RLS-IDA).
  
  
  METHODS
  RLS-IDA patients were evaluated before and 7-12 months after a 1000-mg IV infusion of low-molecular-weight iron dextran (INFeD(@)) using validated questionnaires and standardized telephone interview. Patients were classified as respondent versus nonrespondent for RLS improvement.
  
  
  RESULTS
  Follow-up data were obtained on 42 (70%) of 60 consecutive RLS-IDA patients. The symptoms of RLS were reduced in 76% (32/42) with 47% (20/42) showing an extended response lasting >6 months. The response did not relate to age or gender, but tended to be less among African-Americans than Whites (40% (2/5) vs. 81% (30/37), p = 0.078). White respondents versus nonrespondents had higher hemoglobin levels after treatment (12.1 vs. 11.3 g/dl, p = 0.03).
  
  
  CONCLUSIONS
  RLS-IDA is reduced after administration of IV iron in most cases, but the 24% failing to respond was higher than expected. The nonrespondents all showed below-normal hemoglobin levels (<12.5 g/dl) suggesting a failure of adequate treatment of the iron deficiency. IV iron treatment of the RLS with IDA likely requires ensuring more than minimally adequate body iron stores to support iron delivery to the brain. For some, this may require a dose higher than the customary 1000-mg IV iron used for the treatment of either IDA or RLS alone.
authors.affiliation: Division of Transfusion Medicine, Department Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Tahir
authors.initials: T
authors.lastname: Mehmood
authors.affiliation: Department of Medicine, Georgetown University, Washington DC, USA; Private Practice, Baltimore, MD, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Auerbach
authors.affiliation: Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Earley
authors.affiliation: Department of Neurology, Johns Hopkins University, Baltimore, MD, USA. Electronic address: richardjhu@mac.com.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Allen
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000150:complications* / Q000188:drug therapy; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007505:Iron-Dextran Complex / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012148:Restless Legs Syndrome / Q000188:drug therapy / Q000209:etiology*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D007505:Iron-Dextran Complex
keywords: INFeD; IV iron; Iron deficiency anemia; Low-molecular-weight dextran; Restless legs syndrome (RLS); Sleep; Willis–Ekbom disease (WED)