title: Proximal muscular atrophy and weakness: An unusual adverse effect of deferasirox iron chelation therapy.
abstract: Deferasirox is a standard treatment for chronic transfusional iron overload. Adverse effects of deferasirox have been reported in large prospective studies. We report two cases of monozygotic twins manifesting with proximal muscular atrophy and weakness under deferasirox. Discontinuation of deferasirox resulted in symptom improvement and ultimately in complete remission five months after successful haematopoietic stem cell transplantation. Broad diagnostic work-up could not bring evidence of another aetiology of muscular weakness. Iron overload or beta thalassemia itself as a cause is considered unlikely in our patients because the chronological coincidence of muscular symptoms was contra-directional to serum ferritin levels and significant clinical improvement was observed promptly after cessation of deferasirox even before transplantation. These observations suggest that the development of muscular weakness in patients on deferasirox should be recognised as a possible adverse effect of the drug.
authors.affiliation: Department of Pediatric Neurology and Developmental Medicine, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany. Electronic address: katharina.vill@med.uni-muenchen.de.
authors.forename: K
authors.initials: K
authors.lastname: Vill
authors.affiliation: Department of Pediatric Neurology and Developmental Medicine, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Müller-Felber
authors.affiliation: Department of Pediatric Radiology, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Teusch
authors.affiliation: Department of Pediatric Neurology and Developmental Medicine, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Blaschek
authors.affiliation: Department of Pediatric Neurology and Developmental Medicine, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Gerstl
authors.affiliation: Department of Pediatric Hematology and Oncology, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Huetker
authors.affiliation: Department of Pediatric Hematology and Oncology, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: M H
authors.initials: MH
authors.lastname: Albert
mesh_terms: D001565:Benzoates / Q000009:adverse effects* / Q000627:therapeutic use; D015913:Chelation Therapy / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D000077588:Deferasirox; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007501:Iron; D007502:Iron Chelating Agents / Q000009:adverse effects* / Q000627:therapeutic use; D018908:Muscle Weakness / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D009133:Muscular Atrophy / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D014184:Transplantation, Homologous; D014230:Triazoles / Q000009:adverse effects* / Q000627:therapeutic use; D014430:Twins, Monozygotic; D017086:beta-Thalassemia / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology
chemical_list: D001565:Benzoates; D007502:Iron Chelating Agents; D014230:Triazoles; D007501:Iron; D000077588:Deferasirox
keywords: Adverse effects; Beta-thalassemia major; Deferasirox; Iron chelation therapy; Muscular weakness