title: Hydroxyurea therapy associated with declining serum levels of magnesium in children with sickle cell anemia.
abstract: OBJECTIVE
  To obtain quantitative serum levels of total and ionized magnesium (Mg(2+)) in children with homozygous sickle cell anemia (SCA) undergoing therapy with hydroxyurea.
  
  
  METHODS
  Five children, ages 11 to 14 years with homozygous SCA, were enrolled in a dose-escalating trial of hydroxyurea over an 18-month period. Serum levels of total and ionized magnesium together with ionized K(+), Na(+), and Ca(2+) were measured before hydroxyurea and every 6 months during hydroxyurea therapy.
  
  
  RESULTS
  Before treatment, 4 of the 5 patients had low or below-normal serum concentrations of Mg(2+) (normal range, 0.51-0.67 mmol/L). All 5 became Mg(2+)-deficient during hydroxyurea therapy, with no indication of recovery until after 12 to 18 months of drug administration (P <.05). Similar changes were noted for total magnesium concentrations. Mean serum levels of K(+), Na(+), and Ca(2+) remained consistently within normal ranges.
  
  
  CONCLUSIONS
  These findings warrant a controlled study of the effects of magnesium supplementation in patients with SCA receiving hydroxyurea. Potentially, such therapy could alleviate or prevent vaso-occlusive crises.
authors.affiliation: Division of Hematology-Oncology, Columbus Children's Hospital and Ohio State University, 43205, USA.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Altura
authors.forename: Winfred C
authors.initials: WC
authors.lastname: Wang
authors.forename: Lynn
authors.initials: L
authors.lastname: Wynn
authors.forename: Burton M
authors.initials: BM
authors.lastname: Altura
authors.forename: Bella T
authors.initials: BT
authors.lastname: Altura
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D000755:Anemia, Sickle Cell / Q000188:drug therapy*; D000986:Antisickling Agents / Q000008:administration & dosage / Q000009:adverse effects*; D002648:Child; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006918:Hydroxyurea / Q000008:administration & dosage / Q000009:adverse effects*; D008275:Magnesium Deficiency / Q000139:chemically induced*; D008297:Male; D010865:Pilot Projects; D013997:Time Factors
chemical_list: D000986:Antisickling Agents; D006918:Hydroxyurea