title: Placebo-controlled study of intravenous magnesium supplementation during large-volume leukapheresis in healthy allogeneic donors.
abstract: BACKGROUND
  Marked decreases in ionized magnesium (iMg) levels occur during large-volume leukapheresis (LVL); however, the effect of intravenous (IV) magnesium supplementation in this setting has not been carefully studied.
  
  
  METHODS
  Thirty healthy allogeneic peripheral blood progenitor cell donors receiving citrate anticoagulant with IV calcium prophylaxis were randomized to receive either IV magnesium (0.2 mg Mg per mL acid citrate dextrose-A) or placebo during LVL, with a double-blind design.
  
  
  RESULTS
  Thirty subjects underwent 75 LVL pro- cedures, 37 with magnesium and 38 with placebo. Group characteristics were similar for sex, weight, citrate infusion rate (1.36 mg/kg/min vs. 1.37 mg/kg/min), and volume processed (16 L vs. 17 L). Serum iMg levels remained within the reference range with magnesium supplementation, but decreased 39+/-11 percent below baseline (p<10(-10)) after placebo, with greater decreases after consecutive procedures. Subjects receiving magnesium had more vigorous parathyroid hormone responses and higher glucose levels and also tended to have higher serum potassium and ionized calcium levels. Mild paresthesias, coldness, and nausea occurred in 28, 20, and 7 percent of donors, respectively, with no significant differences between groups. Severe symptoms (chest tightness) occurred in only one subject receiving placebo.
  
  
  CONCLUSIONS
  IV magnesium supplementation exerts a significant impact on serum magnesium levels, but does not reduce the frequency or severity of the relatively mild citrate-related effects observed in LVL performed with continuous IV calcium prophylaxis.
authors.affiliation: Department of Transfusion Medicine, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA. salim.haddad@Fda.hhs.gov
authors.forename: Salim
authors.initials: S
authors.lastname: Haddad
authors.forename: Susan F
authors.initials: SF
authors.lastname: Leitman
authors.forename: Robert A
authors.initials: RA
authors.lastname: Wesley
authors.forename: Stacey
authors.initials: S
authors.lastname: Cecco
authors.forename: Yu Ying
authors.initials: YY
authors.lastname: Yau
authors.forename: Judith
authors.initials: J
authors.lastname: Starling
authors.forename: Nadja N
authors.initials: NN
authors.lastname: Rehak
authors.forename: Charles D
authors.initials: CD
authors.lastname: Bolan
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects; D001782:Blood Donors; D001810:Blood Volume; D002118:Calcium / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D019343:Citric Acid / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D003404:Creatinine / Q000652:urine; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007262:Infusions, Intravenous; D007937:Leukapheresis / Q000379:methods*; D008274:Magnesium / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010292:Paresthesia / Q000139:chemically induced; D010919:Placebos; D011188:Potassium / Q000097:blood; D011446:Prospective Studies; D012996:Solutions; D013997:Time Factors; D014184:Transplantation, Homologous
chemical_list: D000925:Anticoagulants; D010281:Parathyroid Hormone; D010919:Placebos; D012996:Solutions; D019343:Citric Acid; D003404:Creatinine; D008274:Magnesium; D011188:Potassium; D002118:Calcium