title: Comparison of dietary phosphate absorption after single doses of lanthanum carbonate and sevelamer carbonate in healthy volunteers: a balance study.
abstract: BACKGROUND
  Lanthanum carbonate and sevelamer carbonate are noncalcium phosphate binders used to treat hyperphosphatemia in patients with chronic kidney disease. This is the first study to compare phosphate absorption from a standardized meal ingested with a typical clinical dose of these binders.
  
  
  METHODS
  Randomized open-label crossover study.
  
  
  METHODS
  Healthy volunteers were confined to a clinical research center during 4 study periods. Of 31 volunteers randomly assigned, 19 completed all treatments and 18 were analyzed in the pharmacodynamic set (1 was excluded because of vomiting).
  
  
  METHODS
  Participants were assigned in random order to meal alone, meal plus lanthanum carbonate (1 tablet containing 1,000 mg of elemental lanthanum), and meal plus sevelamer carbonate (three 800-mg tablets). The gastrointestinal tract was cleared, the meal was ingested (± treatment), and rectal effluent was collected. In a fourth period, volunteers repeated the study procedures while fasting.
  
  
  RESULTS
  The primary end point, net phosphate absorption, was analyzed using a mixed-effect linear model.
  
  
  METHODS
  Phosphorus content of effluent and duplicate meal samples were measured using inductively coupled plasma-optical emission spectroscopy.
  
  
  RESULTS
  The standard meal contained ∼375 mg of phosphate, 75% of which was absorbed (net absorption, 281.7 ± 14.1 mg [adjusted mean ± standard error]). Lanthanum carbonate decreased net phosphate absorption by 45% (net absorption, 156.0 ± 14.2 mg) compared with 21% (net absorption, 221.8 ± 14.1 mg) for sevelamer carbonate (P < 0.001). Lanthanum carbonate bound 135.1 ± 12.3 mg of phosphate, whereas sevelamer carbonate bound 63.2 ± 12.3 mg, a 71.9-mg difference (95% CI, 40.0-103.8; P < 0.001). Per tablet, this equates to 135 mg of phosphate bound with lanthanum carbonate versus 21 mg with sevelamer carbonate.
  
  
  CONCLUSIONS
  A single-dose study.
  
  
  CONCLUSIONS
  In healthy volunteers, 1,000 mg of lanthanum carbonate decreased phosphate absorption by 45% compared with a 21% decrease with 2,400 mg of sevelamer carbonate.
authors.affiliation: Shire Pharmaceuticals, Wayne, PA 19087-5637, USA. pmartin@shire.com
authors.forename: Patrick
authors.initials: P
authors.lastname: Martin
authors.forename: Phillip
authors.initials: P
authors.lastname: Wang
authors.forename: Antoine
authors.initials: A
authors.lastname: Robinson
authors.forename: Lynne
authors.initials: L
authors.lastname: Poole
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Dragone
authors.forename: Michael
authors.initials: M
authors.lastname: Smyth
authors.forename: Raymond
authors.initials: R
authors.lastname: Pratt
mesh_terms: D000328:Adult; D002614:Chelating Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology*; D007811:Lanthanum / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D016226:Phosphorus, Dietary / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011073:Polyamines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000069603:Sevelamer; D055815:Young Adult
chemical_list: D002614:Chelating Agents; D016226:Phosphorus, Dietary; D011073:Polyamines; C119467:lanthanum carbonate; D007811:Lanthanum; D000069603:Sevelamer