title: Elimination of intravenously administered ibandronate in patients on haemodialysis: a monocentre open study.
abstract: BACKGROUND
  Ibandronate is an inhibitor of osteoclast-mediated bone resorption. This therapeutic effect is utilized in the treatment of osteoporosis and metastatic bone disease. The effect of ibandronate in patients on haemodialysis with renal osteopathy has not been studied since the pharmacokinetics of ibandronate under haemodialysis are unknown.
  
  
  METHODS
  We analysed the removal of ibandronate from the plasma by haemodialysis in 12 chronic haemodialysis patients suffering from end-stage renal disease (ESRD). After intravenous administration of 1 mg ibandronate, the plasma concentration of ibandronate was determined in plasma samples drawn before entering (inflow) and after passing through (outflow) the haemodialyser, and in the dialysate at 1, 2, 3 and 4 h during the first haemodialysis session, and after 1 and 4 h during the second and third dialysis sessions.
  
  
  RESULTS
  The back-extrapolated initial ibandronate plasma level was 38.9+/-15.9 ng/ml; this decreased during first haemodialysis (after 4 h) to 4.9+/-0.9 ng/ml and after two subsequent haemodialysis treatments to 0.38+/-0.16 ng/ml. Ibandronate concentration was reduced by 47% with every passage through the dialyser. The total decrease of ibandronate plasma concentration during the first 4 h of haemodialysis was 78% of plasma peak levels. The ibandronate dialysis plasma clearance was determined at 92+/-19 ml/min. The total amount excreted at the first dialysis using the recovery rate measure was 364+/-98 microg and using the mean difference in inflow/outflow (arteriovenous) concentration (A-V difference method) it was 371+/-132 microg. About 36% of the total amount of ibandronate administered (1 mg) was removed by the first dialysis treatment.
  
  
  CONCLUSIONS
  Ibandronate was efficiently removed by haemodialysis. After three haemodialysis sessions the ibandronate plasma levels were close to quantification limit. One monthly dose of 1 mg ibandronate would not result in elevated plasma levels in patients with ESRD on haemodialysis treatment three times a week. In haemodialysis patients, ibandronate should be administered after the haemodialysis session.
authors.affiliation: Medizinische Klinik A, Klinikum der Stadt Ludwigshafen GmbH, Ludwigshafen, Germany. bergnerr@klilu.de
authors.forename: Raoul
authors.initials: R
authors.lastname: Bergner
authors.forename: Katja
authors.initials: K
authors.lastname: Dill
authors.forename: Dietmar
authors.initials: D
authors.lastname: Boerner
authors.forename: Michael
authors.initials: M
authors.lastname: Uppenkamp
mesh_terms: D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D001798:Blood Proteins / Q000032:analysis; D001862:Bone Resorption / Q000517:prevention & control*; D004164:Diphosphonates / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D000077557:Ibandronic Acid; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D006435:Renal Dialysis; D012727:Sex Characteristics
chemical_list: D001798:Blood Proteins; D004164:Diphosphonates; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000077557:Ibandronic Acid