title: Pharmacokinetics of 1M gadobutrol in patients with chronic renal failure.
abstract: OBJECTIVE
  To investigate the pharmacokinetics of 1M gadobutrol as a new neutral MR contrast agent in patients with impaired renal function.
  
  
  METHODS
  Twenty-one patients with impaired renal function and any indication for a contrast-enhanced MRI were enrolled into this prospective study and classified in two subgroups according to their creatinine clearance (group 1, 30-80 mL/ min; group 2, 30 mL/min or less, not requiring dialysis). Eleven patients were assigned to the lower dose of 0.1 mmol Gd/kg and 10 patients to the higher dose of 0.3 mmol Gd/kg. To calculate pharmacokinetic parameters, urine and venous blood samples were drawn at baseline and up to 72 hours for group 1 and 120 hours for group 2 after administration of gadobutrol.
  
  
  RESULTS
  The predominant extracellular distribution of gadobutrol at steady state did not change according to the degree of renal impairment. The mean elimination half-life of gadobutrol increased to 7.4 +/- 2.6 hours (0.1 mmol/kg) and 5.4 +/- 1.5 hour (0.3 mmol/kg) in group 1 and to 17.9 +/- 6.2 hours (0.1 mmol/kg) and 20.4 +/- 16.9 hours (0.3 mmol/kg) in group 2, compared with 1.5 hours in healthy volunteers. The relation between serum (tbeta) and urine (t(elim)) elimination half-lives, as well as total serum and renal clearance, indicated renal elimination as the main pathway of elimination. The recovery of gadobutrol in the urine of group 1 was complete within 72 hours for both dosage levels. Patients with severe renal impairment showed a mean recovery of 80.1% (0.1 mmol/kg) and 85.3% (0.3 mmol/kg) within the observation period of 120 hours.
  
  
  CONCLUSIONS
  The half-life of gadobutrol is prolonged in patients with impaired renal function, but elimination by means of the kidneys is the predominant route.
authors.affiliation: Department of Clinical Radiology, University of Münster, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Tombach
authors.forename: C
authors.initials: C
authors.lastname: Bremer
authors.forename: P
authors.initials: P
authors.lastname: Reimer
authors.forename: R M
authors.initials: RM
authors.lastname: Schaefer
authors.forename: W
authors.initials: W
authors.lastname: Ebert
authors.forename: V
authors.initials: V
authors.lastname: Geens
authors.forename: W
authors.initials: W
authors.lastname: Heindel
mesh_terms: D016022:Case-Control Studies; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D005682:Gadolinium; D006207:Half-Life; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D011446:Prospective Studies; D014018:Tissue Distribution
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D005682:Gadolinium