title: Comparative investigation of i.v. iohexol and iopamidol: effect on renal function in low-risk outpatients undergoing CT.
abstract: OBJECTIVE
  The purpose of our study was to compare the effects of i.v. iohexol and iopamidol on renal function in outpatients undergoing CT.
  
  
  METHODS
  We performed a prospective, double-blind, randomized clinical trial of 389 adults with low risk for contrast-induced nephropathy, comparing i.v. iohexol with iopamidol (300 mg I/mL). Serum creatinine (SCr) concentration was measured at baseline and 2 and 3 days after contrast administration. A noninferiority analysis was planned to compare the mean maximum SCr change from baseline between subject groups. Contrast-induced nephropathy rates (three definitions) for both contrast agents were compared as a secondary end point.
  
  
  RESULTS
  One hundred ninety and 199 subjects received iohexol and iopamidol, respectively. The mean change in SCr from baseline using the maximum day 2 or 3 measurement was 0.07 ± 0.12 mg/dL (95% CI, 0.05-0.09 mg/dL) for the iohexol group and 0.05 ± 0.12 mg/dL (95% CI, 0.03-0.07 mg/dL) for the iopamidol group. The difference between contrast agents with respect to the mean change in SCr from baseline was -0.02 ± 0.12 mg/dL (95% CI, -0.045 to 0.003 mg/dL; p = 0.08). Contrast-induced nephropathy rates were not statistically different using any definition.
  
  
  CONCLUSIONS
  Although our results were unable to show absolute noninferiority of iohexol compared with iopamidol because of a very small difference in increase in mean SCr from baseline (using a noninferiority margin of 0.04 mg/dL), this difference is likely of minimal or no clinical importance in outpatients undergoing CT with low risk for contrast-induced nephropathy.
authors.affiliation: Department of Radiology, University of Michigan Health System, 1500 E Medical Center Dr, Ann Arbor, MI 48109-5252, USA. jonadill@med.umich.edu
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Dillman
authors.forename: Mahmoud
authors.initials: M
authors.lastname: al-Hawary
authors.forename: James H
authors.initials: JH
authors.lastname: Ellis
authors.forename: Richard H
authors.initials: RH
authors.lastname: Cohan
authors.forename: Ravi
authors.initials: R
authors.lastname: Kaza
authors.forename: James D
authors.initials: JD
authors.lastname: Myles
authors.forename: Shokoufeh
authors.initials: S
authors.lastname: Khalatbari
authors.forename: Isaac R
authors.initials: IR
authors.lastname: Francis
mesh_terms: D016009:Chi-Square Distribution; D003287:Contrast Media / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage*; D007479:Iopamidol / Q000008:administration & dosage*; D007674:Kidney Diseases / Q000139:chemically induced*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007472:Iohexol; D007479:Iopamidol