N-Acetylcysteine does not artifactually lower plasma creatinine concentration

Michael Haase, Anja Haase-Fielitz, Sujiva Ratnaike, Michael C. Reade, Sean M. Bagshaw, Stanislao Morgera, Duska Dragun, Rinaldo Bellomo

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Background. All randomized controlled trials of N-acetylcysteine (NAC) in contrast media-induced nephropathy used creatinine as a marker of renal function. However, it has been suggested that NAC may lower plasma creatinine levels independent of any effects on glomerular filtration rate (GFR). Methods. At a tertiary hospital 110 cardiac surgical patients were randomly allocated to peri-operative infusion of NAC (300 mg/kg over 24 h, N = 30) or placebo (N = 80). We compared the plasma concentrations of creatinine, cystatin C and urea, the plasma creatinine/plasma cystatin C ratio and the estimated GFR at baseline and at 24 and 72 h after commencement of the infusion. We measured urinary creatinine concentration at 24 h. Results. At baseline, the plasma creatinine/plasma cystatin C ratio did not differ between the NAC and placebo group (0.90 versus 0.92; P = 0.94). There was no significant difference in the plasma creatinine/plasma cystatin C ratio for the NAC and placebo group either during or after NAC infusion at 24 h (1.03 versus 1.00; P = 0.78) and 72 h (0.94 versus 0.89; P = 0.09). Those allocated to NAC showed no difference in urinary creatinine excretion when compared to placebo (P = 0.24). Conclusions. The results of our study do not demonstrate that NAC artifactually lowers creatinine measured using the Jaffé method. (ClinicalTrials.gov, NCT00332631, NCT00334191).

Original languageEnglish
Pages (from-to)1581-1587
Number of pages7
JournalNephrology Dialysis Transplantation
Issue number5
Publication statusPublished - 1 May 2008


  • Acute kidney injury
  • Contrast-induced nephropathy
  • Creatinine
  • Cystatin C
  • N-acetylcysteine

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