Effect of N-acetylcysteine on renal function in patients with chronic kidney disease

BACKGROUND: N-acetylcysteine (NAC) is commonly administered to high-risk individuals to attenuate the risk of contrast-induced nephropathy in spite of the debate regarding its efficacy. In several studies serum creatinine decreased after exposure to NAC and contrast dye. The mechanism by which NAC attenuates the decline in renal function is not known. Studies in subjects with normal renal function suggest NAC may have an effect on tubular secretion. AIM: The aim of this study was to determine the effect of NAC on renal function, measured by serum creatinine and Cystatin C, in patients with stage 3 chronic kidney disease. METHOD: Serum creatinine and Cystatin C were measured prior to, 4, 24 and 48 h after the administration of 600 mg oral NAC in 30 patients. The protocol was repeated with the addition of 1200 mg oral cimetidine administered 3 h before NAC. RESULTs: Serum creatinine was not significantly different from baseline (186 +/- 65 micromol/L) to 4 h (185 +/- 62 micromol/L), 24 h (187 +/- 64 micromol/L) or 48 h (184 +/- 61 micromol/L) post NAC, nor were Cystatin C levels. Co-administration of cimetidine resulted in a significant rise in serum creatinine with no change in Cystatin C levels. CONCLUSION: This study failed to detect a change in serum creatinine or Cystatin C after a single dose of NAC in participants with stage 3 chronic kidney disease. Further randomized trials of multiple doses and longer follow up are needed to confirm these results.