Effect of N-acetylcysteine on serum creatinine and kidney function: results of a randomized controlled trial.
BACKGROUND
Evidence for a protective effect of N-acetylcysteine (NAC) on acute and chronic kidney disease is equivocal, and controversy persists about whether NAC affects creatinine level independently of actual kidney function. Study objectives are to investigate whether NAC affects serum creatinine level independently of alterations in other measures of kidney function.


METHODS
Double-blind randomized controlled trial.


METHODS
Patients with stage 3 chronic kidney disease (n = 60), Canada, 2007-2008.


METHODS
Participants were randomly allocated to receive 4 doses of oral NAC (each 1,200 mg) or placebo, administered at 12-hour intervals.


RESULTS
The primary outcome was change in serum creatinine level between baseline and 4 hours after the last treatment dose. In addition, changes in other parameters of kidney function were measured between baseline and 4, 24, or 48 hours after the last treatment dose.


METHODS
Serum creatinine, cystatin C, 24-hour urine protein and creatinine excretion, and creatinine clearance.


RESULTS
60 patients, mean age of 70 years, 75% men, 50% had diabetes, with mean creatinine clearance of 43.7 ± 18.8 (SD) mL/min were enrolled. Between baseline and 4 hours posttreatment, serum creatinine level decreased by 0.044 ± 0.15 mg/dL in the NAC group and 0.040 ± 0.18 mg/dL in the placebo group (95% CI for difference, -0.09 to 0.08; P = 0.9). No significant differences between groups were observed for change in serum creatinine, cystatin C, urine protein, urine creatinine, or creatinine clearance values at any time.


CONCLUSIONS
Blinding patients to orally administered liquid NAC is difficult and it is possible that patients receiving NAC were not sufficiently blinded. Effects of NAC beyond 48 hours of treatment were not evaluated.


CONCLUSIONS
In this randomized controlled trial, NAC had no short-term effect on creatinine level and did not decrease urine protein excretion within 48 hours of treatment.
Moist
Louise
L
Division of Nephrology, Department of Medicine, University of Western Ontario, London, Ontario, Canada. louise.moist@lhsc.on.ca
Sontrop
Jessica M
JM
Gallo
Kerri
K
Mainra
Rahul
R
Cutler
Murray
M
Freeman
Dave
D
House
Andrew A
AA
D000111:Acetylcysteine / Q000627:therapeutic use*; D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000188:drug therapy*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
D055316:Cystatin C; D003404:Creatinine; D000111:Acetylcysteine