The role of N-acetylcysteine in preventing radiographic contrast-induced nephropathy.

INTRODUCTION: There have been many small randomized controlled trials evaluating the effectiveness of N-acetylcysteine (NAC) in preventing radiographic contrast-induced nephropathy. Most studies have suggested a beneficial NAC effect. This meta-analysis describes the effect of NAC in the prevention of radiographic contrast-induced nephropathy in the aggregated trial data. METHODS: A search using MEDLINE from 1966 to December 2003 identified all randomized control trials that evaluated NAC in those patients at risk of acute renal failure (ARF) following either angiographic or CT scan contrast exposure. All studies included in the review employed the use of either low-osmolar (n = 9 trials) or iso-osmolar (n = 2 trials) contrast agents. The outcome of interest was ARF as defined by a rise in serum creatinine (Cr > or = 0.5 mg/dl rise or > 25% increase from baseline) after exposure to contrast. The data were aggregated by the methods of Mantel and Haenszel. RESULTS: The overall summary odds ratio estimate of 0.46 (95% confidence interval 0.32 - 0.66) suggests a strong protective effect of NAC in preventing radiographic-induced nephropathy. CONCLUSION: In summary, there is good aggregate trial evidence to suggest that patients who have an elevated serum creatinine level at baseline benefit from receiving periprocedure NAC in the prevention of contrast-induced ARF.