Efficacy of N-acetylcysteine and aminophylline in preventing contrast-induced nephropathy

Background: Contrast-induced nephropathy (CIN) is one of the important complications of coronary angiography (CAG) and percutaneous coronary intervention (PCI), especially in patients with chronic kidney disease (CKD). Prophylactic administration of N-acetylcysteine (NAC) and aminophylline has been reported to be effective in some trials, but the results still remain controversial. We investigated the efficacy of NAC or aminophylline in preventing CIN.

Methods and results: Forty-five consecutive patients undergoing CAG and/or PCI were randomly assigned to receive hydration and NAC (704 mg orally twice daily; NAC group, n=15), hydration and aminophylline (250 mg intraveneously 30 min before CAG and/or PCI; aminophylline group, n=15), or hydration alone (control group, n=15). We compared serum creatinine (SCr), creatinine clearance (Ccr), blood beta-2 microglobulin, and urinary beta-2 microglobulin levels at baseline and 48h after CAG and/or PCI. In the NAC group, SCr decreased from 1.00 + or - 0.36 to 0.67 + or - 0.16 mg/dl (p<0.01), and Ccr significantly increased from 62.4 + or - 15.6 to 80.4 + or - 8.39 ml/min (p<0.01). In the aminophylline group, SCr and Ccr were unchanged. In the control group, SCr significantly increased from 0.94 + or - 0.21 to 1.28 + or - 0.21 mg/dl (p<0.01), and Ccr significantly decreased from 63.7 + or - 16.1 to 46.1 + or - 10.6 ml/min (p<0.01) after CAG and/or PCI. In the NAC group, mean blood beta-2 microglobulin significantly decreased from 2.38 + or - 0.58 to 1.71 + or - 0.38 mg/dl (p<0.01), and in the aminophylline group, mean urinary beta-2 microglobulin concentration significantly decreased from 337 + or - 31.0 to 239 + or - 34 microg/ml (p<0.01).

Conclusions: These results suggest that both prophylactic NAC and aminophylline administration are effective in preventing CIN, but not with hydration alone. It appears that the two compounds work in different ways against CIN.