SUBJECTS AND METHODS: 48 patients with chronic renal insufficiency (mean [±SD] serum creatinine concentration, 2.06±0.56 mg/dL), who were undergoing coronary angiography with a nonionic, low-osmolar contrast agent, were prospectively studied. Patients were randomly assigned to receive either the antioxidant, NAC (600 mg orally twice daily), and 0.45% saline intravenously (n=25), before and after administration of contrast agents, or saline only (n=23). The renal function parameters were assessed 48 hour before and after radiocontrast media administration.

RESULTS: 14 of the 48 patients (29%) showed an increase in the 0.5 mg/dL serum creatinine concentration after 48 hours of contrast media administration: 4 of the 25 patients in the NAC group (16%) and 10 of the 23 in the control group (43%; p=0.036; relative risk, 0.37; 95% confidence interval, 1.04 to 7.79). In the NAC group, the mean serum creatinine concentration insignificantly increased (p=0.54), from 2.2±0.8 to 2.3±0.9 mg/dL, after 48 hours of contrast media administration; whereas, in the control group, the mean serum creatinine concentration significantly increased (p=0.011), from 1.9±0.4 to 2.2±0.8 mg/dL. The absolute change in serum creatinine concentration was significantly greater in the control than the NAC group (p=0.044).

CONCLUSION: Prophylactic oral administration of the antioxidant NAC, along with hydration, prevents the decrease in the renal function induced by a nonionic, low-osmolality contrast agent in patients with chronic renal insufficiency.