The use of allopurinol in prophylaxis against contrast-induced nephropathy in patients undergoing percutaneous coronary intervention

Abstract Background Contrast-induced nephropathy (CIN) is a serious complication after percutaneous coronary intervention (PCI). Inflammation and development of reactive oxygen species are among the postulated mechanisms of CIN. Allopurinol with anti-inflammatory action could be a preventive method of CI-AKI. Aim of the work To determine the effect of adding allopurinol to hydration in the prevention of CIN in patients undergoing PCI, with or without hyperuricemia. Methods One hundred and seven patients with moderate to high Mehran score undergoing elective PCI were randomly allocated to the allopurinol (n=52) or the control group (n=55). Those in the allopurinol group (hyperuricemic n=25, and normouricemic n= 27) received allopurinol 300 mg one day and one hour before PCI beside intravenous hydration (1 ml/kg/hour) normal saline, a maximum of 100 ml/hour for 12 hours pre and post coronary angiography. Patients in the control group (hyperuricemic n=26 and normouricemic n=29), received the same intravenous hydration only. Serum creatinine and urea were measured before and 48 hours after the procedure while the uric acid level was measured before the procedure only. CIN was defined by a percentage increase in serum creatinine of ≥25% or absolute serum creatinine ≥0.5 mg/dl, 48 hours after PCI. Results The mean age of the studied patients was 59.6 ± 9.1 years old, 59% were male. No difference between both groups regarding baseline characteristics or medications. Average Mehran score was 9.0 ± 1.2. CIN was observed in 5 patients in the allopurinol group (9.6%) and 15 patients in the control group (27.3%) (P = 0.017). There was no significant difference between both groups regarding the contrast volume (179.8 ± 68.1 vs. 153.8 ± 57.9 ml, p: 0.052). Hyperuricemia had no significant effect on increasing the incidence of CI-AKI either in patients with or without CKD (p=0.964). Conclusion Allopurinol on the top of hydration was found to decrease the incidence of CIN following PCI in patients with moderate to high Mehran score for CIN. The anti-inflammatory action of allopurinol could be the mechanism of this favorable effect, as baseline uric acid didn't affect the results. Further multi-center study with a larger sample size is needed to offer more definite results.