Potential Role of Allopurinol in Preventing Contrast-Induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention: A Randomized Placebo-Controlled Trial.

Background: Contrast-induced nephropathy (CIN) is a major drawback in percutaneous coronary intervention (PCI). Significant uricosuria has been reported following contrast exposure. Allopurinol-a xanthine oxidase inhibitor-has been suggested to prevent the formation of oxygen-free radicals, which may contribute to CIN. The aim of the present study was to evaluate the possible efficacy of allopurinol in preventing CIN.

Methods: In this double-blind placebo-controlled trial, patients with an estimated glomerular filtration rate ≥60 mL/min who were admitted for elective PCI, were randomized to receive either allopurinol 600 mg or a placebo administered 24 h before the procedure, and again immediately before the procedure. Blood samples were drawn at 24 h before and 24 h after contrast exposure to measure serum creatinine (SCr), uric acid, and serum cystatin-c.

Results: The baseline characteristics were almost similar between the placebo and allopurinol groups. The overall change in SCr and the rate of CIN, which is defined as ≥25% increase in serum cystatin-c relative to baseline, failed to show a significant difference between the two groups. When adjusted on the baseline cystatin-c, SCr, sex, and positive family history, the difference in the overall increase in serum cystatin-c was statistically significantly lower in the allopurinol group.

Conclusions: Allopurinol administration in patients undergoing PCI failed to show efficacy in preventing CIN. Nevertheless, this effect should be further evaluated in the patient population with chronic kidney disease.