Meta-analysis: allopurinol in the prevention of postendoscopic retrograde cholangiopancreatography pancreatitis

Background Several clinical trials evaluating the prophylactic effect of allopurinol on postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis have been published; however, there is no consensus on whether prophylactic allopurinol can reduce the incidence of post-ERCP pancreatitis. Aim To compare prophylactic allopurinol with placebo on post-ERCP pancreatitis reduction by performing a meta-analysis in randomized controlled trials. Methods Databases including MEDLINE, EMBASE and the Cochrane Library, Science Citation Index were searched to find relevant trials. Two reviewers independently identified relevant randomized controlled trials assessing the effect of prophylactic allopurinol on the incidence of post-ERCP pancreatitis. Outcome measures were the incidence of post-ERCP pancreatitis. Results Four trials involving 1730 patients were included. Analysis suggested that post-ERCP pancreatitis rates were not significantly different (allopurinol 8.9%, placebo 9.7%, P = 0.68), RR 0.86 (95% CI: 0.42, 1.77). Subsequent subgroup analysis confirmed that allopurinol was not statistically superior to placebo in reducing post-ERCP pancreatitis. Conclusions Based on current best evidence, prophylactic allopurinol may not be useful for post-ERCP pancreatitis reduction.