25 mg versus 50？mg dose of rectal diclofenac for prevention of post-ERCP pancreatitis in Japanese patients: a retrospective study

Objectives The aim of the present study was to assess the appropriate administration dose of non-steroidal anti-inflammation drugs to prevent pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). Importantly, the 100？mg dose of diclofenac recommended in Western countries has not been permitted in Japan. Design A retrospective study. Settings A single centre in Japan. Participants This study enrolled patients who underwent ERCP at the Department of Gastroenterology, Osaka Saiseikai Senri Hospital, from April 2011 through June 2013, and who received either a 25 or a 50？mg dose of rectal diclofenac after ERCP. Primary outcome measure The occurrence of post-ERCP pancreatitis (PEP). A multivariate regression model was used to assess the effect of the 50？mg dose (the 50？mg group) of rectal diclofenac and to compare it to the occurrence of PEP referring to the 25？mg group. Results A total of 155 eligible patients received either 25？mg (84 patients) or 50？mg (71 patients) doses of rectal diclofenac after ERCP to prevent PEP. The proportion of PEP was significantly lower in the 50？mg group than in the 25？mg group (15.5% (11/71) vs 33.3% (28/84), p=0.018). In a multivariate analysis, the occurrence of PEP was significantly lower in the 50？mg group than in the 25？mg group even after adjusting potential confounding factors (adjusted OR=0.27, 95% CI 0.11 to 0.70). Conclusions From this observation, the occurrence of PEP was significantly lower among ERCP patients with the 50？mg dose of rectal diclofenac than among those with the 25？mg dose