Low-dose rectal diclofenac for prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis: a randomized controlled trial

Acute pancreatitis is a common complication of endoscopic retrograde cholangiopancreatography (ERCP). Rectal nonsteroidal anti-inflammatory drugs (specifically, 100 mg of diclofenac or indomethacin) have shown promising prophylactic activity in post-ERCP pancreatitis (PEP). However, the 100-mg dose is higher than that ordinarily used in Japan. We performed a prospective randomized controlled study to evaluate the efficacy of low-dose rectal diclofenac for the prevention of PEP. Patients who were scheduled to undergo ERCP were randomized to receive a saline infusion either with 50 mg of rectal diclofenac (diclofenac group) or without (control group) 30 min before ERCP. The dose of diclofenac was reduced to 25 mg in patients weighing < 50 kg. The primary outcome measure was the occurrence of PEP. Enrollment was terminated early because the planned interim analysis found a statistically significant intergroup difference in the occurrence of PEP. A total of 104 patients were eligible for this study; 51 patients received rectal diclofenac. Twelve patients (11.5%) developed PEP: 3.9% (2/51) in the diclofenac group and 18.9% (10/53) in the control group (p = 0.017). After ERCP, the incidence of hyperamylasemia was not significantly different between the two groups. Post-ERCP pain was significantly more frequent in the control group than in the diclofenac group (37.7 vs. 7.8%, respectively; p < 0.001). There were no adverse events related to diclofenac. Low-dose rectal diclofenac can prevent PEP.