Prospective randomized double-blind placebo-controlled trial of glyceryl trinitrate in endoscopic retrograde cholangiopancreatography-induced pancreatitis

Background: One possible aetiology of pancreatitis following endoscopic retrograde cholangiopancreatography (ERCP) is cannulation-induced spasm of the sphincter of Oddi and consequent pancreatic duct obstruction. Sublingual glyceryl trinitrate (GTN) has been shown to produce periampullary sphincter relaxation. The aim of this study was to determine whether prophylactic long-acting GTN could reduce the incidence of ERCP-induced pancreatitis. Methods: In a randomized double-blind study, prophylactic treatment with GTN (2 mg given sublingually 5 min before endoscopy) was compared with placebo in 186 patients who presented for elective ERCP. The primary endpoint was the occurrence of pancreatitis within 24 h, defined as a serum amylase concentration greater than 1000 units/ml in association with a visual analogue pain score of more than 5. Results: The incidence of pancreatitis was lower in the GTN group compared with placebo (seven of 90 versus 17 of 96; P < 0.05). Mean serum amylase values were similar in the two groups. The protective effect of GTN appears to be highest in the diagnostic ERCP group (one of 54 versus ten of 66; P = 0.012) and in the group in which cholangiography alone was performed (one of 54 versus eight of 57; P = 0.032). Conclusion: Prophylactic treatment with GTN reduces the incidence of pancreatitis following ERCP but does not seem to reduce the extent of hyperamylasaemia or the severity of pancreatitis.