Intravenous N-acetylcysteine does not prevent post-ERCP pancreatitis

Acute pancreatitis remains the most common complication of ERCP. Prophylactic administration of N-acetylcysteine (NAC) probably decreases the incidence and the severity of experimental pancreatitis. The aim of the present study was to assess the efficacy of intravenous NAC for prevention of post-ERCP pancreatitis in humans, who represent an appropriate model to study the potential role of NAC in this setting.

A prospective, double-blind, placebo-controlled trial was conducted in 256 patients who underwent ERCP. Patients were randomized to receive intravenous NAC at a loading dose of 70 mg/kg 2 hours before and 35 mg/kg at 4-hour intervals for a total of 24 hours after the procedure, or to receive normal saline solution as placebo. Patients were clinically evaluated, and serum amylase levels were measured before and 6 hours and 24 hours after the procedure. Standardized criteria were used to diagnose and to grade the severity of post-ERCP pancreatitis.

A total of 249 patients were included in the analysis. The two groups were matched for age, gender, underlying disease and indication for treatment, ERCP findings, and type of treatment. The overall incidence of post-ERCP acute pancreatitis was 10.8%, with 12.1% in the NAC group and 9.6% in the placebo group. There were no statistical differences in the incidence or severity grades between the groups. The mean duration of hospitalization for pancreatitis also was similar in the NAC group and the placebo group (3.6 +/- 0.9 and 3 +/- 1.5 days, respectively).

The results of this trial show the absence of any beneficial effect of NAC on the incidence and the severity of ERCP-induced pancreatitis.