Antibiotic Administration within Two Days after Successful Endoscopic Retrograde Cholangiopancreatography Is Sufficient for Mild and Moderate Acute Cholangitis.

To prevent the increase of resistant bacteria, it is important to minimize the use of antimicrobial agents. Studies have found that administration for ≤3 days after successful endoscopic retrograde cholangiopancreatography (ERCP) is appropriate. Therefore, the present study aimed to verify if administration of antimicrobial agents can be further shortened to ≤2 days after ERCP. We divided 390 patients with mild and moderate cholangitis who underwent technically successful ERCP from January 2018 to June 2020 and had positive blood or bile cultures into two groups: antibiotic therapy within two days of ERCP (short-course therapy, SCT; n = 59, 15.1%), and for >3 days (long-course therapy, LCT; n = 331, 84.9%). The increased severity after admission and other outcomes were compared between the two groups, and the risk factors for increased severity were verified. There were no between-group differences in patient characteristics. Total length of hospital stay was shorter in SCT than in LCT, and other outcomes in SCT were not significantly different from those in LCT. Being 80 or older was a risk factor for increased severity; however, SCT was not associated with increased severity. Antimicrobial therapy for ≤2 days after successful ERCP is adequate in patients with mild and moderate acute cholangitis.