AUTHOR=Wang Rongrong , Wang Weili , Ma Kuifen , Duan Xin , Wang Fangfang , Huang Mingzhu , Zhang Wei , Liang Tingbo 

TITLE=Variation in Tacrolimus Trough Concentrations in Liver Transplant Patients Undergoing Endoscopic Retrograde Cholangiopancreatography: A Retrospective, Observational Study

JOURNAL=Frontiers in Pharmacology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2020.01252

DOI=10.3389/fphar.2020.01252

ISSN=1663-9812

ABSTRACT=<sec><title>Objective</title><p>High variabilities in tacrolimus (TAC) exposure are still problems that confuse physicians. TAC trough levels (TAC C<sub>min</sub>) fluctuated considerably after endoscopic retrograde cholangiopancreatography (ERCP) treatment in several liver transplant (LT) patients. We aimed to investigate the variation regularity of TAC C<sub>min</sub> post-ERCP and related factors.</p></sec><sec><title>Methods</title><p>This study was a retrospective, observational study conducted at the First Affiliated Hospital of Zhejiang University in China. From October 2017 to January 2019, 26 LT patients that received ERCP were included (73 TAC C<sub>min</sub> measures). The absolute difference and the variation extent in TAC C<sub>min</sub> pre- and post-ERCP were analyzed. Patients were divided into mild and obvious variation groups, and the differences were compared.</p></sec><sec><title>Results</title><p>The TAC C<sub>min</sub> in LT patients significantly increased in the first three days post-ERCP (<italic>p</italic>&lt;0.05) and increased by more than 20% in 18 out of 26 (69.2%) patients. The mean extent of variation in TAC C<sub>min</sub> was 45.1% (95% confidence interval [CI]: 28.3–81.3%) and 31.4% (95% CI: 9.7–53.1%) on days 1 and 3 post-ERCP, respectively. The increasing TAC C<sub>min</sub> gradually returned to baseline within a week (<italic>p</italic>&gt;0.05). The daily TAC dose and total bile acid (TBA) level were significantly higher (<italic>p</italic>&lt;0.05) in patients with obvious variation in TAC C<sub>min</sub>. The differences in other demographics, clinical characteristics, variation in laboratory data, and serum amylase levels between the two groups were not significant.</p></sec><sec><title>Conclusion</title><p>The TAC C<sub>min</sub> significantly increased in LT patients during the first three days after ERCP, and the level returned to baseline within a week. The daily TAC dose and TBA levels may be related to this increase. Frequent drug concentration monitoring should be executed in the early phase post-ERCP, especially in patients with related factors.</p></sec>