Conversion ratio of tacrolimus switching from intravenous infusion to oral administration after lung transplantation.

Background: To investigate the conversion ratio of tacrolimus switching from intravenous infusion to oral administration in patients after lung transplantation. Methods: We retrospectively recruited patients received lung transplantation in the First Affiliated Hospital of Guangzhou Medical Hospital from January 2015 to June 2019. The blood concentration of tacrolimus administrated through intravenous infusion and oral administration were collected. The blood concentration, concentration/dose ratio (C/D), and (C/Dpo)/(C/Div) ratio were analyzed to explore the conversion ratio of tacrolimus switching from intravenous infusion to oral administration, as combined medication of tacrolimus and caspofungin were used. Results: The concentration of intravenously administered tacrolimus was significantly higher than that of oral administration; the C/D ratio of intravenously administrated tacrolimus (C/Div) was significantly higher than that of the oral administration (C/Dpo). There was a significant correlation between C/Dpo and C/Div (R-2 =0.774, P<0.001). The conversion ratio of tacrolimus from intravenous administration to oral administration was 1:7.4, as combined medication of tacrolimus and caspofungin were used. Conclusions: The conversion ratio of tacrolimus switching from intravenous to oral administration is 1:7.4 in the combination treatment of tacrolimus and caspofungin after lung transplantation.