Background: While recipient cytochrome P450 (CYP) genetic polymorphisms are established modulators of tacrolimus (TAC) pharmacokinetics, the combined effects of donor-derived hepatic and recipient intestinal CYP3A4/5 and CYP2C19 genotypes during voriconazole (VRC)-mediated CYP3A inhibition remain inadequately elucidated in liver transplantation. Objectives: This study evaluated the impact of donor and recipient CYP3A4/5 and CYP2C19 polymorphisms on TAC pharmacokinetics during VRC co-therapy in liver transplant recipients. Design: A retrospective study was conducted on 139 liver transplant patients receiving TAC-based immunosuppressive therapy at the First Affiliated Hospital of Sun Yat-sen University from December 2016 to June 2025. Methods: The liver transplant recipients were stratified into a VRC co-therapy group ( n = 33) and a non-VRC control group ( n = 106). TAC dose-corrected trough concentrations (C 0 /D) were analyzed in relation to donor and recipient genotypes of CYP3A4*1G (rs2242480), CYP3A5*3 (rs776746), CYP2C19*2 (rs4244285), and CYP2C19*3 (rs4986893). Results: During VRC co-therapy, dual donor-recipient CYP3A4*1G CC carriers exhibited a 73% increase in TAC C 0 /D compared with TT/TC genotypes (6.83 vs 3.95, p = 0.0031). Recipients grafted from CYP3A5 non-expresser donors exhibited 34% higher TAC C 0 /D than those from CYP3A5 expressers (6.35 vs 4.75, p = 0.0196). Recipient CYP2C19 poor metabolizers demonstrated 36% elevated TAC C 0 /D compared to extensive or intermediate metabolizers (6.47 vs 4.76, p = 0.0401). The magnitude of TAC-VRC interaction was modulated by both donor and recipient genotypes. Comparing with the control group, VRC co-therapy increased TAC C 0 /D by 3.80- and 2.75-fold increases in CYP3A5 expresser and non-expresser recipients, respectively, and by 3.44- and 3.53-fold in recipients grafted from CYP3A5 expresser and non-expresser donors, respectively. Post-VRC discontinuation, TAC C 0 /D remained significantly elevated for 5 days before returning to baseline level by day 6 ( p < 0.0001). Conclusion: In summary, Donor and recipient CYP3A4/5 and CYP2C19 genotypes jointly influence TAC pharmacokinetics during VRC co-therapy. Genotype-guided dosing strategies integrating both donor and recipient genotypes may improve TAC dosing precision. TAC dose reinstatement may be deferred until day six following VRC discontinuation to avoid overexposure.
Li et al. (Sun,) studied this question.