Abstract
Background/Aims: Tacrolimus (Tac) is an immunosuppressant that is widely used to prevent allograft rejection in patients after liver transplantation. Recently, a Chinese herbal medicine known as Wuzhi Capsule (WZC) was shown to increase Tac blood concentrations by inhibiting the activity of CYP3A5 in animal studies in rats. To date, it remains unexplored whether WZC can be used to reduce the dose requirement for Tac in liver transplant patients with different donor-recipient CYP3A5 genotypes. Materials and Methods: A total of 185 liver transplant patients were enrolled and were divided into four groups according to the combinations of donor-recipient CYP3A5 phenotypes. WZC was given to patients who had C0/D of Tac ≤ 1 ng/ml per mg and required a dose of Tac ≥ 4 mg. Results: The R+/D+ group had the lowest C0, C0/D, and C0/D/W among the four groups. Furthermore, a larger proportion of patients in the CYP3A5 expression groups required Tac dose adjustment to achieve a therapeutic effect and were given Tac with WZC. Notably, the use of WZC significantly increased the blood concentrations of Tac in the CYP3A5 expression groups. Conclusion: WZC significantly increased the C0, C0/D, and C0/D/W in the CYP3A5 expression groups.