ABSTRACT
BACKGROUND: An extended-release formulation of tacrolimus designed for once-daily administration (LCP-TAC) is a new prolonged-release tacrolimus (TAC-PR) formulation using a drug delivery technology designed to enhance the bioavailability of drugs compared with TAC-PR. The aim of this study was to retrospectively compare de novo administration of LCP-TAC and TAC-PR for therapeutic trough levels and daily dosage during the first 30 days after first liver transplant (LT). METHODS: A total of 35 patients submitted to first LT between 2016 and 2018 were retrospectively enrolled: 16 received LCP-TAC, while 19 received TAC-PR as de novo immunosuppression. Patients were analyzed for daily dosage and trough levels at postoperative days (PODs) 3, 7, 15, and 30. RESULTS: The initial dose of tacrolimus did not differ between LCP-TAC and TAC-PR (mean, 5.19 [SD, 1.72] mg/d vs mean, 5.26 [SD, 1.91] mg/d, P = .90). On PODs 7, 15, and 30 the daily dosage was statistically lower for LCP-TAC compared with TAC-PR (mean, 5.44 [SD, 2.06] mg/d vs mean, 7.68 [SD, 2.91] mg/d, P = .01; mean, 5.33 [SD, 2.23] mg/d vs mean, 8.82 [SD, 2.35] mg/d, P < .001; and mean, 5.38 [SD, 2.50] mg/d vs mean, 9.81 [SD, 3.78] mg/d, P < .001, respectively). The therapeutic trough levels were significantly higher for LCP-TAC on POD 3 (mean, 5.05 [SD, 3.58] ng/mL vs mean, 2.42 [SD, 2.75] ng/mL, P = .03) and POD 5 (mean, 7.35 [SD, 5.12] ng/mL vs mean, 4.17 [SD, 2.05] ng/mL, P = .04), while no differences were found on PODs 7, 15, and 30.The percentage of patients on POD 3 achieving a trough level higher than 6 ng/mL was higher for LCP-TAC than TAC-PR (40% vs 13%, P = .05). CONCLUSIONS: LCP-TAC after LT is safe and might enhance bioavailability, reducing the amount of drug necessary to achieve therapeutic trough levels compared with TAC-PR.