Horizons in TransplantationLiver transplantationSublingual Tacrolimus in Liver Transplantation: A Valid Option?

•Oral tacrolimus is currently the pillar of maintenance immunosuppression after solid organ transplantation. In select transplant recipients, sublingual administration has emerged as an alternate route of drug delivery; however, data regarding its use in adult liver transplant recipients are limited.•Transition to sublingual was performed during the patient's hospital stay and was based on an approximated equivalence of 2 mg oral tacrolimus = 1 mg sublingual tacrolimus (1:2 dose-conversion rate). Teaching and education was given in every case by designated transplant pharmacists and nurses.•All patients tolerated the sublingual administration of tacrolimus very well without any side effects or complications requiring dose reduction or discontinuation. Specifically, there were no episodes of nephrotoxicity, hepatotoxicity, or anaphylaxis.•Based on our experience, sublingual administration of tacrolimus in adult liver transplant recipients is safe (ie, no side effects seen) and effective.

BackgroundOral tacrolimus (Tac) is currently the pillar of maintenance immunosuppression after solid organ transplantation. Recent studies proposed sublingual (SL) administration as an alternative; however, data regarding its use in adult liver transplant (LT) recipients are limited.MethodsThree LT recipients were included. Two (patients 1 and 2) were transitioned from oral to SL Tac owing to persistently erratic serum concentrations and 1 (patient 3) because of severe oral intolerance. SL Tac was started in a 1:2 dose-conversion rate.ResultsAll patients tolerated the SL Tac well without any side effects requiring dose reduction or discontinuation. In patients 1 and 2, the therapeutic trough concentrations improved significantly after switching to SL Tac: 20% (10/50) on oral Tac to 50% (7/14) on SL Tac in patient 1 (P = .04), and from 0% (0/15) oral Tac vs 40% (4/10) on SL Tac in patient 2 (P = .02). Patient 2, who had consistently subtherapeutic trough levels on oral Tac (mean trough of 2.6 ± 0.7 ng/mL), achieved a stable therapeutic level on SL Tac (mean trough 8.1 ± 2.7 ng/mL; P < .001). In patients 1 and 3, the mean trough levels remained unchanged: 5.1 ± 1.9 ng/mL on oral Tac versus 5.3 ± 1.6 ng/mL on SL Tac (P = .76), and 4.3 ± 1.3 ng/mL on oral Tac versus 4.2 ± 1.9 ng/mL on SL Tac (P = .76), respectively.ConclusionsOral administration of Tac is the criterion standard route for drug delivery; however SL administration should be considered as a safe alternative when the oral method is not an option.