Coadministration of Erythromycin to Increase Tacrolimus Concentrations in Liver Transplant Recipients

We evaluated the effects of using erythromycin (ERY) in liver transplant recipients to improve the early postoperative control of tacrolimus (TAC) concentration.

This study adopts a retrospective medical record analysis method from January 2015 to December 2017. Assessment items include TAC daily dose (D), TAC whole blood trough level (Co), rejection episodes, and adverse effects. The magnitude of ERY inhibition on TAC metabolism was decided by analyzing dose-corrected trough concentration (Co/D). Oral 250 mg ERY every day to every other day was prescribed when patients needed to swallow more than 10 capsules of TAC per day, TAC trough levels rose too slowly, and/or acute rejection occurred. TAC trough levels were obtained daily. ERY was stopped when the TAC trough level was above 10 ng/mL or rejection episode relieved.

A total of 8 liver transplant recipients was collected. Oral ERY was administered at 6 to 13 days after transplantation. The duration of ERY regimen was 2 to 7 days. The average initial and maximum Co/D was 0.6 ± 0.0 and 1.8 ± 1.0. After ERY was deleted, Co/D was back to the value without ERY at about 2 to 20 days. The magnitude of interaction between tacrolimus and erythromycin is 1.4- to 4.6-fold. The highest dose of TAC was 10 to 12 mg/d. There were no drug-related complications during this period. Acute rejection relapsed in 1 patient after we stopped ERY.

Coadministration of ERY and TAC is a strategic choice for liver transplant recipients whose TAC blood concentration was difficult in approaching therapeutic levels.