Effect of Jejunal Administration on Tacrolimus Trough Concentrations in a Pediatric Liver Transplant Recipient.

Maintenance immunosuppression regimens containing calcineurin inhibitors, specifically tacrolimus, are standard of care for rejection prevention in pediatric liver transplantation. Challenges with tacrolimus administration are common with pediatric patients, and guidance for non-oral, enteral administration of tacrolimus is limited. We report the case of an 11-year-old male orthotopic liver transplant recipient with a history of malnutrition requiring a jejunostomy tube (J-tube) for enteral nutrition and medication administration post-transplantation. Tacrolimus was initially given orally, and then transitioned to J-tube administration for 10 days. Tacrolimus trough concentrations declined significantly following conversion to J-tube administration and remained subtherapeutic despite a 3-fold dose increase. Once transitioned back to the oral route, trough concentrations became supratherapeutic requiring dose reductions until goal concentrations were achieved. This case demonstrates reduced bioavailability and need for increased dosing, when tacrolimus is administered through a J-tube.