Bradycardia associated with intravenous administration of tacrolimus in a liver transplant recipient.

Cardiotoxicity due to tacrolimus is documented infrequently in the medical literature. Sinus bradycardia associated with intravenous tacrolimus occurred in a 15-year-old orthotopic liver transplant recipient. The mechanism of this adverse effect is unknown; however, it does not appear to be concentration dependent, and in this patient it resolved on changing to oral therapy. Practitioners should be aware that intravenous administration of tacrolimus may be associated with adverse cardiac events including sinus bradycardia.