Catatonia Due to Tacrolimus Toxicity 16 Years After Renal Transplantation: Case Report and Literature Review.

Tacrolimus, a potent posttransplant immunosuppressant, has been associated with major neuropsychiatric complications, including catatonia and psychosis. We report a novel case of tacrolimus-induced encephalopathy that developed 16 years after renal transplantation while the drug was at a therapeutic level. Discontinuation of tacrolimus and switching to an alternative immunosuppressant resulted in significant clinical improvement over 1 week. Our experience illustrates the possibility of acute neurotoxicity from tacrolimus even when the patient has tolerated the drug for 16 years and drug levels are within the therapeutic range. This case also highlights the importance of collaboration between psychiatry and transplant clinicians.