Clozapine in Solid Organ Transplant: A Literature Review and Case Series

Current experience with the management of clozapine in patients needing solid organ transplant (SOT) is sparse. Clozapine is an essential antipsychotic for many patients with treatment-resistant schizophrenia that cannot be replaced by other antipsychotics without the risk of psychotic relapse. However, clozapine is associated with many side effects, including neutropenia, that may interact with immunosuppressive therapies during organ transplantation. We conducted a literature review of clozapine use during SOT and a retrospective case review using natural language processing of the Partners Research Patient Data Registry to identify individuals over the age of 18 years who had taken clozapine at any time and been evaluated for or undergone SOT-we identified 15 patients who met this criterion. Three patients underwent renal transplantation while remaining on clozapine, and 1 patient started clozapine after renal transplant, all without complication. We have additionally included an illustrative case report to summarize our direct experience of continuing clozapine through lung transplant, highlighting the first known case in this population. Finally, we provide clinical guidance for the management of clozapine and associated side effects during SOT. Proactive consultation with psychiatry may avoid abrupt cessation of clozapine, which can result in severe clozapine withdrawal, and increase the number of patients on clozapine considered for SOT.