Two cases of acute kidney injury secondary to the combined use of clozapine and lithium carbonate

Abstract

Clozapine is commonly accepted as an effective therapeutic agent for treatment-resistant schizophrenia. However, widespread clozapine use in recent years has led to an increase in the number of patients who experience various adverse effects associated with its administration. We describe two patients who were transferred to our hospital with acute kidney injury secondary to the combined use of clozapine and lithium carbonate. Case 1: The patient developed renal dysfunction caused by lithium carbonate-induced diabetes insipidus approximately 5 weeks after clozapine initiation. This patient received modified electroconvulsive therapy for the management of psychotic symptoms after discontinuation of clozapine. Case 2: The patient developed renal dysfunction caused by acute interstitial nephritis secondary to clozapine use, approximately 2 weeks after clozapine initiation. This patient also developed lithium poisoning. We discontinued the administration of clozapine and lithium carbonate in both patients, and infusion management alone improved the patients’ renal function. Patients with treatment-resistant schizophrenia often have mood swings. Therefore, as the use of clozapine becomes more widespread in Japan, the number of patients receiving combination therapy with clozapine and lithium carbonate is expected to increase in the future. Psychiatrists should be aware of the risk of renal dysfunction associated with this therapy, and careful renal function monitoring is warranted in such cases. The efficacy and safety of clozapine and lithium carbonate combination therapy should be carefully evaluated in patients who receive this treatment.