Clozapine-induced leukopenia successfully treated with lithium

A case of clozapine-induced leukopenia successfully treated with lithium is reported.

A 55-year-old man with paranoid schizophrenia who had been stable on clozapine for more than 10 years was admitted to an inpatient behavioral health unit with leukopenia associated with clozapine use. This patient's history was significant for four previous hospitalizations for psychiatric issues, none of which occurred while he was using clozapine. On admission, the patient's clozapine was discontinued and he was started on olanzapine. On hospital day 4, his white blood cell (WBC) count had risen to 3400/mm(3) and clozapine was resumed due to increasing auditory hallucinations and suicidal ideation. On hospital day 5, his WBC count decreased to 2900/mm(3) and clozapine was again stopped. The patient was given lithium carbonate 300 mg at bedtime, and olanzapine was discontinued. The next day, clozapine was restarted at 12.5 mg daily at bedtime. On hospital day 11, his WBC count had risen to 5400/mm(3). The patient was discharged on clozapine 25 mg at bedtime, with a WBC count of 3400/mm(3). The patient has not been rehospitalized and has not had significant changes in his WBC count or absolute neutrophil count (ANC) for more than 14 months.

A 55-year-old man with schizophrenia developed clozapine- induced leukopenia after more than 10 years of treatment. Lithium was used to stimulate leukocyte production, and clozapine was restarted successfully. The patient was maintained on clozapine and lithium without significant changes in his WBC count or ANC.