Treatment of severe clozapine-induced neutropenia with granulocyte colony-stimulating factor (G-CSF)

BACKGROUND: A 17-year-old boy suffering from a severe schizophrenic disorder of the paranoid type and mental retardation did not respond to treatment with typical antipsychotics, whereas under clozapine treatment he showed a favourable response. Discontinuation of clozapine led to an acute psychotic relapse. During clozapine treatment the patient developed severe neutropenia. METHOD AND RESULTS: Due to the history of unsatisfactory response to traditional antipsychotics, clozapine treatment was continued despite white blood cell (WBC) decline. Concomitant treatment with G-CSF was followed by a rapid normalisation of WBC. CONCLUSIONS: This case report is not intended to challenge the clinical practice of discontinuing clozapine upon the development of neutropenia/agranulocytosis, but rather to stimulate further research in the pathophysiology and clinical consequences of a clozapine rechallenge after a WBC decline, especially in patients with a rather complex symptomatology where no sufficient therapeutic results can be achieved with any other pharmacological intervention than clozapine.