Long-term combination treatment with clozapine and filgrastim in patients with clozapine-induced agranulocytosis.

Short-term treatment with granulocyte colony-stimulating factor has been successful in reducing the duration of clozapine-induced agranulocytosis. Long-term combination treatment with filgrastim and clozapine in patients with clozapine-induced agranulocytosis has only been described in two previous cases. We describe three patients with schizophrenia who developed granulocytopenia or agranulocytosis during treatment with clozapine and who did not respond to other antipsychotics. The patients received long-term combination treatment with clozapine and filgrastim. Using a combination treatment with filgrastim and clozapine, the psychotic symptoms were successfully controlled and no haematological complications were observed during the follow-up periods of 11, 30 and 48 months, respectively. Our cases suggest that long-term treatment with filgrastim might be a useful, but exceptional, treatment approach in patients who have developed clozapine-induced granulocytopenia or agranulocytosis.