Clozapine re-challenge under the cover of Filgrastim

Rechallenge with clozapine, despite a history of clozapine-induced neutropenia is considered in patients with a good response to the drug in the past, for whom no other treatments are effective, and in cases where the risks of withholding treatment are greater than the risks of rechallenge. Dyscrasias that occur during rechallenge are reportedly earlier in onset and longer lasting. Strategies advocated during rechallenge include frequent monitoring of white blood counts, the use of lithium or Granulocyte-Colony Stimulating Factors. We report a case of a patient with treatment-resistant schizophrenia who developed neutropenia with clozapine as a result of which the drug was discontinued. However poor response to other first and second-generation antipsychotic medication and the persisting risk of harm to himself and others necessitated the reconsideration of clozapine. The patient was re-challenged with clozapine under the cover of Filgrastim, a Granulocyte-Colony Stimulating Factor.