Lithium and clozapine.(Drug-Drug Interactions)(Case study)

Although clozapine (Clozaril) is very effective in managing treatmentresistant schizophrenia, the occurrence of neutropenia and agranulocytosis in 1-2% of treated patients limits its broader usefulness. (1) In addition, benign ethnic neutropenia, characterized by low white blood cell (WBC) count and absolute neutrophil count (ANC) without increased susceptibility to infection, has been observed in 25-50% of minority populations, including African Americans. (2)

Typically, clozapine will be discontinued when the patient's WBC count is less than 3,000 cells/^l or ANC is less than 1,500 cells/|Ji. Unfortunately, discontinuation of clozapine usually leads to significant recurrence in psychotic symptoms and a higher dose if therapy re-initiation is necessary. Re-initiating clozapine in …