What is a contraindication for administering Clozapine?

Clozapine is an atypical antipsychotic that is primarily used to treat treatment-resistant schizophrenia. A crucial aspect of its use is monitoring the patient’s white blood cell (WBC) count, particularly the absolute neutrophil count (ANC). The potential for serious side effects, particularly agranulocytosis, which is a dangerously low level of neutrophils, is a significant risk associated with Clozapine. Administering Clozapine to a patient who already has a low WBC count poses a substantial risk of further lowering the WBC count, leading to severe complications. Therefore, a low WBC count serves as a absolute contraindication for the use of Clozapine, necessitating the need for regular blood monitoring during treatment.

The other options may present considerations for clinical management, but they do not have the same level of critical contraindication associated with the use of Clozapine. High blood pressure, recent surgery, and diabetes may require careful management or monitoring, but they do not inherently prevent the administration of this medication.