What serious adverse effect is associated with Clozapine (Clozaril)?

Clozapine, an atypical antipsychotic, is uniquely associated with agranulocytosis, a potentially severe and life-threatening decrease in the number of white blood cells (specifically neutrophils). This condition can significantly increase the risk of infections due to the body's compromised immune response. The occurrence of agranulocytosis necessitates regular monitoring of the white blood cell count in patients taking clozapine. The risk of agranulocytosis is a critical consideration in treatment decisions and highlights the importance of this medication, as it can be effective for treatment-resistant schizophrenia but comes with this serious adverse effect. In contrast, while sedation, weight gain, and dry mouth are known side effects of clozapine, they do not carry the same level of severity or risk as agranulocytosis, making it the most notable and serious adverse effect linked to this medication.