Clozapine is an atypical antipsychotic that is used to treat treatment-resistant schizophrenia, treatment-resistant bipolar disorder and used for reduction of recurrent suicidal behavior. According to Stahl (2021), “Clozapine is widely recognized as being particularly effective when other drugs for psychosis fail and is thus the “gold standard” for efficacy in schizophrenia. Clozapine is also the only antipsychotic that has been documented to reduce the risk of suicide in schizophrenia and may have a particular niche in treating aggression and violence in psychotic patients” (p. 222).
Clozapine works by blocking dopamine 2 receptors. This leads to the reduction of positive symptoms of psychosis and the stabilization of disturbing symptoms. It also blocks serotonin 2A receptors. This causes increased release of dopamine in the brain which decreases motor side effects and improving cognitive symptoms (Stahl, 2017).
One possible side effect of Clozapine is neutropenia. Neutropenia is a very low count of the white blood cell neutrophils. White blood cells help your body fight of infections. Having a very low WBC count can put the body at an increased risk for infection. It is important for the patient to have serial WBC checks while on Clozapine. Other side effects may include sedation, weight gain, orthostasis, tachycardia and tardive dyskinesia. Tardive dyskinesia (TD) symptoms include abnormal and involuntary movements of the face (specifically the tongue, jaw and lips). TD may sometimes become permanent. It is extremely important to recognize the symptoms of TD early so that an intervention can occur. An intervention may include lowering the dose of Clozapine or changing to a different drug entirely.
The time it takes for Clozapine to work is around 3 weeks. Dosing of Clozapine starts out with 25 mg at night. Then increase by 25-50 mg/day every 48-72 hours. The threshold for response is a plasma level of 350 ng/ml (Stahl, 2017).