Second-generation (atypical) antipsychotic
Antagonist at dopamine D2 receptors with rapid dissociation; high affinity antagonist activity at dopamine D4 and D3 receptors; also blocks serotonin 5-HT2A/2C, histamine H1, muscarinic, and adrenergic receptors, contributing to its unique efficacy and side effect profile
Treatment-resistant schizophrenia, reduction of suicidal behavior in schizophrenia or schizoaffective disorder
Psychosis in Parkinson’s disease (PD), Lewy body dementia (LBD), severe agitation in neurodevelopmental disorders and neurodegenerative conditions
Oral tablets
12.5–25 mg p.o. daily initially, titrated slowly to reduce risk of hypotension and sedation
150–600 mg/day
Half-life ~12 hours; metabolized primarily via CYP1A2 and CYP3A4; steady state in approximately 1 week
Sedation, sialorrhea (excessive salivation), constipation, orthostatic hypotension, tachycardia, weight gain
Agranulocytosis, seizures, myocarditis, cardiomyopathy, bowel obstruction, neuroleptic malignant syndrome (NMS)
Mandatory absolute neutrophil count (ANC) monitoring weekly for 6 months, then every 2 weeks for 6 months, then monthly if stable; also monitor weight, fasting glucose, lipids, blood pressure, and seizure risk
Severe neutropenia/agranulocytosis, myocarditis, seizures, orthostatic hypotension, increased mortality in elderly patients with dementia-related psychosis
Clozapine is preferred for managing psychosis in Parkinson’s disease and Lewy body dementia due to minimal extrapyramidal symptoms (EPS). It may reduce aggression and self-injurious behavior in individuals with intellectual disability or traumatic brain injury (TBI). Close monitoring of hematologic parameters, seizure risk, and cardiac function is critical, especially in older adults or medically complex patients.