Clozapine
Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Clozapine is an atypical antipsychotic reserved for treatment-resistant schizophrenia and for reducing recurrent suicidal behavior in schizophrenia or schizoaffective disorder. It has unique efficacy but multiple boxed warnings, including severe neutropenia, orthostatic hypotension with bradycardia and syncope, seizures, myocarditis or cardiomyopathy, and increased mortality in elderly patients with dementia-related psychosis. ANC monitoring remains required by prescribing information even though FDA removed the Clozapine REMS program effective June 13, 2025.
Exploratory record, not a reviewed medical publication.
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This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Clozapine is an atypical antipsychotic reserved for treatment-resistant schizophrenia and for reducing recurrent suicidal behavior in schizophrenia or schizoaffective disorder. NutriStack rates the supporting evidence as strong. Common adult dosing is Start 12.5 mg once or twice daily and titrate slowly. Common target range is 300-450 mg/day in divided doses; maximum recommended dose is 900 mg/day., though a prescriber sets the actual dose. This profile indexes 3 sources.
The bottom line
Evidence rating strong. Most-documented uses: treatment-resistant schizophrenia after inadequate response to standard antipsychotics, reduction in recurrent suicidal behavior in schizophrenia or schizoaffective disorder, may reduce aggression or severe psychotic symptoms in selected refractory cases. 3 sources indexed (1988–2026), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Clozapine has complex receptor pharmacology, including dopamine D2/D4, serotonin 5-HT2A/2C, muscarinic, histamine H1, and alpha-adrenergic effects. Its antipsychotic efficacy in treatment resistance is not explained solely by D2 blockade and may involve broader dopaminergic, serotonergic, glutamatergic, and cholinergic modulation. CYP1A2 is the main metabolic pathway, with contributions from CYP3A4 and CYP2D6; inflammation, smoking changes, and inhibitors can substantially alter exposure.1,2
Dosing & protocol.
May be taken with or without food. Restarting after an interruption requires retitration to reduce severe hypotension, bradycardia, and syncope risk.
Full safety detail.
Side effects
- Sedation
- Sialorrhea
- Constipation and ileus
- Weight gain
- Hyperglycemia and dyslipidemia
- Orthostatic hypotension
- Tachycardia
- Severe neutropenia
- Seizures, dose-related
- Myocarditis, pericarditis, or cardiomyopathy
- Fever
- Neuroleptic malignant syndrome
- Pulmonary embolism
Contraindications
- Hypersensitivity to clozapine1,2
- Do not initiate when baseline ANC is below prescribing-information thresholds2,3
- History of clozapine-induced agranulocytosis or severe granulocytopenia unless benefits clearly justify specialist-supervised rechallenge1,2
- Paralytic ileus
- Use extreme caution with uncontrolled epilepsy, myocarditis history, severe cardiac disease, or severe constipation
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
1- 1Clozapine for treatment-resistant schizophreniaKane J, Honigfeld G, Singer J, Meltzer H · Archives of General Psychiatry · 1988
Pivotal trial established clozapine efficacy in treatment-resistant schizophrenia compared with chlorpromazine plus benztropine.
Reference material
2- 2CLOZAPINE tablets, US Prescribing InformationURLU.S. National Library of Medicine · DailyMed · 2026
Current labeling describes boxed warnings, ANC thresholds, slow titration, restart instructions, and serious constipation risk.
- 3FDA removes risk evaluation and mitigation strategy (REMS) program for the antipsychotic drug ClozapineURLU.S. Food and Drug Administration · FDA Drug Safety and Availability · 2025
FDA eliminated REMS requirements effective June 13, 2025 while preserving ANC monitoring recommendations in labeling.
Common questions.
Quick answers about Clozapine, drawn from the data on this page.
What is Clozapine?
Clozapine is an atypical antipsychotic reserved for treatment-resistant schizophrenia and for reducing recurrent suicidal behavior in schizophrenia or schizoaffective disorder. It has unique efficacy but multiple boxed warnings, including severe neutropenia, orthostatic hypotension with bradycardia and syncope, seizures, myocarditis or cardiomyopathy, and increased mortality in elderly patients with dementia-related psychosis. ANC monitoring remains required by prescribing information even though FDA removed the Clozapine REMS program effective June 13, 2025.
What is Clozapine used for?
Commonly cited benefits of Clozapine include: Treatment-resistant schizophrenia after inadequate response to standard antipsychotics; Reduction in recurrent suicidal behavior in schizophrenia or schizoaffective disorder; May reduce aggression or severe psychotic symptoms in selected refractory cases. NutriStack rates the overall evidence as strong.
What is a typical dose of Clozapine?
A typical adult dose of Clozapine is Start 12.5 mg once or twice daily and titrate slowly. Common target range is 300-450 mg/day in divided doses; maximum recommended dose is 900 mg/day.. The commonly recommended form is Oral tablet, orally disintegrating tablet, or oral suspension with mandatory ANC monitoring. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Clozapine?
Reported side effects include sedation, sialorrhea, constipation and ileus, weight gain, hyperglycemia and dyslipidemia, orthostatic hypotension. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Clozapine?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Clozapine in NutriStack.
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