Two medicines, side by side
Chlorpromazine vs clozapine
Chlorpromazine and clozapine are both labeled for schizophrenia. Drugs@FDA records approvals of chlorpromazine since 1957 and of clozapine since 1989. Pharmacies paid $0.552 per chlorpromazine 100 mg tablet and $0.610 per clozapine 100 mg tablet (NADAC, October 7, 2026). In FDA's classes, chlorpromazine is a phenothiazine and clozapine an atypical antipsychotic.
Check it at the source: the chlorpromazine FDA label on DailyMed (effective May 12, 2026); the clozapine FDA label on DailyMed (effective June 6, 2025).
Highlights of the chlorpromazine record
Chlorpromazine (Thorazine) · label of May 12, 2026
Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of seventeen placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients.
Used for
From the label: indicationsFor the management of manifestations of psychotic disorders. For the treatment of schizophrenia. To control nausea and vomiting. For relief of restlessness and apprehension before surgery. For acute intermittent porphyria. As an adjunct in the treatment of tetanus. To control the manifestations of the manic type of manic-depressive illness. For relief of intractable hiccups. […]
On the market
- Earliest approval on file
- September 18, 1957
- Generic labelers
- 33 labelers
- Pharmacy cost
- $0.552 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 25
Highlights of the clozapine record
Clozapine (Clozaril) · label of June 6, 2025
SEVERE NEUTROPENIA; ORTHOSTATIC HYPOTENSION, BRADYCARDIA, AND SYNCOPE; SEIZURE; MYOCARDITIS, PERICARDITIS AND CARDIOMYOPATHY; INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS Severe Neutropenia CLOZARIL has caused severe neutropenia which is associated with an increased risk of serious and potentially fatal infections. Prior to initiating CLOZARIL treatment, obtain baseline ANC(s).
Used for
From the label: indicationsCLOZARIL is an atypical antipsychotic indicated for: • Treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. […]
On the market
- Earliest approval on file
- September 26, 1989
- Generic labelers
- 11 labelers
- Pharmacy cost
- $0.610 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 4
Source: FDA drug labels via openFDA (Chlorpromazine label of May 12, 2026, Clozapine label of June 6, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do chlorpromazine and clozapine differ on the record?
In FDA's classes, chlorpromazine is a phenothiazine and clozapine an atypical antipsychotic.
Both labels carry a boxed warning; the records quote them.
Generics: chlorpromazine since 1972; clozapine since 1996 (Drugs@FDA).
| Chlorpromazine | Clozapine | |
|---|---|---|
| Labeled for | Schizophrenia, Nausea and vomiting | Schizophrenia |
| Pharmacologic class | Phenothiazine | Atypical Antipsychotic |
| How it works (label) | n/a | The mechanism of action of clozapine is unknown. |
| Half-life (label) | n/a | The mean elimination half-life of clozapine after a single 75 mg dose was 8 hours (range: 4 to 12 hours), compared to a mean elimination half-life of 12 hours (range: 4 to 66 hours), after achieving steady state with … |
| Earliest approval on file (Drugs@FDA) | September 18, 1957 | September 26, 1989 |
| First generic approved | March 16, 1972 | August 30, 1996 |
| Generic labelers (NDC) | 33 labelers | 11 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.552 per tablet (Chlorpromazine 100 mg tablet) | $0.610 per tablet (Clozapine 100 mg tablet) |
| 12-month price change | -27% | +5% |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 25 | 4 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 7,098 | 124,829 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
Do their labels mention each other?
Clozapine label, warnings and precautionsLaboratory Parameter: Fasting Glucose; Category Change (at least once) from baseline: Normal (<100 mg/dL) to High (≥126 mg/dL); Treatment Arm: Chlorpromazine; N: 135; n (%): 14 (10)
Source: FDA drug labels via openFDA
What do the labels say about using others of their kind?
Clozapine label, warnings and precautionsWhen possible, avoid use with other anticholinergic drugs and use with caution in patients with a current diagnosis or prior history of constipation, urinary retention, clinically significant prostatic hypertrophy, or other conditions in which anticholinergic effects can lead to significant adverse reactions.
Source: FDA drug labels via openFDA
What next?
- Alternatives to chlorpromazine
- every medicine labeled for the same conditions