Clozarilclozapine
According to the FDA label: Clozapine orally disintegrating tablets (Clozapine ODT) is an atypical antipsychotic indicated for: Treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment.
123,170 adverse event reports submitted to the FDA (2001–2026)
Top Reported Adverse Events
The most frequently reported events in association with Clozaril in the FAERS database. These are events reported by patients taking this medication, not necessarily caused by it. A single report may include multiple events.
Show these terms with plain-language definitions
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Neutropenia 18,813 reports
A low level of neutrophils, a type of white blood cell that fights infection.
Full definition in the glossary →Hospitalisation 12,257 reports
A report that the person was admitted to a hospital. This records that a hospital stay occurred, which is one way the seriousness of an event is tracked. Also spelled hospitalization in American English.
Full definition in the glossary →Death 11,739 reports
A report that the person died. A death appearing in reports for a drug does not mean the drug caused it. Reports record that a death occurred while the medication was being used, which can happen for many unrelated reasons.
Full definition in the glossary →Schizophrenia 4,607 reports
A mental health condition that affects how a person thinks, feels, and perceives reality. It often appears in reports as a condition being treated.
Full definition in the glossary →- White Blood Cell Count Increased 4,478 reports
White Blood Cell Count Decreased 4,431 reports
A blood test result showing a low level of white blood cells, which help fight infection.
Full definition in the glossary →- Neutrophil Count Increased 4,148 reports
Drug Ineffective 3,910 reports
A report that the medication did not work as expected for the person taking it. This is a reporting category, not a sign the drug is defective. It simply means someone felt it was not helping their condition.
Full definition in the glossary →Malaise 3,773 reports
A general feeling of being unwell or uncomfortable, without a specific symptom.
Full definition in the glossary →Off Label Use 3,686 reports
Using a medication for a condition or in a way that the FDA has not officially approved. This is common and often legal, and a report of it does not mean something went wrong. Doctors sometimes prescribe drugs off label based on their judgment.
Full definition in the glossary →Pneumonia 3,222 reports
An infection that inflames the air sacs in the lungs, which can cause cough, fever, and difficulty breathing.
Full definition in the glossary →Treatment Noncompliance 3,181 reports
A report that a person did not take a treatment as prescribed. This is a reporting category describing what happened, not a judgment about the person.
Full definition in the glossary →Neutrophil Count Decreased 3,138 reports
A blood test result showing a low level of neutrophils, a type of infection-fighting white blood cell. This is the lab-measurement version of neutropenia.
Full definition in the glossary →Drug Interaction 3,095 reports
A report that two or more medications may have affected each other when taken together.
Full definition in the glossary →Haemoglobin Decreased 3,084 reports
A blood test result showing a low level of haemoglobin, the protein in red blood cells that carries oxygen. This is closely related to anaemia. Also spelled hemoglobin in American English.
Full definition in the glossary →
Ranked by frequency of reports, not severity. The most-reported event is not necessarily the most dangerous or the most common in patients taking this drug.
Who Is Reporting
Demographics of patients in FAERS reports that included this information. Not all reports include patient demographics.
By Sex
View reporter sex data as a table
| Sex | Reports |
|---|---|
| Male | 66,553 |
| Female | 42,449 |
| Unknown | 209 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 2,105 |
| 18-34 | 17,074 |
| 35-49 | 20,591 |
| 50-64 | 21,525 |
| 65-74 | 8,701 |
| 75+ | 4,292 |
This shows who filed reports, reflecting who takes this drug and who tends to report, not who is at greatest risk.
Reported Outcomes
Outcomes recorded in FAERS reports that included Clozaril. A single report may involve multiple reactions, each with a different outcome. These categories are defined by FDA reporting guidelines, not by PillSignal.
View outcome data as a table
| Outcome | Reports |
|---|---|
| Other Serious | 68,485 |
| Hospitalization | 53,796 |
| Death | 21,909 |
| Non-Serious | 6,588 |
| Life-Threatening | 6,504 |
| Disability | 1,214 |
Serious outcomes are far more likely to be reported than mild ones, so this overstates how often outcomes are serious. A recorded death does not mean the drug caused it.
Report Volume Over Time
Number of FAERS reports received per quarter for Clozaril. Changes in volume may reflect shifts in prescribing rates, media attention, or reporting behavior, not changes in the medication's safety profile.
View report trend as a table
| Year | Reports |
|---|---|
| 2001 | 1 |
| 2002 | 4 |
| 2003 | 5 |
| 2004 | 1,707 |
| 2005 | 1,588 |
| 2006 | 2,443 |
| 2007 | 924 |
| 2008 | 932 |
| 2009 | 1,994 |
| 2010 | 2,874 |
| 2011 | 5,629 |
| 2012 | 4,175 |
| 2013 | 3,012 |
| 2014 | 3,388 |
| 2015 | 4,170 |
| 2016 | 4,537 |
| 2017 | 7,274 |
| 2018 | 6,820 |
| 2019 | 7,450 |
| 2020 | 8,078 |
| 2021 | 7,360 |
| 2022 | 13,919 |
| 2023 | 13,134 |
| 2024 | 11,702 |
| 2025 | 8,273 |
| 2026 (partial) | 1,777 |
The steep increase around 2004 reflects the FDA's move to electronic submission, not a change in this drug's safety. Trends track reporting volume, not risk.
Medications commonly reported with Clozaril
In FDA adverse event reports that mention Clozaril, these medications appeared most often in the same report.
- Olanzapine (8,421 reports)
- Aripiprazole (6,827 reports)
- Quetiapine (6,288 reports)
- Risperidone (6,129 reports)
- Aripiprazole Orally Disintegrating (4,904 reports)
This reflects co-occurrence in submitted reports, not evidence of drug interaction or combined risk. People often report several medications taken for the same condition or for unrelated reasons. Talk to a doctor or pharmacist about your specific medications.
Related Drugs
Other medications with similar adverse event profiles in FDA FAERS reports.
Data Source
This data is sourced from the FDA's Adverse Event Monitoring System (AEMS), formerly FAERS, via the OpenFDA API. PillSignal is not affiliated with the FDA.
View this data on the FDA website →Data last updated: June 2026