FDA Adverse Events Reports (FAERS) Summary for CLOZAPINE

These tables and charts are based on 81,533 total reports for CLOZAPINE (CLOZAPINE) received by the FDA Adverse Event Reporting System (FAERS) from 2004 through July 30, 2026.

This FAERS total includes 80,693 pharmaceutical company-submitted and non-U.S. FAERS reports and 840 U.S. consumer or healthcare provider-submitted MedWatch reports. Adverse events listed on this page represent serious and sometimes rare adverse events reported to pharmaceutical companies, and often do not represent typical side effects for the medication. Find common side effects in the most recent official drug label.

For a separate summary of the 840 U.S. reports filed via the FDA MedWatch voluntary reporting system, view our FDA MedWatch CLOZAPINE summary report. (See notes section below for explanation of FDA’s mandatory and voluntary reporting system.)

CLOZAPINE Total Reports

Top Countries Reporting

Outcomes for Reports

Serious: 75696
Not Serious: 5834
Note: A serious outcome means the adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition.

Top Companies Reporting

Safety-Related FDA Updates

CLOZARIL (CLOZAPINE) Rx Drug:
Strengthening an existing warning that constipation caused by the schizophrenia medicine clozapine (Clozaril, Fazaclo ODT, Versacloz) can progress to serious bowel problems Drug Safety CommunicationDrug Safety Communication FDA Safety Communication

CLOZAPINE (CLOZAPINE) Rx Drug:
Strengthening an existing warning that constipation caused by the schizophrenia medicine clozapine (Clozaril, Fazaclo ODT, Versacloz) can progress to serious bowel problemsDrug Safety Communication FDA Safety Communication

Clozapine (CLOZAPINE) Rx Drug:
REMS has been eliminated in Feb. 2025 in order to decrease the burden on the health care delivery system and improve access. Risk still exists: monitor ANC because of risk of neutropenia.Shared FDA Risk Evaluation and Mitigation Strategy REMS

VERSACLOZ (CLOZAPINE) Rx Drug:
Added the risk of Pericarditis in addition to myocarditis. Symptoms of myocarditis or percarditis can also include heart palpitations. Safety-related Labeling Changes

FAZACLO ODT (CLOZAPINE) Rx Drug:
Safety-related Labeling Changes

CLOZARIL (CLOZAPINE) Rx Drug:
Added the risk of Pericarditis in addition to myocarditis. Symptoms of myocarditis or percarditis can also include heart palpitations. Added side effect of fecal incontinence. Safety-related Labeling Changes

For serious adverse events, report them to the FDA by contacting the drug manufacturer or report directly through the MedWatch voluntary reporting form.

Notes

Events listed on this page represent serious and often rare adverse events reported to pharmaceutical companies, and do not represent typical side effects for the medication. Find common side effects on the most recent official drug label This report, created by AskaPatient.com, is derived from the cases for CLOZAPINE reported to the United States Food and Drug Administration (FDA) FDA Safety Information and Adverse Event Reporting System (FAERS) and obtained from Open FDA. Data was last updated with reports received through July 30, 2026.

This summary includes ALL reports where the drug is a "primary OR secondary OR suspected interacting" drug. Typically, reports are filed for the most serious type or "event" and do not represent incidental or minor side effects. The majority of these reports are mandatory reports submitted by pharmaceutical companies, who receive complaints from consumers. The reactions, side effects, or "adverse events," represent up to the 20 most frequently occuring events in the database for a drug related to the event. This report also features counts of latest known outcomes associated with reported side effects, but does not provide the specific outcomes for specific adverse events.

Adverse Event Reports are submitted to the FAERS database by pharmaceutical companies (mandatory reporting is required by manufacturers, distributors, or importers). Health care providers such as doctors (voluntary reporting), and patients themselves (voluntary reporting) report to the FDA directly through the MedWatch program. Those MedWatch reports are coded and included in the FAERS database. This report mainly consists of the mandatory reports, because the MedWatch reports are a small percentage (3 - 5%) of total reports. Link to the MedWatch summary report at the top of the page for a summary of the directly reported (voluntary) adverse events for this drug.The number of reports included here might differ somewhat from the number of reports in the downloadable quarterly FAERS reports and in the online FAERS dashboard, due to lags in reporting, drug name differences, duplicates, and other factors. Open FDA states that it only includes the most recent version of a case report. It also adds the disclaimer: "Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated."

FDA uses the "MedDRA" classification system to describe reported adverse reactions. MedDRA is a standardized medical terminology that facilitates sharing of regulatory information internationally. In some cases, "patient friendly" terms for the layman designated by MedDRA have been substituted for medical jargon. Please contact us with questions or comments about this report.