CLOZAPINE

85/100 · Critical

Manufactured by HLS Therapeutics (USA), Inc.

High Safety Concerns with Clozapine Due to Serious Adverse Reactions

207,229 FDA adverse event reports analyzed

Last updated: 2026-05-12

About CLOZAPINE

CLOZAPINE is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by HLS Therapeutics (USA), Inc.. Based on analysis of 207,229 FDA adverse event reports, CLOZAPINE has a safety score of 85 out of 100. This score indicates a relatively favorable safety profile, with fewer or less severe adverse events compared to many other tracked medications. The most commonly reported adverse reactions for CLOZAPINE include NEUTROPENIA, HOSPITALISATION, DEATH, SCHIZOPHRENIA, WHITE BLOOD CELL COUNT INCREASED. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for CLOZAPINE.

AI Safety Analysis

Clozapine has a safety concern score of 85 out of 100, placing it in the high concern category based on analysis of FDA adverse event data. The FDA has received approximately 207,229 adverse event reports for this medication, which is primarily manufactured by Hls Therapeutics (Usa), Inc..

The most commonly reported adverse events include Neutropenia, Hospitalisation, Death. Of classified reports, 94.7% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Neutropenia and agranulocytosis are the most serious and frequent adverse reactions.

Hospitalization and death are common, indicating severe health impacts. Drug interactions and overuse are significant safety signals.

Patients taking Clozapine should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Clozapine requires strict monitoring for neutropenia and agranulocytosis, and caution is advised with other medications due to potential interactions. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.

Safety Score: 85/100

Clozapine received a safety concern score of 85/100 (high concern). This is based on a 94.7% serious event ratio across 121,298 classified reports. The score accounts for 207,229 total adverse event reports and 100 distinct reaction types. This high score reflects a significant proportion of serious adverse events in the reporting data.

Top Adverse Reactions

NEUTROPENIA18,655 reports
HOSPITALISATION12,101 reports
DEATH11,402 reports
SCHIZOPHRENIA4,547 reports
WHITE BLOOD CELL COUNT INCREASED4,448 reports
WHITE BLOOD CELL COUNT DECREASED4,368 reports
NEUTROPHIL COUNT INCREASED4,117 reports
DRUG INEFFECTIVE3,865 reports
MALAISE3,705 reports
OFF LABEL USE3,565 reports
PNEUMONIA3,191 reports
TREATMENT NONCOMPLIANCE3,091 reports
NEUTROPHIL COUNT DECREASED3,087 reports
DRUG INTERACTION3,057 reports
PSYCHOTIC DISORDER3,037 reports
HAEMOGLOBIN DECREASED3,029 reports
TACHYCARDIA2,765 reports
FALL2,625 reports
GRANULOCYTOPENIA2,616 reports
LEUKOPENIA2,574 reports
PYREXIA2,552 reports
NEUTROPHILIA2,464 reports
CONSTIPATION2,296 reports
SEDATION2,238 reports
SOMNOLENCE2,193 reports
MENTAL IMPAIRMENT2,189 reports
MYOCARDITIS2,104 reports
AGRANULOCYTOSIS2,046 reports
VOMITING2,012 reports
CONFUSIONAL STATE1,915 reports
OVERDOSE1,844 reports
SALIVARY HYPERSECRETION1,773 reports
TOXICITY TO VARIOUS AGENTS1,765 reports
THERAPY INTERRUPTED1,756 reports
WEIGHT INCREASED1,745 reports
C REACTIVE PROTEIN INCREASED1,720 reports
THROMBOCYTOPENIA1,691 reports
ANAEMIA1,689 reports
DYSPNOEA1,660 reports
LEUKOCYTOSIS1,628 reports
COVID 191,588 reports
PLATELET COUNT DECREASED1,582 reports
ANTIPSYCHOTIC DRUG LEVEL INCREASED1,571 reports
HYPOTENSION1,553 reports
URINARY TRACT INFECTION1,553 reports
CONDITION AGGRAVATED1,488 reports
DIZZINESS1,471 reports
DIFFERENTIAL WHITE BLOOD CELL COUNT ABNORMAL1,449 reports
FATIGUE1,440 reports
SUICIDE ATTEMPT1,426 reports
LOWER RESPIRATORY TRACT INFECTION1,423 reports
ELECTROCARDIOGRAM QT PROLONGED1,421 reports
MENTAL DISORDER1,376 reports
NEUROLEPTIC MALIGNANT SYNDROME1,305 reports
AGITATION1,292 reports
HALLUCINATION, AUDITORY1,284 reports
DIARRHOEA1,277 reports
DYSKINESIA1,263 reports
NAUSEA1,258 reports
HALLUCINATION1,250 reports
INFECTION1,233 reports
ANXIETY1,223 reports
SEPSIS1,209 reports
AGGRESSION1,195 reports
GENERAL PHYSICAL HEALTH DETERIORATION1,188 reports
PRODUCT DOSE OMISSION ISSUE1,156 reports
RED BLOOD CELL COUNT DECREASED1,140 reports
HAEMATOCRIT DECREASED1,127 reports
CHEST PAIN1,095 reports
SEIZURE1,066 reports
BLOOD CREATINE PHOSPHOKINASE INCREASED1,061 reports
DELIRIUM1,057 reports
TREMOR1,057 reports
SUICIDAL IDEATION1,055 reports
MYOCARDIAL INFARCTION1,046 reports
BLOOD GLUCOSE INCREASED1,044 reports
LOSS OF CONSCIOUSNESS1,043 reports
DELUSION1,022 reports
DRUG LEVEL INCREASED1,019 reports
ASTHENIA999 reports
DIABETES MELLITUS998 reports
TROPONIN INCREASED973 reports
PNEUMONIA ASPIRATION968 reports
WEIGHT DECREASED968 reports
PLATELET COUNT INCREASED967 reports
EOSINOPHIL COUNT DECREASED931 reports
THERAPY CESSATION912 reports
EOSINOPHILIA909 reports
HYPERTENSION901 reports
ABDOMINAL PAIN898 reports
DYSTONIA878 reports
PRODUCT USE IN UNAPPROVED INDICATION862 reports
LYMPHOCYTE COUNT DECREASED853 reports
CARDIAC ARREST852 reports
SINUS TACHYCARDIA852 reports
CHRONIC OBSTRUCTIVE PULMONARY DISEASE831 reports
HEART RATE INCREASED825 reports
ABNORMAL BEHAVIOUR817 reports
GAIT DISTURBANCE802 reports
ORTHOSTATIC HYPOTENSION802 reports

Key Safety Signals

  • Neutropenia and agranulocytosis
  • Hospitalization and death
  • Drug interactions

Patient Demographics

Adverse event reports by sex: Male: 65,492, Female: 41,716, Unknown: 209. The most frequently reported age groups are age 56 (1,565 reports), age 47 (1,511 reports), age 58 (1,507 reports). These demographics reflect reporting patterns and may not represent the full patient population.

Report Outcomes

Out of 121,298 classified reports for CLOZAPINE:

  • Serious: 114,824 reports (94.7%) — includes hospitalization, disability, life-threatening events, or death
  • Non-Serious: 6,474 reports (5.3%)
Serious 94.7%Non-Serious 5.3%

The FDA classifies an adverse event as “serious” if it results in death, hospitalization, disability, congenital anomaly, or requires intervention to prevent permanent damage.

Demographics Breakdown

Reports by Sex

Male65,492 (61.0%)
Female41,716 (38.8%)
Unknown209 (0.2%)

Reports by Age

Age 561,565 reports
Age 471,511 reports
Age 581,507 reports
Age 531,482 reports
Age 591,474 reports
Age 541,472 reports
Age 501,470 reports
Age 521,467 reports
Age 511,466 reports
Age 491,462 reports
Age 441,453 reports
Age 551,449 reports
Age 361,425 reports
Age 571,406 reports
Age 321,385 reports
Age 431,385 reports
Age 481,385 reports
Age 621,376 reports
Age 451,370 reports
Age 461,351 reports

Demographics reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.

Drug Interactions & Warnings

Clozapine requires strict monitoring for neutropenia and agranulocytosis, and caution is advised with other medications due to potential interactions.

What You Should Know

If you are taking Clozapine, here are important things to know. The most commonly reported side effects include neutropenia, hospitalisation, death, schizophrenia, white blood cell count increased. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Regularly monitor blood counts and report any signs of infection or fever. Do not stop or change the dosage without consulting a healthcare provider. If you experience a serious adverse reaction, seek emergency medical attention immediately or call 911. You can report side effects to the FDA's MedWatch program at 1-800-FDA-1088.

Regulatory Context

Clozapine is subject to strict FDA oversight and requires regular blood tests to monitor for severe side effects.

Frequently Asked Questions

How many adverse event reports has the FDA received for Clozapine?

The FDA has received approximately 207,229 adverse event reports associated with Clozapine. These reports come from healthcare professionals, consumers, and manufacturers through the FDA Adverse Event Reporting System (FAERS). Note that the number of reports does not directly indicate the frequency of side effects, as adverse events are voluntarily reported and may be underrepresented.

What are the most commonly reported side effects of Clozapine?

The most frequently reported adverse events for Clozapine include Neutropenia, Hospitalisation, Death, Schizophrenia, White Blood Cell Count Increased. By volume, the top reported reactions are: Neutropenia (18,655 reports), Hospitalisation (12,101 reports), Death (11,402 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Clozapine.

What percentage of Clozapine adverse event reports are serious?

Out of 121,298 classified reports, 114,824 (94.7%) were classified as serious and 6,474 as non-serious. The FDA classifies an event as "serious" if it results in death, hospitalization, disability, or other medically significant outcomes. A higher serious-event ratio warrants closer attention but does not necessarily mean the drug is unsafe.

Who reports adverse events for Clozapine (by sex)?

Adverse event reports for Clozapine break down by patient sex as follows: Male: 65,492, Female: 41,716, Unknown: 209. This distribution reflects reporting patterns rather than actual risk differences between groups. Reporting rates can be influenced by prescribing patterns, disease demographics, and reporting behavior.

What age groups report the most side effects for Clozapine?

The most frequently reported age groups for Clozapine adverse events are: age 56: 1,565 reports, age 47: 1,511 reports, age 58: 1,507 reports, age 53: 1,482 reports, age 59: 1,474 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.

Who manufactures Clozapine?

The primary manufacturer associated with Clozapine adverse event reports is Hls Therapeutics (Usa), Inc.. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.

What other side effects have been reported for Clozapine?

Beyond the most common reactions, other reported adverse events for Clozapine include: White Blood Cell Count Decreased, Neutrophil Count Increased, Drug Ineffective, Malaise, Off Label Use. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.

How do I report a side effect from Clozapine?

You can report adverse events from Clozapine to the FDA through their MedWatch program at www.fda.gov/medwatch, by calling 1-800-FDA-1088, or by completing Form FDA 3500. Healthcare professionals, consumers, and manufacturers can all submit reports. Reporting helps the FDA monitor drug safety after approval.

What is Clozapine's safety score and what does it mean?

Clozapine has a safety concern score of 85 out of 100 (high concern). This score is calculated from the ratio of serious to non-serious adverse events, the diversity of reported reactions, and the overall volume of reports relative to usage. Neutropenia and agranulocytosis are the most serious and frequent adverse reactions.

What are the key safety signals for Clozapine?

Key safety signals identified in Clozapine's adverse event data include: Neutropenia and agranulocytosis. Hospitalization and death. Drug interactions. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.

Does Clozapine interact with other drugs?

Clozapine requires strict monitoring for neutropenia and agranulocytosis, and caution is advised with other medications due to potential interactions. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Clozapine.

What should patients know before taking Clozapine?

Regularly monitor blood counts and report any signs of infection or fever. Do not stop or change the dosage without consulting a healthcare provider.

Are Clozapine side effects well-documented?

Clozapine has 207,229 adverse event reports on file with the FDA. Hospitalization and death are common, indicating severe health impacts. The volume of reports for Clozapine reflects both the drug's usage level and the vigilance of the reporting community.

What is the FDA's position on Clozapine?

Clozapine is subject to strict FDA oversight and requires regular blood tests to monitor for severe side effects. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.

Related Drugs

Drugs related to CLOZAPINE based on therapeutic use, drug class, or shared indications:

ClozapineImmunosuppressantsAntibioticsAntifungalsAntivirals
Important Disclaimer: This content is generated by AI analysis of FDA adverse event reports and is provided for informational purposes only. It is not medical advice. Adverse event reports submitted to the FDA do not prove that a medication caused the reported side effect. Always consult your healthcare provider before starting, stopping, or changing any medication. If you experience a serious side effect, contact your doctor or call 911 immediately.