85/100 · Critical
Manufactured by AstraZeneca Pharmaceuticals LP
Fulvestrant Adverse Events Show High Seriousness and Diverse Reactions
86,552 FDA adverse event reports analyzed
Last updated: 2026-05-12
FULVESTRANT is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by AstraZeneca Pharmaceuticals LP. Based on analysis of 86,552 FDA adverse event reports, FULVESTRANT 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 FULVESTRANT include FATIGUE, MALIGNANT NEOPLASM PROGRESSION, NAUSEA, DEATH, DIARRHOEA. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for FULVESTRANT.
Fulvestrant 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 86,552 adverse event reports for this medication, which is primarily manufactured by Astrazeneca Pharmaceuticals Lp.
The most commonly reported adverse events include Fatigue, Malignant Neoplasm Progression, Nausea. Of classified reports, 80.3% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Fulvestrant reports a high percentage of serious adverse events (80.3%).
The most common reactions include fatigue, nausea, and disease progression. Neutropenia and other hematological issues are frequently reported.
Patients taking Fulvestrant should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Fulvestrant can cause severe hematological issues and disease progression, and patients should be monitored closely for these adverse events. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.
Fulvestrant received a safety concern score of 85/100 (high concern). This is based on a 80.3% serious event ratio across 31,602 classified reports. The score accounts for 86,552 total adverse event reports and 100 distinct reaction types. This high score reflects a significant proportion of serious adverse events in the reporting data.
Adverse event reports by sex: Female: 29,273, Male: 331, Unknown: 41. The most frequently reported age groups are age 70 (731 reports), age 66 (708 reports), age 60 (694 reports). These demographics reflect reporting patterns and may not represent the full patient population.
Out of 31,602 classified reports for FULVESTRANT:
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 reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.
Fulvestrant can cause severe hematological issues and disease progression, and patients should be monitored closely for these adverse events.
If you are taking Fulvestrant, here are important things to know. The most commonly reported side effects include fatigue, malignant neoplasm progression, nausea, death, diarrhoea. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Patients should report any new or worsening symptoms to their healthcare provider immediately. Regular blood tests are recommended to monitor for hematological issues. 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.
The FDA continues to monitor Fulvestrant for safety, and updates will be provided as necessary based on ongoing reviews.
The FDA has received approximately 86,552 adverse event reports associated with Fulvestrant. 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.
The most frequently reported adverse events for Fulvestrant include Fatigue, Malignant Neoplasm Progression, Nausea, Death, Diarrhoea. By volume, the top reported reactions are: Fatigue (4,023 reports), Malignant Neoplasm Progression (3,984 reports), Nausea (2,886 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Fulvestrant.
Out of 31,602 classified reports, 25,376 (80.3%) were classified as serious and 6,226 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.
Adverse event reports for Fulvestrant break down by patient sex as follows: Female: 29,273, Male: 331, Unknown: 41. 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.
The most frequently reported age groups for Fulvestrant adverse events are: age 70: 731 reports, age 66: 708 reports, age 60: 694 reports, age 63: 678 reports, age 65: 643 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.
The primary manufacturer associated with Fulvestrant adverse event reports is Astrazeneca Pharmaceuticals Lp. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.
Beyond the most common reactions, other reported adverse events for Fulvestrant include: Neutropenia, Neoplasm Progression, White Blood Cell Count Decreased, Metastases To Bone, Asthenia. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.
You can report adverse events from Fulvestrant 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.
Fulvestrant 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. Fulvestrant reports a high percentage of serious adverse events (80.3%).
Key safety signals identified in Fulvestrant's adverse event data include: High rate of serious adverse events (25,376 out of 31,602, 80.3%).. Multiple hematological issues like neutropenia and anemia are common.. Disease progression and metastases are frequently reported.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.
Fulvestrant can cause severe hematological issues and disease progression, and patients should be monitored closely for these adverse events. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Fulvestrant.
Patients should report any new or worsening symptoms to their healthcare provider immediately. Regular blood tests are recommended to monitor for hematological issues.
Fulvestrant has 86,552 adverse event reports on file with the FDA. The most common reactions include fatigue, nausea, and disease progression. The volume of reports for Fulvestrant reflects both the drug's usage level and the vigilance of the reporting community.
The FDA continues to monitor Fulvestrant for safety, and updates will be provided as necessary based on ongoing reviews. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.
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