Herceptintrastuzumab
According to the FDA label: Herceptin is a HER2/neu receptor antagonist indicated in adults for: The treatment of HER2-overexpressing breast cancer. ( 1.1 , 1.2 ) The treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma. ( 1.3 ) Select patients for therapy based on an FDA-authorized companion diagnostic for Herceptin ( 1 , 2.2 ).
66,343 adverse event reports submitted to the FDA (2004–2026)
Top Reported Adverse Events
The most frequently reported events in association with Herceptin 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.
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Diarrhoea 6,516 reports
Loose or watery bowel movements, often frequent. Also spelled diarrhea in American English.
Full definition in the glossary → See all drugs reporting this event →Alopecia 4,989 reports
Nausea 4,435 reports
The feeling of sickness in your stomach that often comes before vomiting.
Full definition in the glossary → See all drugs reporting this event →Fatigue 4,306 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Off Label Use 4,127 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 →Death 3,575 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 →Disease Progression 3,486 reports
A report that the underlying condition being treated got worse over time. This describes the course of the illness, not necessarily an effect of the drug.
Full definition in the glossary →Vomiting 2,949 reports
Throwing up the contents of the stomach.
Full definition in the glossary → See all drugs reporting this event →Myelosuppression 2,911 reports
A decrease in the bone marrow's production of blood cells, which can lower red cells, white cells, and platelets. Common with some cancer treatments.
Full definition in the glossary →Dyspnoea 2,739 reports
Shortness of breath or difficulty breathing. Also spelled dyspnea in American English.
Full definition in the glossary → See all drugs reporting this event →Pyrexia 2,497 reports
The medical term for fever, meaning a raised body temperature.
Full definition in the glossary → See all drugs reporting this event →Asthenia 2,268 reports
Physical weakness or lack of strength.
Full definition in the glossary →Neutropenia 2,157 reports
A low level of neutrophils, a type of white blood cell that fights infection.
Full definition in the glossary →Neuropathy Peripheral 2,088 reports
Damage to the nerves outside the brain and spinal cord, often causing numbness, tingling, or pain in the hands and feet.
Full definition in the glossary →Pain 2,046 reports
A general report of physical discomfort, used when no more specific location is given.
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 |
|---|---|
| Female | 53,445 |
| Male | 3,925 |
| Unknown | 472 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 582 |
| 18-34 | 1,785 |
| 35-49 | 11,008 |
| 50-64 | 18,193 |
| 65-74 | 7,938 |
| 75+ | 3,205 |
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 Herceptin. 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 | 36,975 |
| Hospitalization | 19,216 |
| Non-Serious | 9,716 |
| Death | 8,065 |
| Life-Threatening | 2,711 |
| Disability | 1,430 |
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 Herceptin. 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 |
|---|---|
| 2004 | 371 |
| 2005 | 377 |
| 2006 | 530 |
| 2007 | 587 |
| 2008 | 654 |
| 2009 | 973 |
| 2010 | 1,225 |
| 2011 | 1,190 |
| 2012 | 2,644 |
| 2013 | 2,889 |
| 2014 | 2,389 |
| 2015 | 2,682 |
| 2016 | 2,839 |
| 2017 | 4,452 |
| 2018 | 5,684 |
| 2019 | 4,958 |
| 2020 | 5,106 |
| 2021 | 4,898 |
| 2022 | 4,742 |
| 2023 | 5,016 |
| 2024 | 6,901 |
| 2025 | 4,327 |
| 2026 (partial) | 909 |
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 Herceptin
In FDA adverse event reports that mention Herceptin, these medications appeared most often in the same report.
- Pertuzumab (22,775 reports)
- Docetaxel (16,041 reports)
- Paclitaxel (10,352 reports)
- Paclitaxel Aibumin-bound (9,775 reports)
- Capecitabine (9,146 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