Drugs › Substance P/Neurokinin-1 receptor antagonist
Generic name
Aprepitant: adverse event reports filed with FDA
2,486 reports list it as a suspect or interacting product, 2006–2026. Class: Substance P/Neurokinin-1 receptor antagonist. Also reported as Cap Aprepitant, Aprepitant Capsules Usp 80mg.
- 2,486
- reports as suspect product
- 0% of all reports · about 121 a year
- 328
- reports, 12 months to June 2026
- 495 in the 12 months before
- 96.8%
- marked serious by the reporter
- 83.3% across the class
- 30%
- record death among outcomes, as reported
- 745 reports · not verified by FDA
Between January 2006 and June 2026, 2,486 adverse event reports received by FDA list aprepitant, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (4,741) are left out of every figure here.
In the 12 months to June 2026, 328 reports listed it, down 34% from 495 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 121 reports a year and 0% of the 20,646,523 reports in the database, and 28.2% of the reports for the substance P/Neurokinin-1 receptor antagonist class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded fatigue (30.2%), pyrexia (25%) and alopecia (24.3%). A report can list several reactions, so shares add to more than 100%; 576 different terms appear across these reports. Fatigue is recorded in 30.2% of these reports, about the same share as in the median substance P/Neurokinin-1 receptor antagonist drug (30.2%).
96.8% of the reports are marked serious by the reporter (83.3% across the class); 30% record death among the outcomes and 66.4% record hospitalisation, as reported. 56.7% of the reports came from other health professionals, and the largest patient age group is 18 to 44 (31.8%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Aprepitant reports recording the termmedian drug in substance p/neurokinin-1 receptor antagonist
- Fatiguetiredness30.2%750
- Pyrexiafever25%622
- Alopeciahair loss24.3%603
- Hypersensitivityan allergic-type reaction23%571
- Off label useused for a purpose or in a way not on the label22.8%566
- Rashskin rash22.4%557
- Gastrointestinal disorder22.3%555
- Dyspnoeashortness of breath22.3%554
- Hand deformity22.2%552
- Helicobacter infection22.1%549
- Glossodynia21.9%545
- Folliculitis21.8%541
- Impaired healingslow healing21.2%527
- Confusional stateconfusion21%523
- Pruritusitching20.9%519
- Joint swellinga swollen joint20.8%517
- Duodenal ulcer perforation20.6%512
- Sinusitissinus infection20.6%511
- Irritable bowel syndrome20.4%506
- Lower respiratory tract infectiona chest infection20.2%503
- Nasopharyngitisa cold20.1%499
- Infusion related reactiona reaction during or soon after an infusion20%498
- Muscle injury20%498
- Painpain, site not specified20%498
- Synovitis20%498
- Systemic lupus erythematosuslupus, an autoimmune disease20%497
- Hepatic enzyme increasedraised liver enzymes19.8%493
- Swellingswelling19.8%492
- Infectionan infection, type not specified19.5%486
- Stomatitissore mouth19.4%482
Top 30 of 576 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 3 drugs in the substance p/neurokinin-1 receptor antagonist class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 8,823 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 6% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Prophylaxis of nausea and vomiting | 364 | 14.6% |
| Antiemetic supportive care | 98 | 3.9% |
| Vomiting | 86 | 3.5% |
| Supportive care | 81 | 3.3% |
| Nausea | 78 | 3.1% |
| Chemotherapy side effect prophylaxis | 69 | 2.8% |
The indication field is filled in by the reporter and is often blank; shares are of all 2,486 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Aprepitant reports |
|---|---|---|
| Acetaminophen | 1,023 | 41.2% |
| Prednisone | 973 | 39.1% |
| Folic acid | 952 | 38.3% |
| Rituximab | 883 | 35.5% |
| Methotrexate | 880 | 35.4% |
| Sulfasalazine | 866 | 34.8% |
| Desoximetasone | 858 | 34.5% |
| Leflunomide | 836 | 33.6% |
| Cimzia | 829 | 33.3% |
| Orencia | 825 | 33.2% |
Other products listed in reports where Aprepitant is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.
In context
| Measure | Aprepitant | Substance P/Neurokinin-1 receptor antagonist | All reports |
|---|---|---|---|
| Reports as suspect product | 2,486 | 8,823 | 20,646,523 |
| Share of that pool | — | 28.2% | 0% |
| Reports, latest 12 months | 328 | — | 1,332,454 |
| Marked serious | 96.8% | 83.3% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 300 | 219 | 91 |
| Hospitalisation recorded, per 1,000 reports | 664 | 519 | 213 |
| Consumer-filed share | 8% | 15.4% | 45.8% |
| Top term, share of reports | Fatigue 30.2% | median 30.2% | 3.7% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the substance p/neurokinin-1 receptor antagonist class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Emend | brand | 5,750 | 161 | 77.5% |
| Fosaprepitant | generic | 587 | 146 | 82.6% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Aprepitant reports
How many adverse event reports has FDA received for Aprepitant?
2,486 reports list Aprepitant as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 328 of them arrived in the latest 12 months. Another 4,741 list it only as a concomitant medication.
What reactions are recorded in Aprepitant reports?
fatigue (30.2%), pyrexia (25%), alopecia (24.3%), hypersensitivity (23%) and off label use (22.8%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Aprepitant was responsible.
How serious are the reports?
96.8% are marked serious by the reporter. Among the outcomes recorded, 30% of reports include death and 66.4% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
other health professional (56.7%), physician (21.4%) and pharmacist (12.6%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Aprepitant rising?
328 reports in the 12 months to June 2026, down 34% from 495 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Aprepitant was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Aprepitant?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Aprepitant as a suspect or interacting product; reports listing it only as a concomitant medication (4,741) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.