Reported Reactions

Drugs

Product name as reported

Fentora: adverse event reports filed with FDA

24,360 reports list it as a suspect or interacting product, 2006–2025.

24,360
reports as suspect product
0.1% of all reports · about 1,234 a year
1
reports, 12 months to June 2026
4 in the 12 months before
96.8%
marked serious by the reporter
57.4% across all reports
80.4%
record death among outcomes, as reported
19,585 reports · not verified by FDA

24,360 adverse event reports received by FDA list the product name "Fentora" as reporters wrote it as a suspect or interacting product, from October 2006 to July 2025. A further 198 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 1 report listed it, down 75% from 4 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 1,234 reports a year and 0.1% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

The reactions recorded most often are death (47.2%), toxicity to various agents (37.3%) and overdose (22.4%). A report can list several reactions, so shares add to more than 100%; 238 different terms appear across these reports. Death is recorded in 47.2% of these reports, against 4.1% of all reports in the database.

96.8% of the reports are marked serious by the reporter; 80.4% record death among the outcomes and 9.6% record hospitalisation, as reported. 80.6% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (0.8%). 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

024Jul 2021: 0Aug 2021: 0Sep 2021: 2Oct 2021: 0Nov 2021: 2Dec 2021: 42022Jan 2022: 0Feb 2022: 0Mar 2022: 0Apr 2022: 0May 2022: 0Jun 2022: 1Jul 2022: 0Aug 2022: 0Sep 2022: 0Oct 2022: 0Nov 2022: 0Dec 2022: 02023Jan 2023: 1Feb 2023: 0Mar 2023: 0Apr 2023: 0May 2023: 0Jun 2023: 1Jul 2023: 0Aug 2023: 0Sep 2023: 0Oct 2023: 0Nov 2023: 0Dec 2023: 12024Jan 2024: 0Feb 2024: 0Mar 2024: 0Apr 2024: 0May 2024: 3Jun 2024: 0Jul 2024: 2Aug 2024: 0Sep 2024: 0Oct 2024: 1Nov 2024: 0Dec 2024: 02025Jan 2025: 0Feb 2025: 0Mar 2025: 0Apr 2025: 0May 2025: 1Jun 2025: 0Jul 2025: 1Aug 2025: 0Sep 2025: 0Oct 2025: 0Nov 2025: 0Dec 2025: 02026Jan 2026: 0Feb 2026: 0Mar 2026: 0Apr 2026: 0May 2026: 0Jun 2026: 0

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

010,28920,5782006: 120062007: 342008: 15020082009: 1522010: 11820102011: 892012: 13420122013: 1642014: 18720142015: 1352016: 9920162017: 1,7452018: 20,57820182019: 382020: 66120202021: 632022: 120222023: 32024: 620242025: 2

Reactions recorded in the reports

share of Fentora reports recording the termall reports in the database

  1. Deaththe patient died; cause not stated by this term47.2%11,487
  2. Toxicity to various agentspoisoning or toxic effect of one or more substances37.3%9,086
  3. Overdosea dose above the recommended amount22.4%5,446
  4. Drug dependencedependence on a medicine6.4%1,570
  5. Drug abusemisuse of a medicine6%1,459
  6. Accidental overdosean accidental overdose2.5%616
  7. Foetal exposure during pregnancythe unborn baby was exposed to the medicine1.5%367
  8. Maternal exposure during pregnancythe mother took the medicine during pregnancy1.4%329
  9. Drug prescribing errora prescribing mistake1.3%327
  10. Painpain, site not specified1.3%322
  11. Intentional product misusedeliberate use not as intended1.3%313
  12. Tremorshaking0.6%146
  13. Cryingcrying0.6%134
  14. Poor feeding infant0.5%130
  15. Opisthotonus0.5%127
  16. Hepatitis Chepatitis C infection0.5%126
  17. Live birth0.5%126
  18. Developmental delayslower development in a child0.5%120
  19. Drug ineffectivethe medicine did not work as expected0.4%90
  20. Off label useused for a purpose or in a way not on the label0.4%87
  21. Medication errora mistake in prescribing, dispensing or taking a medicine0.3%85
  22. Exposure during pregnancythe medicine was taken during pregnancy0.3%80
  23. Malaisegeneral feeling of being unwell0.2%58
  24. Drug withdrawal syndromesymptoms on stopping a medicine0.2%53
  25. Circumstance or information capable of leading to medication errora situation that could lead to a medication error0.2%44
  26. Nauseafeeling sick0.2%43
  27. Vomitingbeing sick0.2%42

Top 30 of 238 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 share of all reports in the database; 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

Death80.4%19,585
Life-threatening0%9
Hospitalisation (initial or prolonged)9.6%2,342
Disability0.1%14
Congenital anomaly3.7%891
Other serious20.1%4,886
Not serious3.2%776

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 20,646,523 reports. 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

Under 20.4%101
2 to 110%1
12 to 170%4
18 to 440.4%99
45 to 640.8%199
65 to 740.2%40
75 and over0.1%18
Age not given98.1%23,898

Patient sex

Female5%1,220
Male2.6%626
Not given92.4%22,514

Who reported

Physician1.3%327
Pharmacist0.5%124
Other health professional0.7%175
Lawyer80.6%19,638
Consumer or non-health professional16.7%4,069
Not given0.1%27

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 99.9% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Pain21,38587.8%
Back pain1090.4%
Breakthrough pain970.4%
Cancer pain830.3%
Migraine420.2%
Complex regional pain syndrome260.1%

The indication field is filled in by the reporter and is often blank; shares are of all 24,360 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Fentora reports
Actiq22,93994.2%
Percocet22,87593.9%
Opana22,83693.7%
Opana Er22,82193.7%
Duragesic22,79293.6%
Percodan22,59792.8%
OxyContin22,49692.3%
MS Contin22,39291.9%
Oxycodone hydrochloride22,38791.9%
Dilaudid22,36391.8%

Other products listed in reports where Fentora 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

MeasureFentoraAll reports
Reports as suspect product24,36020,646,523
Share of that pool—0.1%
Reports, latest 12 months11,332,454
Marked serious96.8%57.4%
Death recorded among outcomes, per 1,000 reports80491
Hospitalisation recorded, per 1,000 reports96213
Consumer-filed share16.7%45.8%
Top term, share of reportsDeath 47.2%4.1%

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."

Questions about Fentora reports

How many adverse event reports has FDA received for Fentora?

24,360 reports list Fentora as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1 of them arrived in the latest 12 months. Another 198 list it only as a concomitant medication.

What reactions are recorded in Fentora reports?

death (47.2%), toxicity to various agents (37.3%), overdose (22.4%), drug dependence (6.4%) and drug abuse (6%). 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 Fentora was responsible.

How serious are the reports?

96.8% are marked serious by the reporter. Among the outcomes recorded, 80.4% of reports include death and 9.6% 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?

lawyer (80.6%), consumer or non-health professional (16.7%) and physician (1.3%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Fentora rising?

1 reports in the 12 months to June 2026, down 75% from 4 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 Fentora 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 Fentora?

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 Fentora as a suspect or interacting product; reports listing it only as a concomitant medication (198) 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.