Reported Reactions

Drugs

Product name as reported

Rebetol: adverse event reports filed with FDA

12,779 reports list it as a suspect or interacting product, 2004–2023.

12,779
reports as suspect product
0.1% of all reports · about 568 a year
0
reports, 12 months to June 2026
0 in the 12 months before
74.4%
marked serious by the reporter
57.4% across all reports
5.1%
record death among outcomes, as reported
653 reports · not verified by FDA

12,779 adverse event reports received by FDA list the product name "Rebetol" as reporters wrote it as a suspect or interacting product, from January 2004 to March 2023. A further 1,041 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, 0 reports listed it, and none 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 568 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 MedDRA terms listed most often are anaemia (16.3%), fatigue (9.9%) and nausea (8.8%). A report can list several reactions, so shares add to more than 100%; 1,483 different terms appear across these reports. Anaemia is recorded in 16.3% of these reports, against 0.9% of all reports in the database.

74.4% of the reports are marked serious by the reporter; 5.1% record death among the outcomes and 35.7% record hospitalisation, as reported. 35.8% of the reports came from physicians, and the largest patient age group is 45 to 64 (44.6%). 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

036Jul 2021: 1Aug 2021: 4Sep 2021: 2Oct 2021: 0Nov 2021: 0Dec 2021: 22022Jan 2022: 0Feb 2022: 1Mar 2022: 3Apr 2022: 2May 2022: 3Jun 2022: 1Jul 2022: 1Aug 2022: 6Sep 2022: 1Oct 2022: 1Nov 2022: 0Dec 2022: 12023Jan 2023: 3Feb 2023: 0Mar 2023: 1Apr 2023: 0May 2023: 0Jun 2023: 0Jul 2023: 0Aug 2023: 0Sep 2023: 0Oct 2023: 0Nov 2023: 0Dec 2023: 02024Jan 2024: 0Feb 2024: 0Mar 2024: 0Apr 2024: 0May 2024: 0Jun 2024: 0Jul 2024: 0Aug 2024: 0Sep 2024: 0Oct 2024: 0Nov 2024: 0Dec 2024: 02025Jan 2025: 0Feb 2025: 0Mar 2025: 0Apr 2025: 0May 2025: 0Jun 2025: 0Jul 2025: 0Aug 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

01,8373,6732004: 52620042005: 5722006: 47520062007: 4262008: 41020082009: 2472010: 24820102011: 2162012: 3,67320122013: 2,4982014: 1,17620142015: 7802016: 72920162017: 4002018: 16520182019: 962020: 9220202021: 262022: 2020222023: 4

Reactions recorded in the reports

share of Rebetol reports recording the termall reports in the database

  1. Anaemialow red blood cells16.3%2,081
  2. Fatiguetiredness9.9%1,263
  3. Nauseafeeling sick8.8%1,120
  4. Haemoglobin decreasedlow haemoglobin6.7%858
  5. Rashskin rash6.6%846
  6. Decreased appetitereduced appetite6.5%829
  7. White blood cell count decreasedlow white cell count6.4%816
  8. Pyrexiafever6.1%778
  9. Headachehead pain6.1%774
  10. Astheniaweakness or lack of energy5.6%718
  11. Vomitingbeing sick5.5%701
  12. Malaisegeneral feeling of being unwell5.2%659
  13. Weight decreasedweight loss5.1%649
  14. Depressionlow mood4.9%628
  15. Platelet count decreasedlow platelet count4.8%613
  16. Drug ineffectivethe medicine did not work as expected4.4%558
  17. Insomniadifficulty sleeping4%516
  18. Dyspnoeashortness of breath3.9%500
  19. Diarrhoealoose or frequent stools3.9%499
  20. Dizzinesslight-headedness or unsteadiness3.8%483
  21. Influenza like illnessflu-like symptoms3.7%479
  22. Pruritusitching3.7%468
  23. Dysgeusiaaltered taste3.4%433
  24. Painpain, site not specified3.3%420
  25. Dehydrationdehydration2.8%357
  26. Chillschills or shivering2.7%342
  27. Alopeciahair loss2.4%301
  28. Neutropenialow neutrophils, a type of white blood cell2.4%301
  29. Thrombocytopenialow platelets2.3%294

Top 30 of 1,483 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

Death5.1%653
Life-threatening4.2%541
Hospitalisation (initial or prolonged)35.7%4,562
Disability2.9%369
Congenital anomaly0.3%40
Other serious49%6,262
Not serious25.6%3,271

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 20.3%34
2 to 110.1%15
12 to 170.1%18
18 to 4410.7%1,363
45 to 6444.6%5,697
65 to 7414.2%1,814
75 and over2.3%294
Age not given27.7%3,544

Patient sex

Female40.4%5,162
Male51.2%6,540
Not given8.4%1,077

Who reported

Physician35.8%4,572
Pharmacist4%511
Other health professional25.8%3,298
Lawyer0%3
Consumer or non-health professional32.4%4,146
Not given1.9%249

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 41.3% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Hepatitis c6,76252.9%
Chronic hepatitis c3,51527.5%
Hepatic cirrhosis1411.1%
Hepatitis720.6%
Chronic hepatitis360.3%
Hepatitis c virus test positive360.3%

The indication field is filled in by the reporter and is often blank; shares are of all 12,779 reports.

In context

MeasureRebetolAll reports
Reports as suspect product12,77920,646,523
Share of that pool—0.1%
Reports, latest 12 months01,332,454
Marked serious74.4%57.4%
Death recorded among outcomes, per 1,000 reports5191
Hospitalisation recorded, per 1,000 reports357213
Consumer-filed share32.4%45.8%
Top term, share of reportsAnaemia 16.3%0.9%

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 Rebetol reports

How many adverse event reports has FDA received for Rebetol?

12,779 reports list Rebetol as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 0 of them arrived in the latest 12 months. Another 1,041 list it only as a concomitant medication.

What reactions are recorded in Rebetol reports?

anaemia (16.3%), fatigue (9.9%), nausea (8.8%), haemoglobin decreased (6.7%) and rash (6.6%). 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 Rebetol was responsible.

How serious are the reports?

74.4% are marked serious by the reporter. Among the outcomes recorded, 5.1% of reports include death and 35.7% 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?

physician (35.8%), consumer or non-health professional (32.4%) and other health professional (25.8%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Rebetol rising?

0 reports in the 12 months to June 2026, and none 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 Rebetol 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 Rebetol?

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 Rebetol as a suspect or interacting product; reports listing it only as a concomitant medication (1,041) 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.