Reported Reactions

Drugs

Brand name · Glycerol phenylbutyrate

Ravicti: adverse event reports filed with FDA

1,304 reports list it as a suspect or interacting product, 2013–2026.

1,304
reports as suspect product
0% of all reports · about 100 a year
59
reports, 12 months to June 2026
132 in the 12 months before
59%
marked serious by the reporter
57.4% across all reports
4.8%
record death among outcomes, as reported
63 reports · not verified by FDA

Between July 2013 and June 2026, 1,304 adverse event reports received by FDA list the brand name Ravicti (glycerol phenylbutyrate) as a suspect or interacting product. Reports that mention it only as a concomitant medication (24) are left out of every figure here.

In the 12 months to June 2026, 59 reports listed it, down 55% from 132 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 100 reports a year and 0% 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.

Reporters most often recorded ammonia increased (14.4%), vomiting (12.3%) and hyperammonaemia (11.5%). A report can list several reactions, so shares add to more than 100%; 206 different terms appear across these reports. Ammonia increased is recorded in 14.4% of these reports, against 0% of all reports in the database.

59% of the reports are marked serious by the reporter; 4.8% record death among the outcomes and 43.7% record hospitalisation, as reported. 61.4% of the reports came from consumers, and the largest patient age group is 18 to 44 (23.5%). 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

02448Jul 2021: 1Aug 2021: 1Sep 2021: 0Oct 2021: 1Nov 2021: 2Dec 2021: 32022Jan 2022: 3Feb 2022: 4Mar 2022: 1Apr 2022: 2May 2022: 7Jun 2022: 1Jul 2022: 2Aug 2022: 3Sep 2022: 3Oct 2022: 2Nov 2022: 1Dec 2022: 32023Jan 2023: 2Feb 2023: 2Mar 2023: 48Apr 2023: 2May 2023: 5Jun 2023: 3Jul 2023: 2Aug 2023: 3Sep 2023: 6Oct 2023: 2Nov 2023: 8Dec 2023: 102024Jan 2024: 4Feb 2024: 11Mar 2024: 18Apr 2024: 4May 2024: 15Jun 2024: 23Jul 2024: 25Aug 2024: 14Sep 2024: 32Oct 2024: 10Nov 2024: 12Dec 2024: 172025Jan 2025: 14Feb 2025: 4Mar 2025: 2Apr 2025: 0May 2025: 1Jun 2025: 1Jul 2025: 3Aug 2025: 3Sep 2025: 5Oct 2025: 1Nov 2025: 1Dec 2025: 22026Jan 2026: 2Feb 2026: 0Mar 2026: 4Apr 2026: 19May 2026: 7Jun 2026: 12

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

01352692013: 920132014: 192015: 26920152016: 2572017: 10220172018: 802019: 9220192020: 572021: 2820212022: 322023: 9320232024: 1852025: 3720252026: 44

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Ravicti reports recording the termall reports in the database

  1. Ammonia increased14.4%188
  2. Vomitingbeing sick12.3%160
  3. Hyperammonaemia11.5%150
  4. Decreased appetitereduced appetite7.8%102
  5. Nauseafeeling sick5%65
  6. Headachehead pain4.8%63
  7. Diarrhoealoose or frequent stools4.2%55
  8. Hyperammonaemic crisis4.1%54
  9. Off label useused for a purpose or in a way not on the label4.1%54
  10. Fatiguetiredness3.6%47
  11. Somnolencedrowsiness3.5%46
  12. Malaisegeneral feeling of being unwell3.4%44
  13. Seizurea fit or convulsion3.2%42
  14. Weight decreasedweight loss3.1%41
  15. Lethargysluggishness2.8%36
  16. Dizzinesslight-headedness or unsteadiness2.3%30
  17. Hospitalisationadmission to hospital2.3%30
  18. Abdominal pain upperupper stomach pain2.2%29
  19. Influenzaflu2.1%28
  20. Liver transplant2.1%28
  21. Amino acid level increased2.1%27
  22. Drug dose omissiona dose was missed2.1%27
  23. Pyrexiafever2.1%27
  24. Abdominal discomfortstomach discomfort2%26
  25. Nasopharyngitisa cold2%26
  26. Deaththe patient died; cause not stated by this term1.8%24
  27. Irritabilityirritability1.6%21
  28. Coughcough1.5%19

Top 30 of 206 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

Death4.8%63
Life-threatening1.5%19
Hospitalisation (initial or prolonged)43.7%570
Disability0.1%1
Congenital anomaly0%0
Other serious18.6%242
Not serious41%535

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 26.8%89
2 to 1123.2%303
12 to 1710.3%134
18 to 4423.5%307
45 to 645.7%74
65 to 741.7%22
75 and over0.7%9
Age not given28.1%366

Patient sex

Female48.8%636
Male34.7%452
Not given16.6%216

Who reported

Physician15.1%197
Pharmacist2.8%37
Other health professional19.4%253
Lawyer0%0
Consumer or non-health professional61.4%801
Not given1.2%16

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 92% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Ornithine transcarbamoylase deficiency35126.9%
Urea cycle enzyme deficiency27521.1%
Urea cycle disorder20916%
Argininosuccinate synthetase deficiency826.3%
Argininosuccinate lyase deficiency796.1%
Arginase deficiency493.8%

The indication field is filled in by the reporter and is often blank; shares are of all 1,304 reports.

In context

MeasureRavictiAll reports
Reports as suspect product1,30420,646,523
Share of that pool—0%
Reports, latest 12 months591,332,454
Marked serious59%57.4%
Death recorded among outcomes, per 1,000 reports4891
Hospitalisation recorded, per 1,000 reports437213
Consumer-filed share61.4%45.8%
Top term, share of reportsAmmonia increased 14.4%0%

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 Ravicti reports

How many adverse event reports has FDA received for Ravicti?

1,304 reports list Ravicti as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 59 of them arrived in the latest 12 months. Another 24 list it only as a concomitant medication.

What reactions are recorded in Ravicti reports?

ammonia increased (14.4%), vomiting (12.3%), hyperammonaemia (11.5%), decreased appetite (7.8%) and nausea (5%). 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 Ravicti was responsible.

How serious are the reports?

59% are marked serious by the reporter. Among the outcomes recorded, 4.8% of reports include death and 43.7% 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?

consumer or non-health professional (61.4%), other health professional (19.4%) and physician (15.1%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Ravicti rising?

59 reports in the 12 months to June 2026, down 55% from 132 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 Ravicti 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 Ravicti?

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 Ravicti as a suspect or interacting product; reports listing it only as a concomitant medication (24) 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.