Reported Reactions

Drugs › Carbonic anhydrase inhibitor

Brand name · Dichlorphenamide

Keveyis: adverse event reports filed with FDA

1,559 reports list it as a suspect or interacting product, 2015–2026. Class: Carbonic anhydrase inhibitor.

1,559
reports as suspect product
0% of all reports · about 146 a year
41
reports, 12 months to June 2026
24 in the 12 months before
27.2%
marked serious by the reporter
40.1% across the class
0.8%
record death among outcomes, as reported
13 reports · not verified by FDA

Between November 2015 and June 2026, 1,559 adverse event reports received by FDA list the brand name Keveyis (dichlorphenamide) as a suspect or interacting product. Reports that mention it only as a concomitant medication (8) are left out of every figure here.

In the 12 months to June 2026, 41 reports listed it, up 71% from 24 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 146 reports a year and 0% of the 20,646,523 reports in the database, and 8% of the reports for the carbonic anhydrase inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded paraesthesia (18.5%), fatigue (13.9%) and disease recurrence (11%). A report can list several reactions, so shares add to more than 100%; 338 different terms appear across these reports. Paraesthesia is recorded in 18.5% of these reports, a larger share than in the median carbonic anhydrase inhibitor drug (0.1%).

27.2% of the reports are marked serious by the reporter (40.1% across the class); 0.8% record death among the outcomes and 15.3% record hospitalisation, as reported. 49.9% of the reports came from consumers, and the largest patient age group is 18 to 44 (20.2%). 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

02141Jul 2021: 25Aug 2021: 36Sep 2021: 33Oct 2021: 19Nov 2021: 41Dec 2021: 322022Jan 2022: 5Feb 2022: 1Mar 2022: 3Apr 2022: 4May 2022: 0Jun 2022: 3Jul 2022: 3Aug 2022: 4Sep 2022: 2Oct 2022: 1Nov 2022: 2Dec 2022: 32023Jan 2023: 2Feb 2023: 1Mar 2023: 1Apr 2023: 4May 2023: 3Jun 2023: 3Jul 2023: 1Aug 2023: 4Sep 2023: 2Oct 2023: 2Nov 2023: 2Dec 2023: 42024Jan 2024: 2Feb 2024: 1Mar 2024: 5Apr 2024: 5May 2024: 3Jun 2024: 0Jul 2024: 2Aug 2024: 3Sep 2024: 2Oct 2024: 0Nov 2024: 2Dec 2024: 02025Jan 2025: 4Feb 2025: 1Mar 2025: 3Apr 2025: 1May 2025: 4Jun 2025: 2Jul 2025: 3Aug 2025: 3Sep 2025: 14Oct 2025: 3Nov 2025: 4Dec 2025: 02026Jan 2026: 0Feb 2026: 1Mar 2026: 5Apr 2026: 2May 2026: 3Jun 2026: 3

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

01743482015: 920152016: 372017: 15720172018: 3122019: 26020192020: 2952021: 34820212022: 312023: 2920232024: 252025: 4220252026: 14

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Keveyis reports recording the termmedian drug in carbonic anhydrase inhibitor

  1. Paraesthesiatingling or pins and needles18.5%289
  2. Fatiguetiredness13.9%217
  3. Disease recurrencethe disease came back11%172
  4. Feeling abnormalfeeling odd or not right10.1%157
  5. Muscular weaknessmuscle weakness10.1%157
  6. Wrong technique in product usage processthe product was used in the wrong way9.6%149
  7. Astheniaweakness or lack of energy8.3%129
  8. Confusional stateconfusion7.8%121
  9. Dizzinesslight-headedness or unsteadiness7%109
  10. Nauseafeeling sick7%109
  11. Headachehead pain5.9%92
  12. Dysgeusiaaltered taste5.8%91
  13. Condition aggravatedthe condition being treated got worse5.4%84
  14. Diarrhoealoose or frequent stools5.3%83
  15. Malaisegeneral feeling of being unwell5.3%82
  16. Hypoaesthesianumbness5.1%79
  17. Dyspnoeashortness of breath4.9%76
  18. Memory impairmentmemory problems4.5%70
  19. Muscle spasmsmuscle cramps4.5%70
  20. Painpain, site not specified4.5%70
  21. Falla fall4.4%68
  22. Insomniadifficulty sleeping3.8%59
  23. Paralysis3.5%54
  24. Weight decreasedweight loss3.4%53
  25. Myalgiamuscle pain3.3%52
  26. Decreased appetitereduced appetite3.2%50
  27. Product dose omission issuea dose was missed3%47
  28. Abdominal discomfortstomach discomfort2.7%42
  29. Hypokalaemialow blood potassium2.7%42

Top 30 of 338 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 12 drugs in the carbonic anhydrase inhibitor 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

Death0.8%13
Life-threatening0.4%7
Hospitalisation (initial or prolonged)15.3%238
Disability0.1%2
Congenital anomaly0.1%1
Other serious15.2%237
Not serious72.8%1,135

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 19,384 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

Under 20%0
2 to 110.2%3
12 to 173.1%48
18 to 4420.2%315
45 to 6419.8%308
65 to 745.5%85
75 and over1.8%28
Age not given49.5%772

Patient sex

Female50.2%782
Male43.3%675
Not given6.5%102

Who reported

Physician14.9%232
Pharmacist30.8%480
Other health professional3.9%61
Lawyer0%0
Consumer or non-health professional49.9%778
Not given0.5%8

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 100% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Familial periodic paralysis74447.7%
Paralysis1237.9%
Myotonia191.2%
Myotonia congenita110.7%
Long QT syndrome90.6%
Muscle disorder20.1%

The indication field is filled in by the reporter and is often blank; shares are of all 1,559 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Keveyis reports
Potassium543.5%
Spironolactone181.2%
Potassium chloride171.1%
Acetazolamide120.8%
Metformin80.5%
Gabapentin70.4%
Midodrine70.4%
Atorvastatin60.4%
Magnesium60.4%
Metoprolol60.4%

Other products listed in reports where Keveyis 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

MeasureKeveyisCarbonic anhydrase inhibitorAll reports
Reports as suspect product1,55919,38420,646,523
Share of that pool—8%0%
Reports, latest 12 months41—1,332,454
Marked serious27.2%40.1%57.4%
Death recorded among outcomes, per 1,000 reports84991
Hospitalisation recorded, per 1,000 reports153115213
Consumer-filed share49.9%52.8%45.8%
Top term, share of reportsParaesthesia 18.5%median 0.1%0.8%

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 carbonic anhydrase inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Azoptbrand3,6564037.5%
Simbrinzabrand2,9536433.9%
Acetazolamidegeneric2,56725987.3%
Dorzolamidegeneric2,0737518.2%
Cosopt Pfbrand1,8801219.7%
Cosoptbrand1,3473066.9%
Brinzolamidegeneric8866673%
Dorzolamide hydrochloridegeneric6927232.2%
Dorzolamide hclgeneric68802.8%
Dorzolamide and Timololbrand562411.4%
Dorzolamide hydrochloride timolol maleategeneric52110325%

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 Keveyis reports

How many adverse event reports has FDA received for Keveyis?

1,559 reports list Keveyis as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 41 of them arrived in the latest 12 months. Another 8 list it only as a concomitant medication.

What reactions are recorded in Keveyis reports?

paraesthesia (18.5%), fatigue (13.9%), disease recurrence (11%), feeling abnormal (10.1%) and muscular weakness (10.1%). 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 Keveyis was responsible.

How serious are the reports?

27.2% are marked serious by the reporter. Among the outcomes recorded, 0.8% of reports include death and 15.3% 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 (49.9%), pharmacist (30.8%) and physician (14.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Keveyis rising?

41 reports in the 12 months to June 2026, up 71% from 24 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 Keveyis 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 Keveyis?

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 Keveyis as a suspect or interacting product; reports listing it only as a concomitant medication (8) 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.