Reported Reactions

Drugs

Product name as reported

Mexiletine: adverse event reports filed with FDA

656 reports list it as a suspect or interacting product, 2004–2026.

656
reports as suspect product
0% of all reports · about 29 a year
42
reports, 12 months to June 2026
87 in the 12 months before
91.2%
marked serious by the reporter
57.4% across all reports
9.9%
record death among outcomes, as reported
65 reports · not verified by FDA

Between March 2004 and May 2026, 656 adverse event reports received by FDA list the product name "Mexiletine" as reporters wrote it as a suspect or interacting product. Reports that mention it only as a concomitant medication (786) are left out of every figure here.

In the 12 months to June 2026, 42 reports listed it, down 52% from 87 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 29 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.

The MedDRA terms listed most often are drug ineffective (40.2%), weight increased (12.8%) and off label use (11.3%). A report can list several reactions, so shares add to more than 100%; 181 different terms appear across these reports. Drug ineffective is recorded in 40.2% of these reports, against 6.3% of all reports in the database.

91.2% of the reports are marked serious by the reporter; 9.9% record death among the outcomes and 44.5% record hospitalisation, as reported. 54.9% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (29.9%). 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

01019Jul 2021: 5Aug 2021: 8Sep 2021: 10Oct 2021: 3Nov 2021: 11Dec 2021: 22022Jan 2022: 7Feb 2022: 10Mar 2022: 6Apr 2022: 4May 2022: 10Jun 2022: 4Jul 2022: 1Aug 2022: 4Sep 2022: 7Oct 2022: 8Nov 2022: 13Dec 2022: 32023Jan 2023: 5Feb 2023: 7Mar 2023: 1Apr 2023: 3May 2023: 15Jun 2023: 13Jul 2023: 6Aug 2023: 3Sep 2023: 10Oct 2023: 1Nov 2023: 11Dec 2023: 42024Jan 2024: 1Feb 2024: 3Mar 2024: 1Apr 2024: 2May 2024: 19Jun 2024: 8Jul 2024: 8Aug 2024: 1Sep 2024: 17Oct 2024: 10Nov 2024: 3Dec 2024: 112025Jan 2025: 2Feb 2025: 2Mar 2025: 6Apr 2025: 15May 2025: 6Jun 2025: 6Jul 2025: 7Aug 2025: 6Sep 2025: 10Oct 2025: 3Nov 2025: 1Dec 2025: 12026Jan 2026: 1Feb 2026: 5Mar 2026: 4Apr 2026: 0May 2026: 4Jun 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

0541082004: 620042005: 42010: 1120102012: 22013: 1620132014: 222015: 2620152016: 62017: 1720172018: 222019: 3320192020: 642021: 10820212022: 772023: 7920232024: 842025: 6520252026: 14

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Mexiletine reports recording the termall reports in the database

  1. Drug ineffectivethe medicine did not work as expected40.2%264
  2. Weight increasedweight gain12.8%84
  3. Off label useused for a purpose or in a way not on the label11.3%74
  4. Fatiguetiredness9.3%61
  5. Therapy non-responderthe treatment did not work8.8%58
  6. Insomniadifficulty sleeping8.4%55
  7. Contusiona bruise7.2%47
  8. Herpes zostershingles6.7%44
  9. Body tinea6.6%43
  10. Cellulitisa skin infection6.6%43
  11. Hyperlipidaemiaraised blood fats6.6%43
  12. Hypertensionhigh blood pressure6.6%43
  13. Infection susceptibility increased6.6%43
  14. Oral herpesa cold sore6.6%43
  15. Purpura6.6%43
  16. Cataractclouding of the eye lens6.4%42
  17. Inhibitory drug interaction6.4%42
  18. Impaired work abilityreduced ability to work5.8%38
  19. Immune thrombocytopenia5.6%37
  20. Treatment failurethe treatment did not work5%33
  21. Ventricular tachycardiaa fast rhythm from the lower heart chambers4.3%28
  22. Product use in unapproved indicationused for a purpose not on the label3.7%24
  23. Drug interactionan interaction between medicines3.5%23
  24. Electrocardiogram QT prolongeda QT prolongation on the ECG3.4%22

Top 30 of 181 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

Death9.9%65
Life-threatening13%85
Hospitalisation (initial or prolonged)44.5%292
Disability0.5%3
Congenital anomaly0%0
Other serious60.5%397
Not serious8.8%58

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 24%26
2 to 112.3%15
12 to 172.1%14
18 to 4417.5%115
45 to 6429.9%196
65 to 7415.7%103
75 and over7.8%51
Age not given20.7%136

Patient sex

Female43.1%283
Male46.6%306
Not given10.2%67

Who reported

Physician29.6%194
Pharmacist3.2%21
Other health professional54.9%360
Lawyer0%0
Consumer or non-health professional9.8%64
Not given2.6%17

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 57% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Ventricular tachycardia16525.2%
Complex regional pain syndrome8813.4%
Arrhythmia314.7%
Ventricular fibrillation172.6%
Long QT syndrome152.3%
Ventricular arrhythmia121.8%

The indication field is filled in by the reporter and is often blank; shares are of all 656 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Mexiletine reports
Amiodarone21232.3%
Lidocaine17626.8%
Pregabalin9714.8%
Ketamine9214%
Metoprolol8913.6%
Clonidine8613.1%
Gabapentin8012.2%
Amitriptyline7611.6%
Prednisone7311.1%
Spironolactone6710.2%

Other products listed in reports where Mexiletine 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

MeasureMexiletineAll reports
Reports as suspect product65620,646,523
Share of that pool—0%
Reports, latest 12 months421,332,454
Marked serious91.2%57.4%
Death recorded among outcomes, per 1,000 reports9991
Hospitalisation recorded, per 1,000 reports445213
Consumer-filed share9.8%45.8%
Top term, share of reportsDrug ineffective 40.2%6.3%

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 Mexiletine reports

How many adverse event reports has FDA received for Mexiletine?

656 reports list Mexiletine as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 42 of them arrived in the latest 12 months. Another 786 list it only as a concomitant medication.

What reactions are recorded in Mexiletine reports?

drug ineffective (40.2%), weight increased (12.8%), off label use (11.3%), fatigue (9.3%) and therapy non-responder (8.8%). 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 Mexiletine was responsible.

How serious are the reports?

91.2% are marked serious by the reporter. Among the outcomes recorded, 9.9% of reports include death and 44.5% 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 (54.9%), physician (29.6%) and consumer or non-health professional (9.8%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Mexiletine rising?

42 reports in the 12 months to June 2026, down 52% from 87 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 Mexiletine 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 Mexiletine?

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 Mexiletine as a suspect or interacting product; reports listing it only as a concomitant medication (786) 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.