Reported Reactions

Drugs › Influenza A M2 protein inhibitor

Generic name

Amantadine: adverse event reports filed with FDA

2,205 reports list it as a suspect or interacting product, 2004–2026. Class: Influenza A M2 protein inhibitor. Also reported as Amantadine 100mg, Amantadine /00055902/.

2,205
reports as suspect product
0% of all reports · about 100 a year
200
reports, 12 months to June 2026
133 in the 12 months before
82%
marked serious by the reporter
67.8% across the class
9.3%
record death among outcomes, as reported
204 reports · not verified by FDA

Between June 2004 and June 2026, 2,205 adverse event reports received by FDA list amantadine, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (10,769) are left out of every figure here.

In the 12 months to June 2026, 200 reports listed it, up 50% from 133 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, and 48.2% of the reports for the influenza A M2 protein inhibitor class. 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 (12.2%), dyskinesia (10.6%) and hallucination (10.6%). A report can list several reactions, so shares add to more than 100%; 606 different terms appear across these reports. Drug ineffective is recorded in 12.2% of these reports, a larger share than in the median influenza A M2 protein inhibitor drug (7.3%).

82% of the reports are marked serious by the reporter (67.8% across the class); 9.3% record death among the outcomes and 40% record hospitalisation, as reported. 39.3% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (22.8%). 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

01938Jul 2021: 19Aug 2021: 17Sep 2021: 14Oct 2021: 13Nov 2021: 8Dec 2021: 72022Jan 2022: 10Feb 2022: 17Mar 2022: 20Apr 2022: 19May 2022: 10Jun 2022: 11Jul 2022: 4Aug 2022: 10Sep 2022: 15Oct 2022: 7Nov 2022: 19Dec 2022: 162023Jan 2023: 6Feb 2023: 6Mar 2023: 15Apr 2023: 20May 2023: 10Jun 2023: 17Jul 2023: 26Aug 2023: 20Sep 2023: 14Oct 2023: 16Nov 2023: 35Dec 2023: 152024Jan 2024: 10Feb 2024: 9Mar 2024: 17Apr 2024: 15May 2024: 30Jun 2024: 19Jul 2024: 22Aug 2024: 13Sep 2024: 7Oct 2024: 15Nov 2024: 12Dec 2024: 112025Jan 2025: 9Feb 2025: 3Mar 2025: 8Apr 2025: 9May 2025: 11Jun 2025: 13Jul 2025: 28Aug 2025: 6Sep 2025: 7Oct 2025: 4Nov 2025: 21Dec 2025: 272026Jan 2026: 14Feb 2026: 11Mar 2026: 25Apr 2026: 38May 2026: 13Jun 2026: 6

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

01292572004: 620042005: 92008: 12009: 1020092010: 152011: 52012: 3220122013: 912014: 862015: 9420152016: 982017: 882018: 25720182019: 1902020: 2542021: 17820212022: 1582023: 2002024: 18020242025: 1462026: 107

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Amantadine reports recording the termmedian drug in influenza a m2 protein inhibitor

  1. Drug ineffectivethe medicine did not work as expected12.2%270
  2. Dyskinesiainvoluntary movements10.6%233
  3. Hallucinationseeing or hearing things that are not there10.6%233
  4. Off label useused for a purpose or in a way not on the label9.3%204
  5. Falla fall8.3%182
  6. Tremorshaking6.6%146
  7. Drug interactionan interaction between medicines6.5%144
  8. Fatiguetiredness5.5%122
  9. Confusional stateconfusion5.4%119
  10. Gait disturbancedifficulty walking5.1%113
  11. Dizzinesslight-headedness or unsteadiness5%110
  12. Dystoniainvoluntary muscle contractions4.6%102
  13. Toxicity to various agentspoisoning or toxic effect of one or more substances4.6%101
  14. Somnolencedrowsiness4.5%100
  15. Psychotic disordera loss of contact with reality4.2%92
  16. Condition aggravatedthe condition being treated got worse4.1%91
  17. Serotonin syndrometoo much serotonin activity, with agitation, fever and tremor3.9%85
  18. Balance disorderproblems with balance3.8%84
  19. Insomniadifficulty sleeping3.7%82
  20. Anxietyanxiety3.6%80
  21. Neuroleptic malignant syndromea rare severe reaction with fever and rigidity3.6%80
  22. Product use in unapproved indicationused for a purpose not on the label3.4%75
  23. Astheniaweakness or lack of energy3.3%73
  24. Agitationrestlessness3.2%71
  25. Constipationconstipation3.2%70
  26. Parkinson's disease psychosis2.9%63

Top 30 of 606 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 3 drugs in the influenza a m2 protein 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

Death9.3%204
Life-threatening5.9%129
Hospitalisation (initial or prolonged)40%883
Disability2.3%51
Congenital anomaly0.3%7
Other serious57.3%1,263
Not serious18%396

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 4,578 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 20.3%6
2 to 110.9%20
12 to 172.2%49
18 to 4411.7%258
45 to 6422.8%503
65 to 7421.7%479
75 and over12.8%283
Age not given27.5%607

Patient sex

Female46%1,014
Male42.2%931
Not given11.8%260

Who reported

Physician26.6%587
Pharmacist3.6%80
Other health professional39.3%867
Lawyer0%0
Consumer or non-health professional27.5%607
Not given2.9%64

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 57.5% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Parkinson's disease47621.6%
Dyskinesia1195.4%
Catatonia482.2%
Fatigue351.6%
Parkinsonism341.5%
Multiple sclerosis271.2%

The indication field is filled in by the reporter and is often blank; shares are of all 2,205 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Amantadine reports
Pramipexole24511.1%
Carbidopa levodopa24110.9%
Ropinirole2049.3%
Levodopa2019.1%
Clonazepam1868.4%
Quetiapine1757.9%
Entacapone1577.1%
Sinemet1567.1%
Gabapentin1466.6%
Carbidopa and levodopa1376.2%

Other products listed in reports where Amantadine 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

MeasureAmantadineInfluenza A M2 protein inhibitorAll reports
Reports as suspect product2,2054,57820,646,523
Share of that pool—48.2%0%
Reports, latest 12 months200—1,332,454
Marked serious82%67.8%57.4%
Death recorded among outcomes, per 1,000 reports939591
Hospitalisation recorded, per 1,000 reports400340213
Consumer-filed share27.5%40.3%45.8%
Top term, share of reportsDrug ineffective 12.2%median 7.3%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."

Other drugs in the influenza a m2 protein inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Gocovribrand1,6337544%
Amantadine hydrochloridegeneric7408178.1%

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 Amantadine reports

How many adverse event reports has FDA received for Amantadine?

2,205 reports list Amantadine as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 200 of them arrived in the latest 12 months. Another 10,769 list it only as a concomitant medication.

What reactions are recorded in Amantadine reports?

drug ineffective (12.2%), dyskinesia (10.6%), hallucination (10.6%), off label use (9.3%) and fall (8.3%). 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 Amantadine was responsible.

How serious are the reports?

82% are marked serious by the reporter. Among the outcomes recorded, 9.3% of reports include death and 40% 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 (39.3%), consumer or non-health professional (27.5%) and physician (26.6%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Amantadine rising?

200 reports in the 12 months to June 2026, up 50% from 133 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 Amantadine 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 Amantadine?

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 Amantadine as a suspect or interacting product; reports listing it only as a concomitant medication (10,769) 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.