Drugs › Potassium channel blocker
Generic name
Dalfampridine: adverse event reports filed with FDA
5,760 reports list it as a suspect or interacting product, 2011–2026. Class: Potassium channel blocker. Also reported as Dalfampridine 10mg Er Tab, Dalfampridine Er, Dalfampridine 10mg Er.
- 5,760
- reports as suspect product
- 0% of all reports · about 376 a year
- 301
- reports, 12 months to June 2026
- 333 in the 12 months before
- 51.9%
- marked serious by the reporter
- 26.9% across the class
- 7.4%
- record death among outcomes, as reported
- 429 reports · not verified by FDA
Between March 2011 and June 2026, 5,760 adverse event reports received by FDA list dalfampridine, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (2,597) are left out of every figure here.
In the 12 months to June 2026, 301 reports listed it, down 10% from 333 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 376 reports a year and 0% of the 20,646,523 reports in the database, and 8.9% of the reports for the potassium channel blocker class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded fall (13.4%), drug ineffective (12.7%) and gait disturbance (11.9%). A report can list several reactions, so shares add to more than 100%; 829 different terms appear across these reports. Fall is recorded in 13.4% of these reports, a larger share than in the median potassium channel blocker drug (9.7%).
51.9% of the reports are marked serious by the reporter (26.9% across the class); 7.4% record death among the outcomes and 28.8% record hospitalisation, as reported. 53.6% of the reports came from consumers, and the largest patient age group is 45 to 64 (28.6%). 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
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
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Dalfampridine reports recording the termmedian drug in potassium channel blocker
- Falla fall13.4%774
- Drug ineffectivethe medicine did not work as expected12.7%731
- Gait disturbancedifficulty walking11.9%685
- Therapy cessation7.5%434
- Fatiguetiredness7%401
- Balance disorderproblems with balance6.6%378
- Condition aggravatedthe condition being treated got worse6%348
- Deaththe patient died; cause not stated by this term5.9%342
- Multiple sclerosis relapsea flare of multiple sclerosis5.7%330
- Multiple sclerosis5.3%308
- Dizzinesslight-headedness or unsteadiness4.8%274
- Mobility decreasedreduced ability to move about4.6%266
- Astheniaweakness or lack of energy4.1%235
- Muscular weaknessmuscle weakness4%230
- Headachehead pain3.8%221
- Seizurea fit or convulsion3.3%190
- Hypoaesthesianumbness3.1%180
- Urinary tract infectionbladder or urinary infection3%174
- Nauseafeeling sick3%172
- Insomniadifficulty sleeping2.9%167
- Painpain, site not specified2.8%160
- Pain in extremitypain in an arm or leg2.7%154
- Therapy interrupted2.5%142
- Off label useused for a purpose or in a way not on the label2.4%138
- Product dose omission issuea dose was missed2.3%135
- Product substitution issuea problem after switching products2.3%132
- Covid-19COVID-19 infection2.2%127
- Flushingsudden reddening or warmth of the skin2.2%126
- Diarrhoealoose or frequent stools2.1%119
- Muscle spasmsmuscle cramps2%114
Top 30 of 829 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 potassium channel blocker 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
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 64,845 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
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 73.8% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Multiple sclerosis | 2,443 | 42.4% |
| Gait disturbance | 577 | 10% |
| Relapsing-remitting multiple sclerosis | 54 | 0.9% |
| Secondary progressive multiple sclerosis | 41 | 0.7% |
| Cognitive disorder | 23 | 0.4% |
| Primary progressive multiple sclerosis | 23 | 0.4% |
The indication field is filled in by the reporter and is often blank; shares are of all 5,760 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Dalfampridine reports |
|---|---|---|
| Ampyra | 1,356 | 23.5% |
| Baclofen | 755 | 13.1% |
| Tecfidera | 752 | 13.1% |
| Gabapentin | 437 | 7.6% |
| Ergocalciferol | 424 | 7.4% |
| Tysabri | 307 | 5.3% |
| Aspirin | 263 | 4.6% |
| Vitamin d | 213 | 3.7% |
| Ocrevus | 191 | 3.3% |
| Vumerity | 184 | 3.2% |
Other products listed in reports where Dalfampridine 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
| Measure | Dalfampridine | Potassium channel blocker | All reports |
|---|---|---|---|
| Reports as suspect product | 5,760 | 64,845 | 20,646,523 |
| Share of that pool | — | 8.9% | 0% |
| Reports, latest 12 months | 301 | — | 1,332,454 |
| Marked serious | 51.9% | 26.9% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 74 | 27 | 91 |
| Hospitalisation recorded, per 1,000 reports | 288 | 133 | 213 |
| Consumer-filed share | 53.6% | 75.1% | 45.8% |
| Top term, share of reports | Fall 13.4% | median 9.7% | 1.6% |
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 potassium channel blocker class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Ampyra | brand | 56,261 | 295 | 23% |
| Firdapse | brand | 2,824 | 738 | 51.9% |
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 Dalfampridine reports
How many adverse event reports has FDA received for Dalfampridine?
5,760 reports list Dalfampridine as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 301 of them arrived in the latest 12 months. Another 2,597 list it only as a concomitant medication.
What reactions are recorded in Dalfampridine reports?
fall (13.4%), drug ineffective (12.7%), gait disturbance (11.9%), therapy cessation (7.5%) and fatigue (7%). 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 Dalfampridine was responsible.
How serious are the reports?
51.9% are marked serious by the reporter. Among the outcomes recorded, 7.4% of reports include death and 28.8% 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 (53.6%), other health professional (20.8%) and physician (9.3%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Dalfampridine rising?
301 reports in the 12 months to June 2026, down 10% from 333 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 Dalfampridine 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 Dalfampridine?
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 Dalfampridine as a suspect or interacting product; reports listing it only as a concomitant medication (2,597) 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.