Quick answers
- What is Amifampridine phosphate used for?
- The FDA-approved label (Firdapse, Catalyst Pharmaceuticals, Inc., April 16, 2026) says: “FIRDAPSE ® is indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years of age and older. FIRDAPSE is a potassium channel blocker indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years of age and older.” This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
- Does Amifampridine phosphate have a boxed warning?
- No. None of the 1 FDA labels we found for this medicine has a boxed warning.
- Is there a shortage of Amifampridine phosphate?
- No current shortage is listed by the FDA for the products of this medicine (FDA data from October 30, 2026).
- Has Amifampridine phosphate been recalled?
- No recall linked to the products of this medicine appears in the FDA enforcement reports we use.
- Who makes Amifampridine phosphate?
- 1 company lists prescription products of Amifampridine phosphate in the FDA NDC Directory, including Catalyst Pharmaceuticals, Inc..
What Amifampridine phosphate is used for
Quoted from the “Indications and Usage” section of the FDA-approved label.
FIRDAPSE ® is indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years of age and older. FIRDAPSE is a potassium channel blocker indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years of age and older.
— FDA label: Firdapse, Catalyst Pharmaceuticals, Inc., effective April 16, 2026. Read the full label on DailyMed →
This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
Boxed warning
A boxed warning (“black box”) is the FDA’s strongest warning on a drug label, for serious or life-threatening risks.
The label quoted above has no boxed warning.
Forms and how it is given
| Dosage forms | Tablet |
|---|---|
| Route | Oral |
| Prescription products | 1 in the FDA NDC Directory |
| Brand names | Firdapse |
Companies that list this medicine
Labelers in the FDA NDC Directory: the company named on the package (maker or distributor), with the number of prescription products.
- Catalyst Pharmaceuticals, Inc.1 product
FDA approval history
- NDA: New Drug Application: how a new (usually brand-name) medicine is approved.
| Application | Sponsor | Approved | Later changes approved |
|---|---|---|---|
| NDA208078 FIRDAPSE | Catalyst Pharms | November 28, 2018 | 5, latest July 17, 2025 2025: Manufacturing (CMC) · 2024: Efficacy · 2023: Labeling |
Shortage status
The FDA drug shortage list does not show these products.
Recalls
No recall linked to these products (by their NDC code) appears in the FDA enforcement reports.
Official identifiers
| RxCUI (RxNorm) | 2106343, 2107518 |
|---|---|
| SPL set ID of the quoted label | f015fe60-3128-4a43-8c31-19fc6b5def3f |
| FDA labels (SPL) | 1 |
| FDA applications | NDA208078 |
| Active ingredients (FDA) | AMIFAMPRIDINE |
Sources
- FDA-approved label on DailyMed (National Library of Medicine) — Firdapse, Catalyst Pharmaceuticals, Inc., effective April 16, 2026; via openFDA, FDA data exported October 30, 2026, retrieved October 31, 2026
- NDC Directory (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
- Drugs@FDA (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
- Drug recall enforcement reports (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 27, 2026, retrieved October 31, 2026
- Drug shortages (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
openFDA data is provided by the FDA as is; it may be incomplete. Always rely on the label that comes with your medicine. FDA Enforcement Report search →