Official HCP Site | FIRDAPSE® (amifampridine)

The maximum total daily dose has increased! Learn more now!

man wearing black cowboy hat reclining in chair

man wearing black cowboy hat reclining in chair

The maximum total daily dose has increased! Learn more now!

The recommended first-line therapy for patients living with Lambert-Eaton myasthenic syndrome (LEMS)¹

Clinically proven to maintain muscle strength and mobility^2-4

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What is LEMS?

LEMS is a rare, immune-mediated neuromuscular disorder that results in progressive, debilitating muscle weakness and fatigue.^5,6

About FIRDAPSE

The only FDA-approved treatment for LEMS that’s clinically proven to maintain muscle strength and improve patient reported sense of physical well-being vs placebo in clinical trials.^2-4,7

Hear from Experts

Watch LEMS experts discuss LEMS pathophysiology, clinical presentation, diagnostic challenges, and treatment options in our LEMS Video Library.

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Indication and Important Safety Information

INDICATIONS AND USAGE:

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.

CONTRAINDICATIONS

FIRDAPSE is contraindicated in patients with:

A history of seizures
Hypersensitivity to amifampridine phosphate or another aminopyridine

WARNINGS AND PRECAUTIONS

Seizures: FIRDAPSE can cause seizures. Consider discontinuation or dose-reduction of FIRDAPSE in patients who have a seizure while on treatment.

Hypersensitivity: If a hypersensitivity reaction such as anaphylaxis occurs, FIRDAPSE should be discontinued and appropriate therapy initiated.

ADVERSE REACTIONS

The most common (> 10%) adverse reactions are: paresthesia, upper respiratory tract infection, abdominal pain, nausea, diarrhea, headache, elevated liver enzymes, back pain, hypertension, and muscle spasms.

Please see full Prescribing Information for additional Important Safety Information.

To report SUSPECTED ADVERSE REACTIONS, contact Catalyst Pharmaceuticals at 1-844-347-3277 (1-844-FIRDAPSE) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

References:

Yoon CH, Owusu-Guha J, Smith A, Buschur P. Amifampridine for the management of Lambert-Eaton myasthenic syndrome: a new take on an old drug. Ann Pharmacother. 2020;54(1):56-63.
Full Prescribing Information for FIRDAPSE (amifampridine). Catalyst Pharma; 2023.
Oh SJ, Scherbakova N, Kostera-Pruszczyk A, et al; LEMS Study Group. Amifampridine phosphate (FIRDAPSE®) is effective and safe in a phase 3 clinical trial in LEMS. Muscle Nerve. 2016;53(5):717-725.
Shieh P, Sharma K, Kohrman B, Oh SJ. Amifampridine phosphate (FIRDAPSE) is effective in a confirmatory phase 3 clinical trial in LEMS. J Clin Neuromuscul Dis. 2019;20(3):111-119.
Harms L, Sieb J-P, Williams AE, et al. Long-term disease history, clinical symptoms, health status, and healthcare utilization in patients suffering from Lambert Eaton myasthenic syndrome: results of a patient interview survey in Germany. J Med Econ. 2012;15(3):521-530.
National Organization for Rare Disorders (NORD) website. Rare disease database: Lambert-Eaton myasthenic syndrome. Accessed August 18, 2022. https://rarediseases.org/rare-diseases/lambert-eaton-myasthenic-syndrome/.
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Data on file, Catalyst Pharmaceuticals.
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