• Miscellaneous immune disorders

Firdapse Generic Name & Formulations

General Description

Amifampridine 10mg; scored tabs.

Pharmacological Class

Potassium channel blocker.

How Supplied

Tabs—60, 240; Blister packs—10, 120

Generic Availability


Firdapse Indications


Lambert-Eaton myasthenic syndrome (LEMS) in patients aged ≥6yrs.

Firdapse Dosage and Administration

Adults and Children

<6yrs: not established. ≥6yrs (<45kg): Initially 5–15mg daily in 3–4 divided doses; may increase by 2.5mg every 3 or 4 days (max single dose: 10mg; max total: 40mg/day). ≥6yrs (≥45kg): Initially 15–30mg daily in 3–4 divided doses; may increase by 5mg every 3 or 4 days (max single dose: 20mg; max total: 80mg/day). Hepatic or renal impairment (CrCl 15–90mL/min), NAT2 poor metabolizers: 15mg daily (for patients ≥45kg) and 5mg daily (for patients <45kg) in 3 divided doses. Patients who require dosage <5mg increments, have difficulty swallowing, or require feeding tubes: may prepare a 1mg/mL oral suspension; see full labeling.

Firdapse Contraindications


History of seizures.

Firdapse Boxed Warnings

Not Applicable

Firdapse Warnings/Precautions


Consider dose reduction or discontinuation if seizure occurs. Discontinue and treat if anaphylaxis occurs. Hepatic or renal impairment: monitor; adjust dose or discontinue as needed. N-acetyltransferase 2 (NAT2) poor metabolizers. Elderly. Pregnancy. Nursing mothers.

Firdapse Pharmacokinetics

See Literature

Firdapse Interactions


Concomitant drugs that lower seizure threshold may increase seizure risk. Additive effects when concomitant drugs with cholinergic effects (eg, direct or indirect cholinesterase inhibitors).

Firdapse Adverse Reactions

Adverse Reactions

Paresthesia, upper RTI, abdominal pain, nausea, diarrhea, headache, elevated liver enzymes, back pain, hypertension, muscle spasms; seizures, hypersensitivity.

Firdapse Clinical Trials

See Literature

Firdapse Note

Not Applicable

Firdapse Patient Counseling

See Literature