Amifampridina (amifampridine phosphate)

Para qué se usa Amifampridina

Cita de la sección «Indications and Usage» (indicaciones y uso) de la etiqueta aprobada por la FDA. Se muestra en inglés, tal como la publica la FDA.

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.

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Leer la etiqueta completa en DailyMed →

Etiqueta citada: la de la presentación más común (tablet, oral), Firdapse, Catalyst Pharmaceuticals, Inc.; abarca 1 producto del directorio NDC de la FDA. Las citas sobre efectos secundarios, interacciones, dosis y embarazo de abajo vienen de esta misma etiqueta.

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Efectos secundarios de Amifampridina

Cita de la sección «Adverse Reactions» (reacciones adversas) de la etiqueta aprobada por la FDA. Se muestra en inglés. Avise a su médico de cualquier efecto secundario que le preocupe.

The following serious adverse reactions are described elsewhere in the labeling: Seizures [see Warnings and Precautions (5.1)] Hypersensitivity [see Warnings and Precautions (5.2)] 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.

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(6) 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. 6.1 Clinical Trials Experience Adults Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In controlled and uncontrolled clinical trials (Study 1 and 2) in patients with LEMS [see Clinical Studies (14)], 63 patients were treated with FIRDAPSE, including 40 patients treated for more than 6 months, and 39 patients treated for more than 12 months. In an expanded access program, 139 patients with LEMS were treated with FIRDAPSE, including 102 patients treated for more than 6 months, 77 patients treated for more than 12 months, and 53 patients treated for more than 18 months. In the expanded access program, patients were treated with FIRDAPSE with up to 100 mg daily in divided doses. Study 1 was a double-blind, placebo-controlled, randomized discontinuation study in adults with LEMS. Following an initial open- label run-in phase (up to 90 days), patients were randomized to either continue FIRDAPSE treatment or transition to placebo, for a 14-day double-blind phase. Following final assessments, patients were allowed to resume FIRDAPSE treatment for up to 2 years (open-label long-term safety phase of the study). During the open-label run-in phase of Study 1, 53 patients received FIRDAPSE for an average of 81 days at a mean daily dosage of 50.5 mg/day. The mean patient age was 52.1 years and 66% were female. There were 42 patients who had no prior exposure to FIRDAPSE at the initiation of this study. Table 2 shows adverse reactions with an incidence of 5% or greater occurring in the 42 LEMS patients newly initiated on treatment with FIRDAPSE during the run-in phase of the study. Table 2.

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Esto es solo una parte de la sección. Leer la etiqueta completa en DailyMed →

Interacciones de Amifampridina

Cita de la sección «Drug Interactions» (interacciones) de la etiqueta aprobada por la FDA. Se muestra en inglés. Dígale a su farmacéutico todos los medicamentos, vitaminas y productos herbales que toma.

Drugs that lower seizure threshold: Concomitant use may lead to an increased risk of seizures. (7.1) Drugs with cholinergic effects (e.g., direct or indirect cholinesterase inhibitors): Concomitant use may increase the cholinergic effects of FIRDAPSE and of those drugs and increase the risk of adverse reactions.

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(7.2) 7.1 Drugs that Lower Seizure Threshold The concomitant use of FIRDAPSE and drugs that lower seizure threshold may lead to an increased risk of seizures [see Warnings and Precautions (5.1)]. The decision to administer FIRDAPSE concomitantly with drugs that lower the seizure threshold should be carefully considered in light of the severity of the associated risks. 7.2 Drugs with Cholinergic Effects The concomitant use of FIRDAPSE and drugs with cholinergic effects (e.g., direct or indirect cholinesterase inhibitors) may increase the cholinergic effects of FIRDAPSE and of those drugs and increase the risk of adverse reactions.

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Leer la etiqueta completa en DailyMed →

Dosis de Amifampridina

Cita de la sección «Dosage and Administration» (dosis y administración) de la etiqueta aprobada por la FDA. Se muestra en inglés. Su dosis es la que le receta su médico: no la cambie por su cuenta.

Administer orally in divided doses (3 to 5 times daily). (2.1) The recommended starting dosage for adults (any weight) and pediatric patients weighing 45 kg or more is 15 mg to 30 mg daily, in divided doses. (2.1) Dosage can be increased by 5 mg daily every 3 to 4 days. (2.1) The maximum single dose is 20 mg. (2.1) Dosage is not to exceed a maximum of 100 mg daily.

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(2.1) The recommended starting dosage for pediatric patients weighing less than 45 kg is 5 mg to 15 mg daily, in divided doses. (2.1) Dosage can be increased by 2.5 mg daily every 3 to 4 days. (2.1) The maximum single dose is 10 mg. (2.1) Dosage is not to exceed a maximum of 50 mg daily. (2.1) The recommended starting dosage for adult and pediatric patients with renal impairment, hepatic impairment, and in known N-acetyltransferase 2 (NAT2) poor metabolizers is the lowest recommended initial daily dosage (2.1, 2.2, 2.3, 2.4) For patients with a dosage adjustment of less than 5 mg increments, or who have difficulty swallowing, or require feeding tube, a l mg/mL suspension can be prepared. (2.5) 2.1 Dosage Information The recommended oral dosage of FIRDAPSE for adults and pediatric patients 6 years of age and older is included in Table 1. For pediatric patients, the recommended dosing regimen is dependent on body weight. Dosage should be increased every 3 to 4 days based on clinical response and tolerability. Titration increments should not exceed those shown in Table 1. Table 1: Recommended Oral Dosage for the Treatment of LEMS in Adults and Pediatric Patients 6 Years of Age and Older * See Dosage and Administration (2.5) for a method to achieve these doses Age and Body Weight Initial Daily Dosage * Titration Regimen Maximum Single Dose Maximum Total Daily Maintenance Dosage Adults (any weight) Pediatric patients weighing 45 kg or more 15 mg to 30 mg daily, in 3 to 5 divided doses Increase total daily dosage by 5 mg every 3 or 4 days 20 mg 100 mg Given in divided doses Pediatric patients weighing less than 45 kg 5 mg to 15 mg daily, in 3 to 5 divided doses Increase total daily dosage by 2.5 mg every 3 or 4 days 10 mg 50 mg Given in divided doses Missed Dose If a dose is missed, patients should not take double or extra doses. 2.2 Patients with Renal Impairment The recommended starting dosage of FIRDAPSE in patients with renal impairment [creatinine clearance (CLcr) 15 to 90 mL/min] is the lowest recommended initial daily dosage (i.e., 15 mg daily for pediatric patients weighing 45 kg or more and for adults, and 5 mg daily for pediatric patients weighing less than 45 kg) taken orally in divided doses.

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Esto es solo una parte de la sección. Leer la etiqueta completa en DailyMed →

Amifampridina en el embarazo

Cita de la parte sobre embarazo (Pregnancy) de la etiqueta aprobada por la FDA. Se muestra en inglés. Pregunte a su médico antes de tomar cualquier medicamento si está embarazada o planea estarlo.

Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to FIRDAPSE during pregnancy.

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Physicians are encouraged to enroll pregnant patients, or pregnant women may register themselves in the registry by calling 855- 212-5856 (toll-free), using the Fax number 877-867-1874 (toll-free), by contacting the Pregnancy Coordinating Center at firdapsepregnancyregistry@ubc.com, or by visiting the study website www.firdapsepregnancystudy.com. Risk Summary There are no data on the developmental risk associated with the use of FIRDAPSE in pregnant women. In animal studies, administration of amifampridine phosphate to rats during pregnancy and lactation resulted in developmental toxicity (increase in stillbirths and pup deaths, reduced pup weight, and delayed sexual development) at doses associated with maternal plasma drug levels lower than therapeutic drug levels (see Animal Data). In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. Data Animal Data Oral administration of amifampridine phosphate (0, 7.5, 22.5, or 75 mg/kg/day) to female rats prior to and during mating and continuing throughout organogenesis produced no adverse effects on embryofetal development. The highest dose tested is approximately 4 times the maximum recommended human dose (MRHD) of amifampridine (100 mg/day) on a body surface area (mg/m 2) basis. Oral administration of amifampridine phosphate (0, 9, 30, or 57 mg/kg/day) to pregnant rabbits throughout organogenesis produced no adverse effects on embryofetal development. The highest dose tested is approximately 6 times the MRHD of amifampridine on a body surface area (mg/m 2) basis. Oral administration of amifampridine phosphate (0, 7.5, 22.5, or 75 mg/kg/day) to female rats throughout pregnancy and lactation resulted in an increase in stillbirths and pup deaths, reduced pup weight, and delayed sexual development in female pups at the mid and high doses tested. The no-effect dose (7.5 mg/kg/day amifampridine phosphate) for adverse developmental effects is associated with a plasma amifampridine exposure (AUC) less than that in humans at the MRHD of amifampridine.

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Leer la etiqueta completa en DailyMed →

Cuándo no se debe usar Amifampridina

Cita de la sección «Contraindications» (contraindicaciones) de la etiqueta aprobada por la FDA. Se muestra en inglés.

FIRDAPSE is contraindicated in patients with: A history of seizures [see Warnings and Precautions (5.1)] Hypersensitivity to amifampridine phosphate or another aminopyridine [see Warnings and Precautions (5.2)] FIRDAPSE is contraindicated in patients with: A history of seizures (4) Hypersensitivity to amifampridine or another aminopyridine (4)

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Leer la etiqueta completa en DailyMed →

Sobredosis de Amifampridina

Cita de la sección «Overdosage» (sobredosis) de la etiqueta aprobada por la FDA. Se muestra en inglés. Si alguien pudo haber tomado demasiado, llame a Poison Help al 1-800-222-1222 (o al 911 en una emergencia).

Overdose with FIRDAPSE was not reported during clinical studies. In a case report, a 65-year-old patient with LEMS inadvertently received a total daily amifampridine dose of 360 mg/day (approximately 4 times the maximum recommended total daily dose) and was hospitalized for general weakness, paresthesia, nausea, vomiting, and palpitations. The patient developed convulsions and paroxysmal supraventricular tachycardia, and four days after admission, experienced cardiac arrest.

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The patient was resuscitated and ultimately recovered following withdrawal of amifampridine. Patients with suspected overdose with FIRDAPSE should be monitored for signs or symptoms of exaggerated FIRDAPSE adverse reactions or effects, and appropriate symptomatic treatment instituted immediately.

— Etiqueta de la FDA: Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026. Leer la etiqueta completa en DailyMed →

Presentaciones y vía de administración

Empresas que tienen este medicamento

Empresas en el directorio NDC de la FDA: la empresa que aparece en el envase (fabricante o distribuidor), con su número de productos con receta.

• Catalyst Pharmaceuticals, Inc.1 producto

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• NDA: Solicitud de nuevo medicamento (NDA): así se aprueba un medicamento nuevo, normalmente de marca.

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• Catalyst Pharmaceuticals, Inc.Fabricante o distribuidor
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Fuentes

1. Etiqueta aprobada por la FDA en DailyMed (Biblioteca Nacional de Medicina) — Firdapse, Catalyst Pharmaceuticals, Inc., vigente desde el 16 de abril de 2026; vía openFDA, datos de la FDA exportados el 30 de octubre de 2026, consultados el 31 de octubre de 2026
2. NDC Directory (openFDA) — Administración de Alimentos y Medicamentos de los EE. UU. (FDA), datos de la FDA exportados el 30 de octubre de 2026, consultados el 31 de octubre de 2026
3. Drugs@FDA (openFDA) — Administración de Alimentos y Medicamentos de los EE. UU. (FDA), datos de la FDA exportados el 30 de octubre de 2026, consultados el 31 de octubre de 2026
4. Drug recall enforcement reports (openFDA) — Administración de Alimentos y Medicamentos de los EE. UU. (FDA), datos de la FDA exportados el 27 de octubre de 2026, consultados el 31 de octubre de 2026
5. Drug shortages (openFDA) — Administración de Alimentos y Medicamentos de los EE. UU. (FDA), datos de la FDA exportados el 30 de octubre de 2026, consultados el 31 de octubre de 2026
6. Nombre en español: RxNorm (Biblioteca Nacional de Medicina de EE. UU.) y Wikidata, vinculados por el identificador RxNorm (RxCUI) del principio activo, sin coincidencias aproximadas.

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