Amifampridine (Oral route)

Brand Names:

  • Firdapse
  • Ruzurgi

Dosage Forms:

  • Tablet

Classifications:

Therapeutic—

Central Nervous System Agent

Pharmacologic—

Potassium Channel Blocker

Uses of This Medicine:

Amifampridine is used to treat Lambert-Eaton myasthenic syndrome (LEMS), a rare autoimmune disease, wherein the immune system attacks the connection between the nerve and muscle (neuromuscular junction) and blocks the ability of the nerve cells to send signals to the muscle cells, leading to muscle weakness of the arms or legs.

This medicine is available only with your doctor's prescription.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Appropriate studies have not been performed on the relationship of age to the effects of Firdapse® in children and Ruzurgi® in children younger than 6 years of age. Safety and efficacy have not been established.

Older adults—

No information is available on the relationship of age to the effects of Ruzurgi® in geriatric patients.

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of Firdapse® in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving this medicine.

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Acetophenazine
  • Aclidinium
  • Acrivastine
  • Alcaftadine
  • Alfentanil
  • Amantadine
  • Ambenonium
  • Amdinocillin
  • Amdinocillin Pivoxil
  • Amineptine
  • Aminophylline
  • Amitriptylinoxide
  • Amoxapine
  • Amphetamine
  • Ampicillin
  • Anisotropine
  • Antazoline
  • Atropine
  • Azatadine
  • Azelastine
  • Azlocillin
  • Bacampicillin
  • Baclofen
  • Belladonna Alkaloids
  • Benperidol
  • Benzhydrocodone
  • Benzphetamine
  • Bepotastine
  • Bornaprine
  • Bromodiphenhydramine
  • Bromperidol
  • Brompheniramine
  • Buclizine
  • Bupivacaine
  • Butorphanol
  • Butriptyline
  • Butylscopolamine
  • Carbenicillin
  • Carbinoxamine
  • Chlorambucil
  • Chlorotrianisene
  • Chlorpheniramine
  • Chlorphenoxamine
  • Cimetropium
  • Cinnarizine
  • Clemastine
  • Clemizole
  • Clidinium
  • Cloxacillin
  • Cocaine
  • Codeine
  • Conjugated Estrogens
  • Cyclacillin
  • Cyclizine
  • Cyclopentolate
  • Cyclosporine
  • Cyproheptadine
  • Darifenacin
  • Demecarium
  • Dexbrompheniramine
  • Dexchlorpheniramine
  • Dextroamphetamine
  • Dibenzepin
  • Dicloxacillin
  • Dicyclomine
  • Dienestrol
  • Diethylstilbestrol
  • Difenoxin
  • Dihydrocodeine
  • Dimenhydrinate
  • Dimethindene
  • Diphenhydramine
  • Diphenylpyraline
  • Distigmine
  • Dixyrazine
  • Donepezil
  • Dothiepin
  • Doxylamine
  • Echothiophate
  • Edrophonium
  • Emedastine
  • Enflurane
  • Epinastine
  • Esterified Estrogens
  • Estradiol
  • Estramustine
  • Estriol
  • Estrone
  • Estropipate
  • Ethinyl Estradiol
  • Ethopropazine
  • Fentanyl
  • Fesoterodine
  • Flavoxate
  • Floxacillin
  • Flunarizine
  • Glycopyrrolate
  • Guanidine
  • Hetacillin
  • Homatropine
  • Hydrocodone
  • Hydromorphone
  • Hydroxyamphetamine
  • Hyoscyamine
  • Indalpine
  • Iprindole
  • Isoflurophate
  • Isoniazid
  • Isopropamide
  • Ketamine
  • Ketotifen
  • Levocabastine
  • Levomilnacipran
  • Levorphanol
  • Lidocaine
  • Lindane
  • Lisdexamfetamine
  • Lithium
  • Lofepramine
  • Loxapine
  • Mebeverine
  • Mebhydrolin
  • Meclizine
  • Mefenamic Acid
  • Melitracen
  • Melperone
  • Mepenzolate
  • Meperidine
  • Mestranol
  • Methamphetamine
  • Methantheline
  • Methdilazine
  • Methicillin
  • Methixene
  • Methotrimeprazine
  • Methylphenidate
  • Metopimazine
  • Mezlocillin
  • Milnacipran
  • Morphine
  • Nalbuphine
  • Nalidixic Acid
  • Neostigmine
  • Niaprazine
  • Nortriptyline
  • Olopatadine
  • Opipramol
  • Orphenadrine
  • Oxacillin
  • Oxatomide
  • Oxycodone
  • Oxymorphone
  • Penicillin G
  • Penicillin V
  • Pentazocine
  • Perazine
  • Periciazine
  • Phenindamine
  • Pheniramine
  • Phenylpropanolamine
  • Phenyltoloxamine
  • Physostigmine
  • Pinaverium
  • Piperacillin
  • Pipotiazine
  • Pirenzepine
  • Pivampicillin
  • Pizotyline
  • Polyestradiol Phosphate
  • Procaine
  • Promazine
  • Promestriene
  • Propantheline
  • Propicillin
  • Propiverine
  • Propizepine
  • Propoxyphene
  • Pyrilamine
  • Quinestrol
  • Remifentanil
  • Rivastigmine
  • Scopolamine
  • Sibutramine
  • Sufentanil
  • Sulbenicillin
  • Sultamicillin
  • Tacrine
  • Tapentadol
  • Temocillin
  • Theophylline
  • Thiethylperazine
  • Thiopropazate
  • Thioproperazine
  • Thonzylamine
  • Tianeptine
  • Tibolone
  • Ticarcillin
  • Timiperone
  • Tiotropium
  • Tramadol
  • Trifluoperazine
  • Triflupromazine
  • Trimeprazine
  • Tripelennamine
  • Triprolidine
  • Tropicamide
  • Trospium
  • Umeclidinium
  • Valethamate

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Kidney disease or
  • Liver disease—Use with caution. The effects may be increased because of the slower removal of the medicine from the body.
  • Seizures, history of—Should not be used in patients with this condition.

Proper Use of This Medicine:

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine comes with a Medication Guide and patient information leaflet. Read and follow these instructions carefully. Ask your doctor if you have any questions.

You may take this medicine with or without food.

The tablets may be divided in half at the score (line at the center) if you need less than a full tablet to get the right dose.

If your child cannot swallow the Ruzurgi® tablet or needs to take it using a feeding tube, you may prepare a suspension. Mix three tablets with 30 milliliters (mL) of water in a 30-mL container, then shake the mixture well for 30 seconds. You may give the dose using an oral syringe or feeding tube. Shake the medicine well before giving each dose.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For Lambert-Eaton myasthenic syndrome:
      • Fidarpse®:
        • Adults—At first, 15 milligrams (mg) to 30 mg given in 3 to 4 divided doses per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 80 mg total per day.
        • Children—Use and dose must be determined by your doctor.
      • Ruzurgi®:
        • Children 6 to 16 years of age weighing 45 kilograms (kg) or more—Dose is based on body weight and must be determined by your doctor. At first, 15 milligrams (mg) to 30 mg given 2 to 3 divided doses per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 100 mg total per day.
        • Children 6 to 16 years of age weighing less than 45 kg—Dose is based on body weight and must be determined by your doctor. At first, 7.5 mg to 15 mg given 2 to 3 divided doses per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 50 mg total per day.
        • Children less than 6 years of age—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Store Ruzurgi® tablets at room temperature for up to 3 months. Keep Ruzurgi® suspension in the refrigerator for up to 24 hours. Throw away any unused liquid after 24 hours.

Precautions While Using This Medicine:

It is very important that your doctor check your or your child's progress at regular visits to make sure this medicine is working properly.

This medicine may increase your risk for seizures and should not be given to patients who have had seizures.

This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and requires immediate medical attention. Tell your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common
Arm or leg pain
bladder pain
bloating or swelling of the face, arms, hands, lower legs, or feet
bloody or cloudy urine
blurred vision
burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
chest pain
chills
cough
cough producing mucus
diarrhea
difficult, burning, or painful urination
difficulty breathing or swallowing
dizziness
fever
frequent urge to urinate
general feeling of discomfort or illness
headache
hoarseness
joint pain
loss of appetite
lower back or side pain
muscle pains, spasms, or weakness
nausea
nervousness
pounding in the ears
rapid weight gain
runny nose
shivering
slow or fast heartbeat
sneezing
sore throat
sweating
swollen, painful, or tender lymph glands in the neck, armpit, or groin
tightness of the chest
trouble sleeping
unusual tiredness or weakness
unusual weight gain or loss
vomiting

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
Back pain
blindness
constipation
decreased vision
discouragement
falls
feeling cold
feeling sad or empty
heartburn
irritability
lack or loss of strength
loss of interest or pleasure
pale skin
stomach pain
trouble concentrating
troubled breathing with exertion
unusual bleeding or bruising

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.


Last Updated: 9/5/2019

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

All rights reserved.

 

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.
All rights reserved.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.