Ampyra (Dalfampridine) - Oral

What Is Ampyra?

Ampyra (dalfampridine) is a prescription medication that's used to improve walking in people with multiple sclerosis (MS). Ampyra is a potassium channel blocker. Potassium channels are proteins responsible for moving potassium in and out of cells.

By blocking potassium channels, Ampyra is thought to work by helping damaged neurons (nerve cells) work better.

Ampyra is available as a tablet. The Food and Drug Administration (FDA) hasn't assigned any black box warnings to this medication.

Drug Facts

Generic Name: Dalfampridine

Brand Name(s): Ampyra

Drug Availability: Prescription

Therapeutic Classification: Potassium channel blocker

Available Generically: Yes

Controlled Substance: No

Administration Route: Oral (by mouth)

Active Ingredient: Dalfampridine

Dosage Form(s): Tablet

What Is Ampyra Used For?

Ampyra improves walking in people with multiple sclerosis (MS).

In MS, the immune system (the body's defense system) attacks the central nervous system (CNS) by mistake. The CNS includes your brain and spinal cord. The damaged neurons (nerve cells) may lead to the following symptoms:

  • Behavioral changes
  • Tiredness or low energy
  • Vision changes
  • Weakness
  • Worsening memory

MS may also cause movement difficulties, such as walking. Ampyra may help with this.

How to Take Ampyra

Take Ampyra by mouth twice daily—roughly 12 hours in between doses. Ampyra can be taken with or without food.

Take Ampyra as a whole tablet. Don't crush, chew, or split it. Also, Ampyra should not be dissolved by placing the tablet in water or other liquids.

Storage

When you receive Ampyra from the pharmacy, store the medication at 77 degrees Fahrenheit (F). Ampyra can also be safely stored between 59 degrees to 86 degrees F for short periods. Based on these storage temperatures, room temperature should be okay.

To be safe, you may also place Ampyra in a locked cabinet or closet to keep your medications out of reach of children and pets.

If you plan to travel with Ampyra, get familiar with your final destination's regulations. In general, be sure to make a copy of your Ampyra prescription. Keep your medication in its original container from your pharmacy with your name on the label. Ask your pharmacist or healthcare provider if you have any questions about traveling with your medicine.

Visit the FDA's website to know where and how to discard all unused and expired drugs. You can also find disposal boxes in your area. Ask your pharmacist or healthcare provider if you have any questions about the best ways to dispose of your medications.

Off-Label Uses

Currently, there are no off-label uses for Ampyra.

How Long Does Ampyra Take to Work?

You might notice an improvement in your walking in as soon as six weeks.

What Are the Side Effects of Ampyra?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Common side effects of Ampyra may include:

Severe Side Effects

A potential severe side effect with Ampyra is a severe allergic reaction. Symptoms of a severe allergic reaction may include breathing difficulties, swelling, and hives.

Ampyra may also raise your risk of seizures.

Contact your healthcare provider right away if you develop any of these serious side effects. Call 911 if your symptoms feel life-threatening.

Long-Term Side Effects

Possible long-term side effects of Ampyra are very similar to its common and serious side effects. However, in one case report, problems with short-term memory might be possible for at least one year after taking a high 300 milligram (mg) dose of Ampyra. Another potential long-term side effect of this high Ampyra dose is trouble learning new tasks.

Report Side Effects

Ampyra may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Ampyra Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

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 (extended release tablets):
    • For walking impairment:
      • Adults—10 milligrams (mg) 2 times a day (taken at least 12 hours apart). Do not take more than 2 tablets in a 24-hour period.
      • Children—Use and dose must be determined by your doctor.

Modifications

The following modifications (changes) should be kept in mind when using Ampyra:

Severe allergic reaction: If you have a severe allergic reaction to Ampyra, your healthcare provider wouldn't recommend Ampyra for you.

Pregnancy: In animal studies, Ampyra was found to have adverse (negative) effects on the fetus. There isn't enough data about the safety and effectiveness of Ampyra in pregnant people and on the unborn fetus. Discuss with your healthcare provider if you are or plan to become pregnant. They will help you weigh the benefits and risks of taking Ampyra during pregnancy.

Breastfeeding: In animal studies, Ampyra was linked to adverse effects on the growth of nursing babies. In humans, however, there are no available safety and effectiveness data about Ampyra on nursing babies. Talk with your healthcare provider if you plan to breastfeed. Your healthcare provider will help you weigh the benefits and harms of taking Ampyra while nursing. They will also discuss different ways to feed your baby.

Older adults over 65: Reports suggest no safety and effectiveness differences for Ampyra between older and younger adults. In general, however, older adults may have some kidney impairment. Therefore, caution is recommended for older adults.

Children: There is limited safety and effectiveness information about Ampyra in children.

Kidney problems: Individuals with kidney problems may not be able to clear medication from their bodies as easily. This means the medicine stays in the body longer and can have increased side effects. For this reason, if you have moderate to severe kidney impairment, your healthcare provider will likely not prescribe Ampyra.

Seizures: Ampyra may raise your risk of seizures. Ampyra isn't recommended for you if you have a history of seizures. If you develop seizures while taking Ampyra, your healthcare provider will likely stop this medication.

Missed Dose

If you accidentally forgot your Ampyra dose, skip the missed dose and take the following dose at your next scheduled dosing time. Don't try to double up to make up for the missed dose.

Try to find ways to help yourself remember to routinely take your medication that works for you. If you miss too many doses, Ampyra might be less effective.

Overdose: What Happens If I Take Too Much Ampyra?

The symptoms of a suspected overdose with Ampyra may include:

  • Confusion
  • Decreased awareness or alertness
  • Memory problems
  • Seizures
  • Speech problems
  • Sweating
  • Uncontrollable tremors or shaking
  • Weakness

In reference to one case report, memory problems may still be a concern for at least one year after an overdose with 300 milligrams of Ampyra.

If you think that you're experiencing an overdose or life-threatening symptoms, seek immediate medical attention.

What Happens If I Overdose on Ampyra?

If you think you or someone else may have overdosed on Ampyra, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Ampyra, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Check with your doctor right away if you have seizures while taking this medicine.

Do not take dalfampridine together with other aminopyridine medicines (eg, compounded 4-AP, fampridine). Taking these medicines together will increase the chance for more serious side effects.

This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require 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.

This medicine may make you dizzy, lightheaded, or feel a constant movement of self or surroundings. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

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.

What Are Reasons I Shouldn’t Take Ampyra?

Before taking Ampyra, talk with your healthcare provider if any of the following applies to you:

  • Severe allergic reaction: If you have a severe allergic reaction to Ampyra or any of its components (ingredients), then Ampyra isn't an ideal option for you.
  • Seizures: Ampyra should be avoided if you have a history of seizures. Ampyra should be discontinued if you develop seizures while taking the medication.
  • Kidney problems: If you have moderate to severe kidney impairment, Ampyra isn't recommended for you.
  • Pregnant or nursing people: There is no human safety and effectiveness information about taking Ampyra in pregnancy or while nursing. However, in animal studies, there were adverse effects on the unborn fetus and nursing baby. Talk with your healthcare provider to weigh the benefits and risks of taking Ampyra while pregnant or nursing.
  • Children: There is no safety and effectiveness data about Ampyra for children.
  • Older adults over 65: Reports suggest that Ampyra has no safety and effectiveness differences in older and younger adults. Some older adults may tend to have some kidney impairment. As a result, use Ampyra with caution.

What Other Medications Interact With Ampyra?

The medication 4-aminopyridine (4-AP) is very similar to Ampyra. Therefore, avoid combining Ampyra with other versions of 4-AP, such as Firdapse (amifampridine), for Lambert-Eaton myasthenic syndrome (LEMS). In LEMS, the immune system (the body's defense system) mistakenly attacks the neuromuscular junction (where the nerve cells meet with the muscles).

Also, use caution with organic cation transporter 2 (OCT2) inhibitors—like Tagamet (cimetidine) for heartburn. OCT2 is a protein responsible for moving medications—like Ampyra—around the body. OCT2-inhibiting medications may lead to a build-up of Ampyra in your body. Higher amounts of Ampyra are linked to more side effects, such as seizures.

Talk with your pharmacist or healthcare provider for more detailed information about medication interactions with Ampyra.

And be sure to talk with your healthcare provider about any other medicines you take or plan to take, including over-the-counter, nonprescription products, vitamins, herbs, or plant-based medicines.

What Medications Are Similar?

Presently, the potassium channel blocker class only includes Ampyra that's used to improve walking in people with multiple sclerosis (MS).

Frequently Asked Questions

  • Where is Ampyra available?

    Ampyra is probably not available at your local retail pharmacy. Your healthcare provider may need to send a prescription into a specialty pharmacy for you.

  • How much does Ampyra cost?

    Ampyra is available as a generic product. So, this will save you on cost. Since Ampyra and its generic are limited to specialty pharmacies, however, they might be expensive.


    If cost is a concern, Ampyra's manufacturer does offer support services. For eligibility questions, visit Acorda's website or call 1-888-881-1918. You can also visit RxAssist, which might help. RxAssist lists a number of assistance programs for various medications.

  • Why am I not supposed to crush, chew, split, or dissolve Ampyra tablets?

    Ampyra is an extended-release (ER) tablet. So, it releases the medication slowly over time. If you crush, chew, split, or dissolve Ampyra, the tablet will release the medication too quickly and raise your seizure risk.

How Can I Stay Healthy While Taking Ampyra?

If you're taking Ampyra, chances are multiple sclerosis (MS) has been negatively affecting your quality of life. You may have tried different approaches or treatments. While living with MS does have its challenges, there are ways to help improve your quality of life. Refer below for some general tips to support your health:

  • Take MS-related medications as recommended by your healthcare provider.
  • Stay in touch with your healthcare provider to let them know how Ampyra is working for you.
  • Share your MS condition with loved ones when you're ready. Having a solid social support network is essential.
  • Consider support groups. You can find support groups on the National Multiple Sclerosis Society's website.
  • Consider working with a mental health professional to help you find coping strategies to change how you think, feel, react, or respond to living with MS.
  • Become comfortable saying "no" to take care of yourself and prevent overextending yourself.
  • Add in more time to plan for your travels and the holidays.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. Ampyra label.

  2. Kuang Q, Purhonen, P, Hebert H. Structure of potassium channels. Cell Mol Life Sci. 2015;72:3677-3693. doi:10.1007/s00018-015-1948-5

  3. ScienceDirect. Potassium channel.

  4. National Organization for Rare Disorders. Multiple sclerosis.

  5. Finkelsztejn A. Multiple sclerosis: overview of disease-modifying agents. Perspect Medicin Chem. 2014;6:65-72. doi:10.4137/PMC.S13213

  6. MedlinePlus. Dalfampridine.

  7. National Library of Medicine. Dalfampridine.

  8. Food and Drug Administration. Firdapse label.

  9. ScienceDirect. Organic cation transporter 2.

  10. Food and Drug Administration. Orange book: approved drug products with therapeutic equivalence evaluations.

By Ross Phan, PharmD, BCACP, BCGP, BCPS
Ross is a writer for Verywell with years of experience practicing pharmacy in various settings. She is also a board-certified clinical pharmacist and the founder of Off Script Consults.