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Generic name: dalfampridinedal-FAM-pri-deen ]
Drug class: Miscellaneous central nervous system agents

Medically reviewed by Philip Thornton, DipPharm. Last updated on Nov 5, 2021.

What is Ampyra?

Ampyra is a potassium channel blocker.

Ampyra is a prescription medicine used to improve walking in adults with multiple sclerosis (MS).

It is not known if Ampyra is safe or effective in children less than 18 years old.


Ampyra can cause a seizure (convulsions), even if you have never had one before. Taking too much dalfampridine may increase your risk of seizure. Kidney problems may also increase your risk. Your kidney function may need to be tested before you start taking this medicine.

Stop taking Ampyra and call your doctor at once if you a seizure, pain or burning when you urinate, problems with your balance, numbness or tingly feeling, or a relapse of your MS symptoms.

High doses of dalfampridine may increase your risk of seizure. Do not take more than 2 tablets in a 24-hour period. Do not use a tablet that has been broken or crushed. A broken tablet can release too much of the drug at one time.

Before taking this medicine

You should not use Ampyra if you are allergic to dalfampridine or 4-aminopyridine, or if you have:

  • moderate to severe kidney disease; or

  • if you've ever had a seizure.

Ampyra can cause a seizure, even if you never had one before. Your risk may also be higher if you have kidney problems or are older than 50.

To make sure Ampyra is safe for you, tell your doctor if you have ever had:

  • kidney disease; or

  • if you also take a form of this medicine obtained from a compounding pharmacy (fampridine, or 4-aminopyridine).

Older adults may be more sensitive to the effects of this medication.

It is not known if dalfampridine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Ask a doctor if it is safe to breastfeed while using this medicine.

Ampyra is not approved for use by anyone younger than 18 years old.

How should I take Ampyra?

Take Ampyra exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Taking too much dalfampridine may increase your risk of seizure. Space your doses 12 hours apart. Do not take more than 2 tablets in 24 hours.

You may take Ampyra with or without food.

Swallow the tablet whole and do not crush, chew, or break it. Breaking the pill may cause too much of the drug to be released at one time which can increase your risk of a seizure.

Do not use a tablet that has been crushed or broken.

Store at room temperature away from moisture and heat. Do not use past the expiration date on the label.

Dosing information

Usual Adult Dose for Multiple Sclerosis:

Maximum dose: 10 mg orally every 12 hours

-This drug may be taken with or without food.
-Tablets should be swallowed whole, and not divided, crushed, chewed, or dissolved.
-Patients should not take double or extra doses if a dose is missed.

Use: To improve walking in adult patients with multiple sclerosis (MS) demonstrated by an increase in walking speed

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose can cause confusion or seizures.

What should I avoid while taking Ampyra?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Ampyra side effects

Get emergency medical help if you have signs of an allergic reaction to Ampyra: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop taking Ampyra and call your doctor right away if you have a seizure.

Call your doctor at once if you have:

  • pain or burning when you urinate; or

  • relapse or worsening of MS symptoms.

Common Ampyra side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Ampyra?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with dalfampridine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Where can I get more information?

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Ampyra only for the indication prescribed.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.