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Dalfampridine is commonly used to improve walking in people with multiple sclerosis. Common side effects include urinary tract infection, trouble sleeping, dizziness, headache, and nausea, among others. Serious side effects are less common but can include severe allergic reactions or seizures. 

Uses

What is dalfampridine used for?

Dalfampridine is commonly used to improve walking in people with multiple sclerosis (MS). MS is a chronic condition where the immune system attacks and damages the protective coating around nerve cells, making it harder for the brain and body to work together. This can cause symptoms such as trouble walking, fatigue, muscle weakness, numbness, and vision and memory problems.

Dalfampridine may also be used for other conditions as determined by your health care provider.

How does dalfampridine work (mechanism of action)?

Dalfampridine blocks potassium channels in nerve cells. This may help damaged nerves communicate better.

How is dalfampridine supplied (dosage forms)?

Brands and other names

  • Ampyra

Dosage forms and strengths

  • 10 mg extended-release oral tablets

How should I store dalfampridine?

Dalfampridine should be stored at room temperature, between 68 F and 77 F (20 C and 25 C). It can be exposed to temperatures between 59 F and 86 F (15 C and 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. 

Side Effects

What are the most common side effects of dalfampridine?

The most common side effects of dalfampridine are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Urinary tract infection
  • Trouble sleeping
  • Dizziness
  • Headache
  • Weakness
  • Back pain
  • Trouble with balance
  • Multiple sclerosis relapse (a flare-up of symptoms)
  • Itching, tingling, or burning of the skin
  • Nose and throat irritation or throat pain
  • Stomach problems, including nausea, constipation, or upset stomach

There may be other side effects of dalfampridine that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of dalfampridine?

While less common, the most serious side effects of dalfampridine are described below, along with what to do if they happen.

Severe Allergic Reactions. Dalfampridine may cause allergic reactions, which can be serious. Stop taking dalfampridine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Seizures. Some people who have taken dalfampridine have reported having seizures, usually within the first few weeks of starting treatment. This can happen even if you have never had a seizure before. You should not take dalfampridine if you have a history of seizures. Your risk of having a seizure is higher if you take too much dalfampridine or if you have kidney problems. Your health care provider may order blood tests to check your kidney health. There are many different types of seizures and some of them are not easy to recognize. Stop taking dalfampridine and call your health care provider if you have any of the following signs that a seizure is happening or could happen.

  • Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
  • Stiffening of your arms and legs
  • Feeling anxious, nervous, confused, or a sense of dread
  • Feeling dizzy or lightheaded
  • Falling or losing consciousness

Warnings & Precautions

Who should not use dalfampridine?

Allergies to Ingredients. People who are allergic to any of the following should not take dalfampridine.

  • 4-aminopyridine
  • Ampyra
  • Dalfampridine
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific dalfampridine products they stock.

Kidney Problems. Dalfampridine should not be used if your kidneys are not working as well as they should be. If there is a concern about the health of your kidneys, your health care provider may do tests to determine if they are working well enough to take this medicine.

Seizures. Dalfampridine should not be used if you have a history of seizures.

What should I know about dalfampridine before using it?

Do not take dalfampridine unless it has been prescribed to you by a health care provider. Take it as prescribed, including specific timing for dosing, to keep your blood levels consistent.

Do not share dalfampridine with other people, even if they have the same condition as you. It may harm them.

Keep dalfampridine out of the reach of children.

Swallow the tablet whole. Do not crush, chew, divide, or dissolve the tablet, as this may cause the medicine to be released too fast and increase the risk of seizures. If you have trouble swallowing the tablet, tell your health care provider.

Dalfampridine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how dalfampridine affects you.

People who are 65 years or older can be at greater risk for some side effects from dalfampridine. Talk to your health care provider about your risks if you are in this age group.

Tell your health care provider before you start taking any other medicine, including over-the-counter (OTC) medicines.

What should I tell my health care provider before using dalfampridine?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if dalfampridine is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Kidney problems
  • Seizures
  • Any other medical conditions

Other Medicines and Supplements. Dalfampridine may interact with other medicines and supplements. Before taking dalfampridine, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how dalfampridine could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if dalfampridine passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should take dalfampridine while breastfeeding.

Interactions

Does dalfampridine interact with foods or drinks?

There are no known interactions between dalfampridine and foods or drinks.

It is unknown if drinking alcohol will affect dalfampridine.

Does dalfampridine interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking dalfampridine.

  • Cimetidine (Tagamet HB), which is a medicine used for heartburn
  • Compounded 4-aminopyridine or fampridine (specially made by a pharmacy), which contain the same active ingredient as dalfampridine

This may not be a complete list of medicines that can interact with dalfampridine. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much dalfampridine?

If you or someone else has used too much dalfampridine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of dalfampridine?

If you miss a dose, skip the missed dose. Take the next dose when you normally would. Do not take double or extra doses.