Ampyra (dalfampridine) for multiple sclerosis
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What is Ampyra for MS?
Ampyra (dalfampridine) is an approved oral medication used to improve walking ability in people with multiple sclerosis (MS).
Movement problems, specifically difficulty walking or frequent stumbling, are estimated to affect nearly 9 out of 10 patients with the neurodegenerative disease.
This brand-name medication is marketed by Merz Therapeutics, which bought the assets of the treatment’s developer, Acorda Therapeutics, in July 2024. However, several generic forms of Ampyra have been approved by the U.S. Food and Drug Administration (FDA) since 2017.
Therapy Snapshot
| Brand Name: | Ampyra |
| Chemical Name: | Dalfampridine |
| Usage: | Symptom management therapy to improve walking ability |
| Administration: | Oral tablets |
How does Ampyra work?
In MS, inflammation causes damage to nerve cells, which interferes with their ability to send electrical signals. At a chemical level, a nerve cell sends electrical impulses by regulating the flow of certain electrically charged ions (salts), particularly sodium and potassium, in and out of the cell.
Ampyra’s mechanism of action is not completely understood, but the medication is known to block the activity of potassium channels — specialized proteins that nerve cells use to control the flow of potassium ions.
In animal models, blocking these channels with Ampyra has been shown to improve the conduction of electrical signals in damaged neurons. The medication is thought to work mainly by increasing signals from damaged neurons, helping to correct some of the neuronal dysfunction and impairments caused by MS-related damage.
Who can take Ampyra?
The FDA approved Ampyra in 2010 to improve walking in adults with MS. It has demonstrated benefits in all types of MS.
The medication is also approved in the European Union and other countries such as Brazil, Canada, and Australia, where it is sold under the brand name Fampyra.
Who should not take Ampyra?
Ampyra is not recommended, per its prescribing information, for people with:
- moderate or severe kidney impairment
- a history of seizures
- a history of allergic reactions to the medication or other medicines with the same active ingredient
How is Ampyra administered?
Ampyra is available in film-coated, extended-release tablets containing 10 mg of dalfampridine. These capsules are white and oval, and are engraved with “A10” on one side.
The maximum recommended dose is 10 mg twice daily, or two tablets a day, taken orally about 12 hours apart. Higher doses do not yield additional benefits, and instead have been linked with an increased risk of adverse reactions, such as seizures.
The medication may be taken with or without food. Tablets must be swallowed whole, and not divided, crushed, chewed, or dissolved. Patients should not take extra doses if they miss a dose.
| Administration | Oral tablets |
| Dosage | 10 mg |
| Timing | Twice daily, about 12 hours apart |
Ampyra in clinical trials
Ampyra’s approval was supported by data from two Phase 3 clinical trials that collectively enrolled 540 people with walking difficulties due to MS. In both studies, participants were recruited at sites in the U.S. and Canada.
These patients first underwent one week of screening, and two weeks in which they were given a placebo — unknown to the participants, but known to the people running the study. Then, participants were randomly assigned to receive either Ampyra (10 mg twice daily) or a placebo.
The first trial (NCT00127530) enrolled 301 participants who took Ampyra or a placebo for 14 weeks. Nearly half had secondary progressive MS (49%). The remaining patients had relapsing-remitting MS (29%) and primary progressive MS (22%). The average duration of disease was more than 12 years.
Trial results showed that significantly more patients on Ampyra were considered responders, compared with those on a placebo (35% vs. 8%). To be considered a responder, a patient had to walk faster in at least three of four visits during the randomized portion, compared with the maximum speed recorded in off-treatment visits.
Over the 14 weeks, the average walking speed increased by about 25% among responders, compared with increases of 4.7% in the placebo group and 7.5% in the non-responder group. Responders also had less self-reported walking disability, increased muscle strength, and reduced spasticity scores.
The second trial (NCT00483652) enrolled 239 patients who received their assigned treatment for nine weeks. As in the previous trial, almost half of the participants had SPMS (47.1%), and their mean disease duration was 13.1 years.
Results from this trial were generally similar to the first study. Significantly more patients responded to the medication than a placebo (42.9% vs. 9.3%), and those who responded experienced a 24.7% increase in their walking speed. That jump compared with increases in the range of 6–8% in the placebo and non-responder groups.
Treatment benefits were seen in both trials irrespective of MS type, other MS treatments, degree of impairment, age, gender, or body mass index.
Common side effects of Ampyra
The most common side effects of Ampyra include:
- urinary tract infection
- insomnia
- dizziness
- headache
- nausea
- generalized weakness
- back pain
- throat pain
- trouble with balance
- multiple sclerosis relapse
- tingling or pricking sensations
- the common cold
- constipation
- indigestion
Seizures
Ampyra may cause seizures, and the risk of such episodes is increased when patients exceed the maximum recommended dosage. The therapy should not be given to anyone with a history of seizures. If a seizure occurs, treatment should be stopped permanently.
Kidney problems
Because Ampyra is eliminated from the body through the kidneys, patients with kidney impairment may have dalfampridine levels in circulation that far exceed the recommended levels. These higher levels are linked with a heightened risk of seizures.
For this reason, patients with moderate to severe kidney impairments should not be given this medication. Moreover, the potential risks should be discussed when deciding whether or not to commence treatment in those with mild kidney impairment.
Allergic reactions
Allergic reactions to Ampyra have been reported. If such a reaction occurs, Ampyra should be stopped and patients should seek immediate medical care.
Pregnancy and breastfeeding
Animal studies suggest that Ampyra may cause harm to a developing fetus, although no clinical trials have adequately studied its effects in pregnant people. Patients who are or plan to become pregnant while on Ampyra should discuss the medication’s use with their healthcare team.
It also is unknown if the medication can pass through breast milk. According to Ampyra’s label, patients should decide whether to breastfeed or take the medication.
Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
FAQs about Ampyra
Ampyra was approved by the U.S. Food and Drug Administration in January 2010. It is indicated for easing walking difficulties associated with multiple sclerosis.
Ampyra has not been well-studied in pregnant people, but data from animal studies suggest it can cause harm to a developing fetus. Patients who become or plan to become pregnant while on the medication should discuss this issue with their healthcare provider.
Alcohol is not known to directly interact with Ampyra, but it may worsen certain side effects of the medication or exacerbate multiple sclerosis symptoms. Patients should consult with their healthcare team about the use of alcohol or other recreational drugs in combination with their treatments.
There have been reports of patients experiencing sustained improvements in walking speed within two months of treatment with Ampyra. However, not all people will experience improvements with this treatment, so patients should ask their doctor what to expect in their specific situation.
There have been no reports of hair loss or weight gain as side effects of Ampyra in clinical trials. Patients who experience unexpected reactions after starting on a new medication are advised to seek guidance from their healthcare team.
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