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Mechanism of Action

mechanism of action video

Click below to watch a video presentation of AMPYRA's Mechanism of Action
(5:44/16.8 MB)

Launch Video

The First in a New Class of Approved MS Agents.

AMPYRA, a broad spectrum potassium channel blocker, has been shown in animal studies to increase conduction of action potentials in demyelinated axons through inhibition of potassium channels.5

The mechanism by which AMPYRA® (dalfampridine) Extended Release Tablets exerts its therapeutic effect has not been fully elucidated.5

loss of potassium can disrupt the nerve's ability to conduct messageswith ampyra potassium channels are blocked to enhance message conduction

  • As demonstrated in animal studies, AMPYRA blocks potassium channels, increasing conduction across demyelinated axons.5
  • Conduction failure and multiple sites of axonal degeneration are pathologic hallmarks of MS.10-12
  • AMPYRA did not prolong the QTc interval and did not have a clinically important effect on QRS duration.5

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Indication

AMPYRA® (dalfampridine) Extended Release Tablets is indicated as a treatment to improve walking in patients with multiple sclerosis (MS). This was demonstrated by an increase in walking speed.

IMPORTANT SAFETY INFORMATION

The use of AMPYRA is contraindicated in the following conditions: History of seizure, or moderate or severe renal impairment.

AMPYRA should not be taken with other forms of 4-aminopyridine (4-AP, fampridine), since the active ingredient is the same.

Patients should discontinue use of any product containing 4-aminopyridine prior to initiating treatment with AMPYRA in order to reduce the potential for dose-related adverse reactions, including seizures.

Seizures: AMPYRA can cause seizures. The risk of seizures increases with increasing AMPYRA doses. AMPYRA is contraindicated in patients with a prior history of seizure. Discontinue AMPYRA use if seizure occurs.

Renally impaired patients: AMPYRA is contraindicated in patients with moderate or severe renal impairment (CrCl ≤ 50 mL/min); the risk of seizures in patients with mild renal impairment (CrCl 51-80 mL/min) is unknown, but AMPYRA plasma levels in these patients may approach those seen at a dose of 15 mg twice daily, a dose that may be associated with an increased risk of seizures; estimated CrCl should be known before initiating treatment with AMPYRA.

Urinary tract infections were reported more frequently as adverse reactions in patients receiving AMPYRA 10 mg twice daily compared to placebo.

The most common adverse events (incidence ≥ 2% and at a rate greater than the placebo rate) for AMPYRA in MS patients were urinary tract infection, insomnia, dizziness, headache, nausea, asthenia, back pain, balance disorder, multiple sclerosis relapse, paresthesia, nasopharyngitis, constipation, dyspepsia, and pharyngolaryngeal pain.

The risk of adverse events, including seizures, increases with increasing AMPYRA doses. No additional benefit was demonstrated at doses greater than 10 mg twice daily.

There are no adequate and well-controlled studies of AMPYRA in pregnant women. AMPYRA should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Safety and effectiveness of AMPYRA in patients younger than 18 years of age have not been established.

Clinical studies of AMPYRA did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

For more information, please see the complete Prescribing Information, including the Medication Guide.

You are encouraged to report negative side effects of prescription drugs to the FDA.
Visit www.fda.gov/medwatch or call 1-800-FDA-1088.
You may also contact Acorda Therapeutics, Inc. at 1-800-367-5109.

AMPYRA® is a registered trademark of Acorda Therapeutics®, Inc.
AMPYRA® is marketed by Acorda Therapeutics®, Inc and manufactured under license from Alkermes Pharma Ireland Ltd.
© 2011 Acorda Therapeutics®, Inc. All rights reserved.

  is a registered trademark of Acorda Therapeutics®, Inc.

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