Multiple sclerosis:

Indications for: AMPYRA

To improve walking in patients with multiple sclerosis (demonstrated by an increase in walking speed).

Clinical Trials:

The effectiveness of Ampyra in improving walking in patients with multiple sclerosis was evaluated in 2 adequate and well controlled trials involving 540 patients. Patients in these studies had a mean disease duration of 13 years and a mean Kurtzke Expanded Disability Status Scale (EDSS) score of 6.

Trial 1

  • Randomized, placebo-controlled, parallel group, 21-week study in 301 patients with multiple sclerosis.
  • A total of 283 patients (212 Ampyra and 71 placebo) completed all study visits.
  • Patient inclusion criteria included the ability to walk 25 feet in 8-45 seconds.
  • Exclusion criteria: History of seizures or evidence of epileptiform activity on a screening EEG, and onset of an MS exacerbation within 60 days.

Trial 2

  • Randomized, placebo-controlled, parallel group, 14-week study in 239 patients with MS.
  • A total of 227 patients (113 AMPYRA and 114 placebo) completed all study visits.
  • Same inclusion and exclusion criteria as in Trial 1.

Primary endpoint: Walking speed (in feet per second) as measured by the Timed 25-foot Walk (T25FW), using a responder analysis. A responder was defined as a patient who showed faster walking speed for at least 3 visits out of a possible 4 during the double-blind period than the maximum value achieved in the 5 non-double-blind no treatment visits.

Results: A significantly greater proportion of patients taking Ampyra 10mg twice daily were responders, compared with patients taking placebo (Trial 1: 34.8% vs 8.3%; Trial 2: 42.9% vs. 9.3%). Increased response rate was observed across all 4 major types of MS disease course. Compared with placebo, a significantly greater proportion of patients taking Ampyra had increases in walking speed of at least 10%, 20%, or 30% from baseline. The magnitude of improvement in walking ability was independent of concomitant drugs (63% of patients were using immunomodulatory drugs). No differences observed based on degree of impairment, age, gender, or BMI; the effect on race could not be evaluated.

Adult Dosage:

Swallow whole. ≥18yrs: max 10mg every 12hrs.

Children Dosage:

<18yrs: not established.

AMPYRA Contraindications:

History of seizures. Moderate or severe renal impairment (CrCl ≤50mL/min). Hypersensitivity to 4-aminopyridine.

AMPYRA Warnings/Precautions:

Assess renal function before initiation; monitor at least annually. Mild renal impairment (CrCl 51–80mL/min): increased risk of seizures. Discontinue if signs/symptoms of anaphylaxis occurs. Pregnancy. Nursing mothers.

AMPYRA Classification:

Potassium channel blocker.

AMPYRA Interactions:

Discontinue other forms of 4-aminopyridine prior to initiating. Concomitant OCT2 inhibitors (eg, cimetidine) may potentiate the risk of seizures.

Adverse Reactions:

UTI, insomnia, dizziness, headache, nausea, asthenia, back pain, balance disorder, MS relapse, paresthesia, nasopharyngitis, constipation, dyspepsia, throat pain; seizures (possible at higher doses), severe allergic reactions.


Two metabolites were identified: 3-hydroxy-4-aminopyridine (4.3%) and 3-hydroxy-4-aminopyridine sulfate (2.6%). These metabolites have been shown to have no pharmacologic activity on potassium channels. CYP2E1 was the major enzyme responsible for the 3-hydroxylation of dalfampridine.

Drug Elimination:

Dalfampridine and metabolites elimination is nearly complete after 24 hours, with 95.9% of the dose recovered in urine and 0.5% recovered in feces. Elimination half-life of dalfampridine is 5.2 to 6.5 hours.

Generic Drug Availability:


How Supplied: