Ampyra (dalfampridine): Drug Safety Communication - Seizure Risk for Multiple Sclerosis Patients

July 23, 2012

Audience: Neurology, Internal Medicine

ISSUE: FDA is updating health care professionals and the public about the risk of seizures in patients with multiple sclerosis (MS) who are starting Ampyra (dalfampridine). Using information received from post-market adverse event reports, FDA recently evaluated seizure risk in MS patients taking Ampyra (dalfampridine).  The majority of seizures happened within days to weeks after starting the recommended dose and occurred in patients having no history of seizures. The FDA is updating the Ampyra drug label to clarify recommendations.

BACKGROUND: Ampyra was approved to improve walking in patients with MS. Seizures are a known side effect of Ampyra, and seizure risk increases with higher blood levels of the drug.  Ampyra is eliminated from the body through the kidneys, and patients with kidney impairment may develop higher blood levels of the drug, thereby increasing their seizure risk. 

RECOMMENDATION: FDA reminds health care professionals that there are age-related decreases in renal function, and mild renal impairment is common after age 50, even when serum creatinine is normal.  Renal function should be assessed by estimating creatinine clearance. Ampyra should not be used in patients with a history of seizures or who have moderate to severe renal (kidney) impairment (measured as creatinine clearance [CrCl] less than or equal to 50 mL/min).

Additional information for Patients includes:

  • Tell your health care professional if you have kidney problems.
  • Your health care professional should order blood tests periodically to evaluate your kidney function.
  • Do not take Ampyra if you have ever had a seizure.
  • Ampyra tablets should be taken whole and not divided, crushed, chewed, or dissolved.
  • Do not take double or extra doses of Ampyra if a dose is missed.  Side effects, including seizures, are more frequent at higher doses.

Additional information for Health Care Professionals includes:

  • Ampyra is contraindicated in patients with a history of seizures or with moderate to severe renal impairment (CrCl < 50 mL/min).
  • The potential benefits of Ampyra treatment should be carefully considered against the risk of seizures before using Ampyra in patients with mild renal impairment (CrCl 51-80 mL/min).
  • A patient’s CrCl (calculated using the Cockroft-Gault equation) should be known before initiating Ampyra treatment and monitored at least annually whileAmpyra treatment continues, even when serum creatinine levels appear to be normal.
  • Tell patients they should not take double or extra doses of Ampyra if a dose is missed.  Adverse effects, including seizures, are more frequent at higherdoses.
  • Ampyra should be discontinued permanently if a seizure occurs.

Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA's MedWatch

Safety Information and Adverse Event Reporting Program:

  • Complete and submit the report Online: www.fda.gov/MedWatch/report.htm
  • Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to 1-
  • 800-FDA-0178

[07/23/2012 -Drug Safety Communication - FDA]

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