The FDA is updating healthcare professionals about the risk of seizures in patients with multiple sclerosis (MS) who are starting Ampyra (dalfampridine; Acorda Therapeutics).

Using information received from post-market adverse event reports, the FDA recently evaluated seizure risk in MS patients taking Ampyra.  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.

The FDA reminds healthcare 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] ≤50mL/min).

Ampyra is a potassium channel blocker indicated to improve walking in patients with multiple sclerosis (demonstrated by an increase in walking speed).

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