FDA Updates Prescribing Info for Ampyra to Address Risk of Seizure in Those with Reduced Kidney Function
The U.S. Food and Drug Administration (FDA) released a Drug Safety Communication to address the risk of seizures in people with MS who are starting Ampyra® (dalfampridine, Acorda Therapeutics). Ampyra was approved in January 2010 to improve walking in people with MS. Seizures are a known side effect of Ampyra, and seizure risk increases with higher blood levels of the drug. Based on its evaluation of post-marketing reports of seizures occurring in people with MS on the therapy, the agency is updating prescribing information for Ampyra to advise that kidney function should be checked before starting Ampyra, and monitored at least annually, because impaired kidney function can result in high blood levels of the drug.
The FDA also emphasizes that patients who miss a dose should not take extra doses, since an extra dose of Ampyra can increase seizure risk. In its evaluation of adverse event reports, most of the seizures happened within days to weeks after starting the recommended dose and occurred in patients having no history of seizures. Most of those who experienced seizure were at least 50 years old and were at risk for mild, age-related kidney impairment.
The FDA communication notes that “The potential benefits of Ampyra treatment must therefore be carefully considered against the potential risk of seizures before using Ampyra in patients with mild renal impairment.”