July 24, 2012 — Ampyra (dalfampridine) is a multiple sclerosis drug that has been linked to an increased risk of seizures. The FDA has reviewed the post-marketing adverse event reports, and published a Drug Safety Communication because they found that these seizures are more likely soon after a patient starts Ampyra, usually within a few days or weeks.
Seizures were also more common in patients with moderate or severe kidney problems. The FDA is specifically warning patients not to take a double-dose when they accidentally miss a dose, because high doses could also increase the risk of seizure.
Ampyra (dalfampridine) has been approved by the U.S. Food and Drug Administration (FDA) as a treatment to improve walking in patients with multiple sclerosis (MS). It is manufactured and sold by Acorda Therapeutics, Inc. and received FDA approval in January 2010. Ampyra is also sold in Europe under the brand-name Fampyra.
Studies showed that Ampyra improved walking speed, as measured by a 25-foot walking test. Ampyra is contraindicated in patients who have a history of seizures or moderate/severe kidney impairment. The kidneys are responsible for eliminating Ampyra from the body, so patients with kidney impairment could develop dangerously excessive amounts of the drug. Many people with MS who are over 50 years old have impaired kidney function.
The label for Ampyra already warns about the potential risk of seizures. The FDA has issued the public safety update to warn that these seizures are most likely to occur in the first few days or weeks after starting the drug. Even people who have no history of seizures have had seizures while taking Ampyra.
The FDA has also issued recommendations to doctors whose patients are taking Ampyra. They should order periodic blood tests to check for signs of moderate or severe kidney impairment. Doctors should also specifically warn their patients not to double-up on doses if the patient accidentally misses a dose. The extra high amount of Ampyra could significantly increase the risk of seizure.
The FDA has also recently sent a warning letter the drug company responsible for Ampyra. The agency was specifically concerned about misleading statements in a promotional video. A woman was interviewed for a testimonial. Pictures were shown of her snowboarding, horseback riding, and she claimed Ampyra helped her walk across Home Depot without a cane. Ampyra is only indicated for increasing walking speed, as measured by a 25-foot walking test. The FDA said that the video “misleadingly suggests that treatment with Ampyra can have a positive impact on the disability caused by MS.” The agency also criticized the advertisements for minimizing the risk of serious side effects.