Drugs

FDA Drug Safety Podcast for Healthcare Professionals: Seizure risk for multiple sclerosis patients who take Ampyra (dalfampridine)

Narrator: Welcome to the FDA Drug Safety Podcast for Healthcare Professionals from the Division of Drug Information. Today’s topic: Seizure risk for multiple sclerosis patients who take Ampyra (or dalfampridine).

Lesley Navin, a Nurse Practitioner in the Division, will provide you with additional information about this Communication.

Guest Speaker: On July 23rd, 2012, the Food and Drug Administration issued a Drug Safety Communication updating health care professionals and the public about the risk of seizures in patients with multiple sclerosis (or 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. The majority of seizures happened within days to weeks after starting the recommended dose and occurred in patients having no history of seizures.

In addition, FDA is updating the Ampyra drug label to clarify recommendations that kidney function should be checked in patients before starting Ampyra and monitored at least annually while Ampyra treatment continues. Additionally, patients who miss a dose should not take extra doses—an extra dose of Ampyra can increase seizure risk.

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. Ampyra should not be used in patients with a history of seizures or who have moderate to severe renal (or kidney) impairment (measured as creatinine clearance less than or equal to 50 mL/min).

In patients with mild renal impairment (measured as creatinine clearance 51-80 mL/min), the blood levels of Ampyra may reach levels associated with increased seizure risk. Therefore for patients with mild renal impairment, the use of Ampyra requires careful consideration of the potential benefits of treatment as well as the potential risk of seizure.

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.

At this time FDA recommends that Healthcare Professionals be aware that:

Ampyra is contraindicated in patients with a history of seizures or with moderate to severe renal impairment (measured as creatinine clearance less than or equal to 50 mL/min).
Mild renal impairment is common after age 50.
The potential benefits of Ampyra treatment should be carefully considered against the risk of seizures before using Ampyra in patients with mild renal impairment (measured as creatinine clearance 51-80 mL/min).
Most of the seizures reported with Ampyra treatment occurred in patients without a history of seizures.
A patient’s CrCl (calculated using the Cockroft-Gault equation) should be known before initiating Ampyra treatment and monitored at least annually while Ampyra treatment continues, even when serum creatinine levels appear to be normal.
The maximum recommended dose of Ampyra is 10 mg twice daily (taken 12 hours apart). Ampyra tablets should be taken whole and not divided, crushed, chewed, or dissolved.
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 higher doses.
Ampyra should be discontinued permanently if a seizure occurs.
Adverse events involving Ampyra should be reported to the FDA MedWatch program at www.fda.gov/medwatch.

Narrator: Thank you for listening. The FDA is committed to keeping healthcare professionals informed of the latest safety information. A link to this communication as well as the complete Data Summary can be found at www.fda.gov/DrugSafetyCommunications. If you have drug questions, you can reach us at druginfo@fda.hhs.gov.