Clinical overview of the seizure risk of  dalfampridine.
BACKGROUND
Dalfampridine extended release tablets (dalfampridine-ER; known as prolonged-, modified or sustained-release fampridine in some countries) is a potassium channel blocker approved at 10 mg taken every 12 h, for the improvement of walking in patients with multiple sclerosis (MS). This has been demonstrated by an increase in walking speed. Its mechanism of action and narrow therapeutic range suggest the need to evaluate the seizure risk in treated MS patients.


METHODS
This paper discusses the seizure risk in clinical trials, and postmarketing experience of dalfampridine, relative to that in patients with MS. Electroencephalography as a predictive screening tool for seizure risk in dalfampridine-treated patients is also discussed.


CONCLUSIONS
The apparent seizure risk at the recommended dose of dalfampridine among patients with no prior seizure history may not be greater than the risk already present in the MS population. For MS patients, dalfampridine represents a promising new therapy for the improvement of walking impairment; its quick onset of action allows rapid determination of therapeutic response. The lack of prognostic value of electroencephalography for determining seizure risk suggests that treatment can be initiated without further screening when patients have no other contraindications. Strict adherence to the prescribed dosing regimen is essential.
Montefiore Medical Center, 111 East 210th Street, Bronx, NY 10467, USA. shaut@montefiore.org
Sheryl R
SR
Haut
E Jay
EJ
Bienen
Aaron
A
Miller
D015761:4-Aminopyridine / Q000009:adverse effects*; D004569:Electroencephalography / Q000187:drug effects; D006801:Humans; D009103:Multiple Sclerosis / Q000150:complications; D018579:Patient Selection; D026902:Potassium Channel Blockers / Q000009:adverse effects*; D011358:Product Surveillance, Postmarketing; D012640:Seizures / Q000139:chemically induced*
D026902:Potassium Channel Blockers; D015761:4-Aminopyridine