Dalfampridine

Indications

Dalfampridine is used for: Multiple Sclerosis

Adult Dose

Multiple Sclerosis Indicated to improve walking in patients with multiple sclerosis by increasing walking speed 10 mg PO bid with or without food; take doses 12 hr apart Extended-release tablet; swallow tablet whole and do not chew, crush, divide, or dissolve tablets Hepatic impairment Not studied, but not expected to change dosing recommendations (primarily renal excretion)

Child Dose

<18 years: Safety and efficacy not established

Renal Dose

Renal impairment Moderate-to-severe (CrCl ?50 mL/min): Contraindicated due to increased risk of seizures Mild (CrCl 51-80 mL/min): Risk of seizure unknown, but plasma levels may be similar to levels of 15 mg PO bid, a dose that is possibly associated with increased seizure risk

Administration

Contra Indications

Hypersensitivity Moderate or severe renal impairment (CrCl ≤50 mL/min) History of seizure

Precautions

Discontinue if seizure occurs and do not restart; majority of seizures happened within days to weeks after starting the recommended dose and occurred in patients having no history of seizures Age-related decreases in renal function, and mild renal impairment is common after age 50 yr, even when serum creatinine is normal; renal function should be assessed by estimating creatinine clearance Do not take with other forms of 4-aminopyridine (4-AP, fampridine) to avoid adverse reaction due to the same active ingredient Estimate CrCl before initiating Do not double dose or take extra if dose missed Anaphylaxis and severe allergic reactions; signs and symptoms have included respiratory compromise, urticaria, and angioedema of the throat and or tongue; discontinue immediately and do not restart

Pregnancy-Lactation

Pregnancy Category: C Lactation: Unknown if excreted in breast milk; discontinue drug or breast feeding

Interactions

Side Effects

Side effects of Dalfampridine : >10% Urinary tract infection (12%) 1-10% Insomnia Dizziness Headache Nausea Asthenia Back pain Balance disorder Multiple sclerosis relapse Paresthesia Nasopharyngitis Constipation Dyspepsia Pharyngolaryngeal pain Dose-related increased risk of seizures

Mode of Action

Mechanism not completely understood, but in animal studies shown to block potassium channels, to delay repolarization and to increase duration of action potentials in demyelinated axons Does not prolong QTc interval