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
Adverse 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
Mechanism 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