Dalfampridine Extended-Release Tablets (Fampyra) are a potassium channel blocker indicated to improve walking ability in adult patients with multiple sclerosis (MS).
Dosage and Administration of Dalfampridine Extended-Release Tablets (Fampyra)
Recommended Dosage and Administration Regimen
The maximum recommended dose of dalfampridine extended-release tablets is 10 mg twice daily, with doses separated by approximately 12 hours.
The total daily dose should not exceed 20 mg (equivalent to 2 tablets).
Clinical studies have shown that doses higher than this (e.g., 15 mg twice daily) do not provide additional therapeutic benefits; instead, they significantly increase the risk of adverse reactions (especially seizures) and the rate of treatment discontinuation.
Administration Method
This medication may be taken with or without food.
Tablets must be swallowed whole. Do not divide, crush, chew, or dissolve them.
Disruption of the extended-release structure will cause rapid drug release and a sharp rise in plasma drug concentration, which greatly increases the risk of seizures.
Missed Dose Management
If a dose is missed, do not take a make-up dose or double the next scheduled dose.
Patients should simply take the next dose at the regular time.
Pre-treatment and On-treatment Assessments
Estimated creatinine clearance (CrCl) must be assessed in patients before initiating dalfampridine treatment.
During treatment, renal function (CrCl) monitoring is recommended at least once a year.
This requirement is based on the fact that drug elimination is primarily dependent on the kidneys, and renal function status directly affects plasma drug concentration and treatment safety.
Dosage Adjustment of Dalfampridine Extended-Release Tablets (Fampyra)
Mild Renal Impairment (CrCl 51–80 mL/min)
In patients with this condition, plasma drug concentrations when taking the standard dose (10 mg twice daily) may approach the levels observed with 15 mg twice daily (i.e., 1.5 times the maximum recommended dose), which may increase the risk of seizures.
Before starting treatment, physicians must carefully weigh the potential benefits of medication against the risk of seizures.
No dosage adjustment is required, but enhanced monitoring and assessment are necessary.
Moderate to Severe Renal Impairment (CrCl ≤ 50 mL/min)
Dalfampridine extended-release tablets are contraindicated in patients with this condition.
Significant renal function decline will lead to drug accumulation in the body, causing a substantial increase in plasma drug concentration and a very high risk of severe adverse reactions.
As only the 10 mg tablet strength is currently available, lower doses cannot be administered. Therefore, this medication should not be used in such patients.
Use in Special Populations of Dalfampridine Extended-Release Tablets (Fampyra)
Geriatric Use
Geriatric patients are more likely to have concomitant renal function decline.
Renal function status must be fully considered during medication use to avoid the risk of drug accumulation.
Pregnancy
Sufficient data on the use of dalfampridine in pregnant women are currently lacking.
Use during pregnancy may be considered only if the potential benefit justifies the potential risk to the fetus.
Use in Patients with Hepatic Impairment
Dalfampridine is primarily excreted unchanged via the kidneys, and hepatic metabolism is not the main elimination pathway.
Hepatic impairment is not expected to significantly affect its pharmacokinetics, so dosage adjustment is generally not required.
However, clinical medication use should still be comprehensively determined based on the patient’s overall condition.
