Fampyra (Dalfampridine Extended-Release Tablets) is a potassium channel blocker. Its active ingredient, dalfampridine, can improve walking ability in adult patients with multiple sclerosis (MS), and clinical studies have shown that it can increase walking speed.

What Are the Side Effects of Fampyra (Dalfampridine Extended-Release Tablets)?

General Reactions

Urinary system: Urinary tract infections (12%).

Nervous system: Insomnia (9%), dizziness (7%), headache (7%), balance disorders (5%), paresthesia (4%).

Digestive system: Nausea (7%), constipation (3%), dyspepsia (2%).

Others: Back pain (5%), fatigue (7%), MS relapse (4%), nasopharyngitis (4%), sore throat (2%).

Adverse Reactions Leading to Discontinuation

Headache (0.5%), balance disorders (0.5%), dizziness (0.5%), confusional state (0.3%).

Severe Side Effects of Fampyra (Dalfampridine Extended-Release Tablets) Requiring Vigilance

Seizures

Most seizures occur within days to weeks after the start of treatment.

Management measures: A history of epilepsy must be ruled out before initiating medication.

Permanent discontinuation of the drug is required if a seizure occurs.

The risk is increased in patients with mild renal impairment.

Allergic Reactions

May present as dyspnea, urticaria, or angioedema of the larynx or tongue.

Management measures: If symptoms occur, discontinue the drug immediately and seek medical attention.

Renal-Related Risks

Contraindicated in patients with moderate to severe renal impairment (creatinine clearance [CrCl] ≤ 50 mL/min).

In patients with mild renal impairment (CrCl 51–80 mL/min), the blood drug concentration may approach the level associated with the 15mg dose, so a careful assessment of the risk-benefit ratio is necessary.

Precautions for Administering Fampyra (Dalfampridine Extended-Release Tablets)

Dosage Adjustments for Special Populations

Mild renal impairment: Use with caution.

Moderate to severe renal impairment: Contraindicated.

Elderly patients: Special attention should be paid to the assessment of renal function.

Administration Method

Swallow the tablets whole; do not break, crush, chew, or dissolve them.

If a dose is missed, do not make up for it; take the next dose at the originally scheduled time.

Contraindications

History of epilepsy.

Moderate to severe renal impairment (CrCl ≤ 50 mL/min).

Allergy to dalfampridine or 4-aminopyridine.

Monitoring During Treatment

Reassess renal function at least once a year.

Closely monitor for neurological symptoms.

Patient Education

Take the medication strictly as prescribed by the doctor; do not adjust the dosage independently.

Learn to recognize the early symptoms of seizures and allergic reactions.

Avoid driving or operating machinery if dizziness occurs.