Fampridine

How it works

It is a potassium channel blocker that prolongs action potentials in demyelinated nerve fibres, improving conduction and neuromuscular transmission.

Prescribing in practice

• It lowers the seizure threshold and is contraindicated in patients with a history of seizures, so screen carefully before starting.
• It is renally excreted and contraindicated in renal impairment, so check renal function before and during treatment.
• Treatment should be assessed early and stopped if there is no demonstrable improvement in walking, as benefit occurs only in a proportion of patients.

Monitoring

Assess renal function before and periodically during treatment, and evaluate walking ability to confirm the drug is providing benefit.

Counselling the patient

• This medicine is intended to help your walking, and it will be stopped if it does not help you.
• Take the tablets without food and swallow them whole; do not crush or halve them.
• Tell us immediately if you have any seizure, blackout or unusual jerking.

Evidence & guidelines

Fampridine improves walking speed in a subset of people with multiple sclerosis in randomised controlled trials; response should be confirmed individually.