[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Multiple sclerosis disease-modifying therapies](https://durgical.com/en/pharmacology/classes/multiple-sclerosis-disease-modifying-therapies/) › Fampridine

# Fampridine

## Multiple sclerosis disease-modifying therapies?

Multiple sclerosis disease-modifying therapies

A potassium channel blocker that helps some people with multiple sclerosis walk better. It lowers the seizure threshold.

Updated Nov 1, 2026

Also called: Dalfampridine, 4-aminopyridine (4-AP)

## Quick facts

**Group**
[Multiple sclerosis disease-modifying therapies](https://durgical.com/en/pharmacology/classes/multiple-sclerosis-disease-modifying-therapies/)

**Target**
Voltage-gated potassium channels (Kv)

**Used for**
Improvement of walking in adults

**Key effects**
Insomnia · Nausea · Burning

**Monitor**
Kidney function before starting · Seizures

**ATC**
N07XX07

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

Fampridine (4-aminopyridine) blocks voltage-gated potassium channels in nerve fibres. With less potassium leaving the cell, repolarization slows and the action potential lasts longer, so nerve signals carry on more strongly along damaged nerves. In multiple sclerosis this improves walking in some patients; it does not change the course of the disease.

- Fampridine blocks K⁺ channels in nerve fibres
- Repolarization slows and action potentials lengthen
- Signals travel better along damaged nerves
- Walking improves in some people with MS

## Indications

- Improvement of walking in adults with multiple sclerosis [Multiple sclerosis →](https://durgical.com/en/conditions/multiple-sclerosis/)

## Adverse effects

### Common

- Insomnia, dizziness and headache
- Nausea, heartburn and constipation
- Burning, tingling or itching skin
- Balance problems and back pain

### Serious (rare, important)

- Seizures
- Urinary tract infection (painful or frequent urination, fever)
- Allergic reactions

## Contraindications

- History of seizures
- Kidney disease (the drug builds up)

## Key interactions

**Any other form of 4-aminopyridine (for example compounded by a pharmacy)**
Double exposure and a higher seizure risk

## What is monitored

- Kidney function before starting and over time
- Walking response after several weeks
- Seizures
- Heart rhythm in people with arrhythmia or long QT

## Administration and safety

- Extended-release tablet swallowed whole
- No more than two doses in 24 hours and no double doses: higher exposure raises the seizure risk
- It helps only while it is taken; the benefit may take 6 weeks or more

## Pregnancy and breastfeeding

There is little information in pregnancy; it is a decision for the treating team.

## Nursing care

- Ask about seizures and any abnormal EEG before starting
- Check kidney function
- Teach the signs of a urinary infection
- Assess walking and falls

## Pharmacokinetics

**Absorption**
Well absorbed by mouth

**Metabolism**
Mainly by acetylation

**Elimination**
By the kidneys; reduced kidney function raises its levels

## Memory aid

«4-AP = 4 Action Potentials longer»: blocks K⁺, the signal lasts, but seizures lurk.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the mechanism of fampridine?

It blocks voltage-gated potassium channels and prolongs nerve action potentials.

## What is fampridine used for in multiple sclerosis?

To improve walking; it does not modify the disease.

## Which two conditions contraindicate fampridine?

A history of seizures and kidney disease.

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[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 3

- [Fingolimod](https://durgical.com/en/pharmacology/fingolimod/)
- [Baclofen](https://durgical.com/en/pharmacology/baclofen/)
- [Tizanidine](https://durgical.com/en/pharmacology/tizanidine/)

## Related conditions 1

- [Multiple sclerosis](https://durgical.com/en/conditions/multiple-sclerosis/)

[← Back to the class: Multiple sclerosis disease-modifying therapies](https://durgical.com/en/pharmacology/classes/multiple-sclerosis-disease-modifying-therapies/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Dalfampridine: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a611005.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=N07XX07) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/fampridine/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/fampridine/