A muscle relaxant for spasticity
Baclofen
A muscle relaxant that eases muscle stiffness and spasms in conditions such as multiple sclerosis and spinal-cord injury.
What is Baclofen?
Baclofen is a muscle relaxant used to relieve spasticity — the tight, stiff and sometimes painful muscle spasms seen in conditions such as multiple sclerosis and spinal cord problems. It works on the nervous system to reduce excessive muscle tone.
Education and reference only. This is a plain-language guide to Baclofen — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Baclofen is a muscle relaxant used to relieve spasticity — the tight, stiff, sometimes painful muscle spasms that come with conditions affecting the brain and spinal cord, such as multiple sclerosis (MS) and spinal-cord injury. The familiar brand is Lioresal, though most prescriptions are for the generic. It is usually taken as a tablet, built up slowly to the level that loosens the muscles enough to help movement, comfort and care without causing too much weakness or drowsiness. In selected people with severe spasticity it can be delivered directly around the spinal cord through an implanted pump.
How it works
Baclofen acts on the spinal cord, where it calms the nerve signals that drive muscles into spasm. It mimics a natural calming chemical (GABA) at a particular receptor, which dampens the over-active reflexes responsible for stiffness and spasm. The result is looser, less rigid muscles — but because it works on the nervous system more broadly, it can also cause drowsiness and a feeling of weakness.
Company & origin
Originated / developed by: Ciba (now Novartis).
Baclofen was synthesized in 1962 by Heinrich Keberle at Ciba in Basel, Switzerland, as a lipophilic GABA analogue, and was marketed as the muscle relaxant Lioresal in 1972.
Practical use
How to take Baclofen
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is usually started at a low intensity and increased gradually to find the level that helps without too much drowsiness.
- Take it regularly as prescribed; do not change the schedule on your own.
- Never stop it suddenly — abrupt withdrawal can cause serious effects such as confusion, hallucinations, worsening spasticity and seizures, so any reduction must be gradual and supervised.
- It can cause drowsiness and muscle weakness, so take care with driving or operating machinery until you know how it affects you.
- Avoid alcohol, which adds to the drowsiness.
- Tell your doctor about kidney problems, as the medicine may need adjusting.
Weighing it up
Advantages & disadvantages of Baclofen
Advantages
- Effectively reduces painful muscle stiffness and spasms.
- Can improve mobility, comfort and sleep in spasticity.
- Long experience of use in neurological conditions.
- Dose can be tailored to balance benefit and side effects.
Disadvantages
- Commonly causes drowsiness, dizziness and muscle weakness.
- Must never be stopped abruptly because of a risk of serious withdrawal effects.
- Can lower blood pressure and worsen confusion in some people.
- May need dose adjustment in kidney impairment.
Practical use
Good to know
It is started low and increased gradually to find the level that helps without making muscles too weak or causing too much drowsiness; the aim is useful relief, not complete loss of all tone. It can make you sleepy and slow your reactions, so take care with driving and machinery until you know how it affects you, and it adds to the effect of alcohol and other sedating medicines. Crucially, it must never be stopped suddenly after regular use — abrupt withdrawal can cause serious effects such as confusion, hallucinations, a return of severe spasms, and very rarely seizures — so it is always tapered down.
Who should not take it / use with caution
- Stopping suddenly is dangerous — it must be reduced gradually under guidance, never stopped abruptly after regular use.
- Used with caution in people with epilepsy, a history of stomach ulcers, significant kidney problems, certain breathing or mental-health conditions, and in older people.
- Care is needed in people who rely on a degree of muscle stiffness to stand or transfer, as reducing it too much can affect their mobility.
Monitoring
- Response of spasticity and overall function
- Drowsiness and muscle weakness so the level can be fine-tuned
- Kidney function where relevant; careful review before any dose reduction or stopping
Side effects
- Drowsiness, tiredness and a feeling of weakness, especially when starting or increasing.
- Dizziness, nausea, dry mouth, or confusion.
- Less commonly, low mood, difficulty passing urine, or muscles becoming too floppy; report this so the level can be adjusted.
Key interactions
- Adds to the drowsiness of alcohol, sleeping tablets, strong painkillers, and other sedating medicines.
- Blood-pressure-lowering medicines can have an added effect, increasing dizziness.
- Care alongside other medicines that affect the nervous system or kidney function.
Available as: Tablets, and a liquid for those who cannot swallow tablets. A specialist form is given directly around the spinal cord through an implanted pump in selected cases.
Answers
Baclofen: frequently asked questions
Can I stop baclofen suddenly if I feel better?
No — stopping baclofen abruptly after taking it regularly can cause serious withdrawal effects, including confusion, hallucinations, a rebound of severe spasms and, rarely, seizures. If you want to stop, your prescriber will reduce it gradually over time. Never stop it on your own.
Will baclofen make me too weak to move?
It is started low and built up to find the level that loosens stiff muscles without making them too weak. Some people rely on a degree of stiffness to stand or transfer, so the aim is balance, not total loss of tone. Tell your prescriber if you feel too floppy or too weak so the level can be adjusted.
Can I drink alcohol while taking baclofen?
Alcohol adds to baclofen's drowsiness and can make you very sleepy or unsteady, increasing the risk of falls. It is best avoided or kept to a minimum, especially when you are starting or increasing the dose.
Is it safe to drive on baclofen?
Baclofen can cause drowsiness and slow your reactions, particularly early on. Do not drive or use machinery until you know how it affects you, and avoid it altogether if you feel sleepy or dizzy. Combining it with alcohol or other sedating medicines makes this worse.
What is the difference between baclofen and Lioresal?
They are the same medicine — baclofen is the generic (active-ingredient) name and Lioresal is a brand name. Generic baclofen contains the identical active ingredient.
The wider class
About Muscle relaxants
Baclofen belongs to the muscle relaxants class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
Browse by body system
Authoritative sources
- BNF: Baclofen.
- electronic Medicines Compendium (SmPC): Baclofen (Lioresal).
- NICE CKS: Baclofen.
Building a medicines information resource?
We create evidence-led, dose-free drug and formulary references for teams.