baclofen at a glance
Medicine class
Centrally acting antispastic muscle relaxant
Available routes
Tablets, oral liquids and specialist intrathecal administration
Stopping treatment
Must not usually be stopped suddenly because serious withdrawal can occur
What is baclofen used for?
Licensed products cover symptomatic treatment of spasticity arising from neurological disease or injury.
Oral baclofen treats spasticity of cerebral origin, including that associated with cerebral palsy, stroke, meningitis or traumatic brain injury.
It also treats spasms and spasticity from spinal cord disorders, including multiple sclerosis, motor neurone disease, transverse myelitis, syringomyelia, trauma and spinal cord compression.
Intrathecal baclofen is reserved for severe chronic cerebral or spinal spasticity when oral treatment has not worked adequately or caused unacceptable adverse effects.
How does baclofen work?
Baclofen activates inhibitory GABA-B receptors, mainly within the spinal cord. This reduces excitatory signalling through spinal reflex pathways, helping lessen excessive muscle activity, spasms and clonus.
baclofen preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 0.5 mg/mL, 2 mg/mL
Oral solution
Route: Oral
Strengths: 5 mg/5 mL, 10 mg/5 mL
How to take baclofen
Follow the product label and prescriber's instructions. Take oral baclofen with or after food if advised or if nausea occurs. Measure liquid with the supplied oral syringe or medicine spoon, not a kitchen teaspoon. Intrathecal baclofen is administered and managed only by an experienced specialist team.
Swallow tablets with liquid.
Handle oral liquid as directed by its label and use the supplied measuring device.
Do not stop oral or intrathecal baclofen without clinical supervision.
Attend all planned intrathecal pump refill and review appointments.
baclofen side effects
Common or expected effects
- Sleepiness, tiredness, dizziness or weakness
- Nausea or vomiting
- Headache or dry mouth
- Blurred vision or difficulty focusing
- Sleep disturbance
- Diarrhoea or constipation
- Reduced muscle tone
Get urgent medical advice
- Severe allergic reaction, including facial or throat swelling and breathing difficulty
- Marked drowsiness, reduced consciousness or slow or difficult breathing
- Seizures or severe confusion
- Rapidly worsening spasticity, high temperature or rigidity after interruption or withdrawal
- Yellow skin or eyes, which may indicate liver injury
- New or worsening suicidal thoughts
baclofen in pregnancy
Baclofen is not routinely recommended during pregnancy, but it may be continued when controlling severe spasticity is important and expected benefit outweighs uncertainty about fetal risk. Do not stop it suddenly. Oral exposure near delivery can cause neonatal withdrawal, so maternity and neonatal teams may need advance notice and post-birth monitoring.
baclofen while breastfeeding
Baclofen passes into breast milk in small amounts, and breastfeeding may be possible when the infant is healthy. Seek advice if the baby feeds poorly, becomes unusually sleepy, or develops a dry mouth, rash, vomiting or diarrhoea.
baclofen interactions
Review all prescribed, non-prescription and recreational substances because baclofen can add to sedation, weakness, low blood pressure or toxicity.
Alcohol, opioids and other CNS depressants
Sedation and respiratory depression may increase; alcohol can also make baclofen's effects unpredictable.
Other muscle relaxants, including tizanidine
Sleepiness, weakness and reduced muscle tone may increase.
Common questions about baclofen
Answers are fully visible for fast scanning and source review.
Can baclofen be stopped suddenly?
Usually not. Abrupt withdrawal can cause worsening spasms, confusion, hallucinations, high temperature or seizures; interruption of intrathecal treatment can be life-threatening.
Can baclofen make me sleepy?
Yes. Sleepiness, dizziness and tiredness are common, particularly when treatment changes or baclofen is combined with other sedating substances.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.