Baclofen is a GABA-B (γ-aminobutyric acid type B) receptor agonist primarily used to treat muscle spasticity. It has significant applications in neurological disorders including multiple sclerosis, spinal cord injury, stroke, and amyotrophic lateral sclerosis[1][2].
Baclofen is a selective GABA-B receptor agonist:
Presynaptic inhibition:
Postsynaptic inhibition:
Interneuron modulation:
| Condition | Use |
|---|---|
| Multiple sclerosis | Lower limb spasticity |
| Spinal cord injury | Spasticity management |
| Stroke | Post-stroke spasticity |
| ALS | Spasticity, muscle cramps |
| Cerebral palsy | Generalized spasticity |
| Traumatic brain injury | Spasticity management |
| Parameter | Value |
|---|---|
| Starting dose | 5 mg 3 times daily |
| Titration | Increase by 5-15 mg every 3 days |
| Maximum | 80-100 mg/day |
| Frequency | 3-4 times daily |
Important: Abrupt withdrawal can cause:
Taper slowly over 2+ weeks[5]
| Property | Oral | Intrathecal |
|---|---|---|
| Bioavailability | 70-80% | Direct CNS |
| Onset | 1-2 hours | Minutes to hours |
| Peak | 2-3 hours | Variable |
| Half-life | 2-4 hours | 4-6 hours |
| Excretion | Renal (70-80%) | CSF absorption |
| Protein binding | 30% | Minimal |
| Drug Class | Interaction |
|---|---|
| CNS depressants | Enhanced sedation |
| Antihypertensives | Additive hypotension |
| Lithium | Potential toxicity |
| Anticonvulsants | May require dose adjustment |
| Tricyclic antidepressants | Enhanced sedation |
| Drug | Mechanism | Route | Key Feature |
|---|---|---|---|
| Baclofen | GABA-B agonist | Oral, IT | First-line |
| Tizanidine | α2-adrenergic | Oral | Less weakness |
| Diazepam | GABA-A | Oral, IV | Anxiety component |
| Dantrolene | Direct muscle | Oral | Hepatotoxicity risk |
| Phenol | Chemical neurolysis | Injection | Permanent |
Lubsen J et al. Baclofen for spasticity (2011). 2011. ↩︎
Nardone R et al. Baclofen in neurological disorders (2022). 2022. ↩︎
Bowery NG et al. GABA-B receptor pharmacology (2010). 2010. ↩︎
Zhu H et al. Baclofen in ALS (2020). 2020. ↩︎