Baclofen Dosage for Muscle Spasticity
The typical dosing range for oral baclofen is 30-80 mg/day, divided into 3-4 doses per day, as recommended by the American Heart Association for management of muscle spasticity. 1
Initial Dosing and Titration
- Start with low doses (5-10 mg/day) and titrate slowly to minimize side effects, particularly in older adults who rarely tolerate doses greater than 30-40 mg per day 1, 2
- Initial dosing should be 5 mg three times daily, with gradual increases to reach effective dose while monitoring for adverse effects 2
- Optimal therapy is the lowest effective dosage that provides symptomatic relief while minimizing side effects 3
Oral vs. Intrathecal Administration
- For severe spastic hypertonia that does not respond to oral medications, intrathecal baclofen therapy may be useful 4
- Intrathecal baclofen can be considered as early as 3-6 months after stroke for patients refractory to other treatments 4
- Only 10% of the systemic dose is required for equianalgesia via intrathecal route compared to oral administration 1
- Intrathecal baclofen has shown >80% improvement in muscle tone and >65% improvement in spasms in patients with severe spasticity 1
Treatment Algorithm for Spasticity Management
- First-line approaches include non-pharmacological interventions: antispastic positioning, range of motion exercises, stretching, splinting, and serial casting 1
- For generalized spasticity requiring pharmacological intervention, oral baclofen is a first-line option along with tizanidine or dantrolene 1, 2
- For focal spasticity, targeted injection of botulinum toxin is recommended to reduce spasticity, improve range of motion, and enhance function 4, 5
- For severe spasticity unresponsive to oral medications, intrathecal baclofen should be considered 4, 1
Important Precautions and Monitoring
- Patients on baclofen therapy should be closely monitored for muscle weakness, urinary function changes, cognitive effects, and sedation 2
- Abrupt discontinuation of baclofen should be avoided as it can cause central nervous system irritability and potentially severe withdrawal symptoms 2
- Some patients may experience paradoxical worsening of spasticity and pain with higher doses of baclofen, requiring dose reduction 6
- Baclofen blood levels may rise gradually over time in some patients on a stable dosing regimen, particularly in those with impaired renal function 7
Mechanism of Action
- Baclofen is a GABAB agonist that reduces spasticity by normalizing altered interneurone activity and decreasing alpha motoneurone activity 8
- It is most effective when spasticity has altered interneurone activity and increased motoneurone activity 8