Baclofen for Muscle Spasticity: Treatment and Dosing
For muscle spasticity, start oral baclofen at 5 mg three times daily and titrate gradually to a typical maintenance dose of 30-80 mg/day divided into 3-4 doses, with non-pharmacological interventions as first-line therapy and intrathecal baclofen reserved for severe refractory cases. 1
Initial Treatment Approach
First-Line Non-Pharmacological Management
Before initiating baclofen, implement these interventions: 1
- Antispastic positioning
- Range of motion exercises
- Stretching programs
- Splinting
- Serial casting
When to Initiate Pharmacological Therapy
Consider baclofen when spasticity causes: 1
- Pain
- Poor skin hygiene
- Decreased function
- Impaired rehabilitation participation
Oral Baclofen Dosing Protocol
Starting Dose
Begin with 5 mg up to three times daily (15 mg/day total) to minimize side effects, particularly in older adults. 2
Titration Strategy
The titration approach differs based on spasticity origin:
For spinal-origin spasticity: 3
- Increase daily dose by 10-30% every 24 hours
- Assess response at least every 24 hours during titration
For cerebral-origin spasticity: 3
- Increase daily dose by 5-15% every 24 hours
- More conservative titration due to different response patterns
For pediatric patients: 3
- Increase by 5-15% every 24 hours regardless of spasticity origin
Target Maintenance Dose
- Typical effective range: 30-80 mg/day divided into 3-4 doses 1
- Older adults rarely tolerate doses exceeding 30-40 mg/day 2
- Some patients may require higher doses, though conventional maximum is 80 mg/day 4
Important Dosing Considerations
- Patients with complete spinal cord lesions (Frankel grade A) require significantly higher initial doses (approximately 156 mcg for intrathecal) compared to incomplete lesions (approximately 44 mcg) 5
- Renal impairment may lead to drug accumulation over time, requiring dose adjustment 4
Alternative Oral Agents for Generalized Spasticity
When baclofen is ineffective or not tolerated: 1, 6
- Tizanidine: Start 2 mg three times daily; generally better tolerated with less weakness than baclofen 2, 7
- Dantrolene: Acts directly on skeletal muscle; carries black box warning for hepatotoxicity (0.1-0.2% risk) 2
Focal Spasticity Management
Botulinum toxin is superior to oral baclofen for focal spasticity, particularly for: 1, 6
- Hand contractures post-stroke
- Ankle spasticity
- Any localized spasticity interfering with function
Use botulinum toxin as first-line pharmacological intervention for focal presentations, reserving oral baclofen as second-line. 1
Intrathecal Baclofen Therapy
Indications
Consider intrathecal baclofen for: 1, 6
- Severe spasticity unresponsive to maximum oral doses
- Generalized spasticity causing significant functional impairment
- Patients requiring only 10% of systemic dose for equivalent effect 1
Efficacy Data
Intrathecal baclofen demonstrates: 6, 7
80% of patients show improvement in muscle tone
65% of patients show improvement in spasms
Dosing Protocol
- Starting daily dose should be twice the effective bolus screening dose 3
- If prolonged response (>8 hours) or negative reactions occurred during screening, use the screening dose itself as starting dose 3
- Begin with 500 mcg/mL concentration 3
- Initiate pump fill and drug delivery intraoperatively with minimum 8-hour monitoring 3
Dosing Options
- Simple continuous dosing
- Variable 24-hour flex dosing
- Regularly scheduled boluses 3
Critical Safety Considerations
Monitoring Requirements
Monitor closely for: 2
- Muscle weakness
- Urinary function changes
- Cognitive effects
- Sedation
Withdrawal Risk
Never abruptly discontinue baclofen - withdrawal can cause: 2, 7
- Seizures
- Psychic symptoms
- Hyperthermia
- High fever
- Altered mental status
- Rebound spasticity
- Potentially death with intrathecal therapy 1
For intrathecal therapy, withdrawal typically evolves over 1-3 days and requires immediate resumption of infusion. 1 High-dose oral baclofen may not prevent acute withdrawal in patients previously on intrathecal therapy. 1
Oral Antispasmodic Weaning
When starting intrathecal baclofen, wean oral antispasmodics one drug at a time, beginning with oral baclofen. 3
Special Populations
- Renal disease: Limited data suggest unnecessarily high risk; use with extreme caution and monitor levels 7, 4
- Obstructive sleep apnea: Baclofen may worsen condition by promoting upper airway collapse 1, 6
- Brain damage/elderly: Higher risk of seizures and psychological disturbances 7
Contraindicated Medications
Avoid benzodiazepines (including diazepam) during stroke recovery due to deleterious effects on neurological recovery. 1, 2