← Search & browse all drugs
MUSCULO-SKELETAL SYSTEM › MUSCLE RELAXANTS › MUSCLE RELAXANTS, CENTRALLY ACTING AGENTS › Other centrally acting agents
baclofen
M03BX01
Forms & Strengths
- Oral Tablet: 10 mg, 20 mg
- Oral Solution: 5 mg/5 mL
- Intrathecal Solution: 0.05 mg/mL, 0.5 mg/mL, 2 mg/mL
Adult Dosing
- Oral: Start 5 mg TID, titrate by 5-15 mg/day every 3 days; max 80 mg/day (in 3-4 divided doses)
- Intrathecal (screening): 50 mcg via barbotage into lumbar space
- Intrathecal (maintenance): Continuous infusion, individual titration based on clinical response
Pediatric Dosing
- Oral (< 12 years): 0.4 to 0.8 mg/kg/day in divided doses TID to QID; start low (2.5 mg/dose) and titrate
- Oral (>= 12 years): Start 5 mg TID; titrate up to max 40-80 mg/day
- Intrathecal: Safety and efficacy not established in pediatric patients under 4 years
Indications
- Management of reversible spasticity resulting from multiple sclerosis
- Spinal cord lesions and other spinal cord injuries
- Intrathecal use: Severe chronic spasticity of spinal or cerebral origin
Mechanism of Action
- GABA-B receptor agonist at spinal cord level
- Inhibits both monosynaptic and polysynaptic reflexes
- Hyperpolarizes primary afferent fiber terminals, reducing excitatory neurotransmitter release
Contraindications
- Hypersensitivity to baclofen
- Abrupt cessation due to risk of severe withdrawal syndrome
Adverse Reactions
- Drowsiness, dizziness, and fatigue
- Hypotension and weakness
- Confusional state, headache, and insomnia
- Nausea, constipation, and urinary frequency
Drug Interactions
- CNS depressants (alcohol, opioids, sedatives): Enhanced sedation and respiratory depression
- Antihypertensives: Increased risk of hypotension
- MAO inhibitors: Increased CNS depression and hypotension
- Tricyclic antidepressants: May potentiate neuromuscular blockade and muscle weakness
Curated Content: Needs Vetting Before Put to Clinical Use