A synthetic chlorophenyl-butanoic acid derivative used to treat spasms due to spinal cord damage and multiple sclerosis.
Muscle-relaxing baclofen acts as a gamma-aminobutyric acid (GABA) agonist specific for GABA-B receptors.
It acts at spinal and supraspinal sites, reducing excitatory transmission.
The topical preparation of baclofen, amitriptyline, and ketamine compounded in a penetration-enhancing polaxamer-lecithin organogel (PLO) has potential antineuralgic activity.
5 mg 3 times/day for 3 days, increased to 10 mg 3 times/day for 3 days. May further increase if needed. Max: 100 mg/day.
Test dose: 25 or 50 mcg. Increase dose by 25 mcg not more often than 24 hrly until 100 mcg/dose to determine appropriate dose. Responders w/ response lasting >8-12 hr, the test dose that was used to produce the response can be given as a 24-hr infusion; if the response lasted ≤8-12 hr, then a dose equivalent to twice the test dose is given. Adjust daily dosage as required. Maintenance: 12 mcg-2 mg/day for spasticity of spinal origin; 22 mcg-1.4 mg/day for spasticity of cerebral origin.
Adverse drug effects: Sedation, muscular hypotonia, nausea, urinary frequency, dysuria
Indications in palliative care: hiccups, painful muscle spasm, spasticity