Prescribing-label excerpts
Baclofen
Reference for: Baclofen. Source presentation: solution. Source route: oral.
Mechanism of action
The precise mechanism of action of baclofen is not fully understood. Baclofen inhibits both monosynaptic and polysynaptic reflexes at the spinal level, possibly by decreasing excitatory neurotransmitter release from afferent terminals, although actions at supraspinal sites may also occur and contribute to its clinical effect. Baclofen is a structural analog of the inhibitory neurotransmitter gamma- aminobutyric acid (GABA), and may exert its effects by stimulation of the GABA Breceptor subtype.
Pharmacokinetics
A pharmacokinetic study in heathy adult male subjects under fasting conditions at 20 mg dose level demonstrated similar bioavailability for baclofen oral solution (5 mg/5 mL) and oral tablets. The peak plasma concentrations were achieved in about 0.75 hours from oral solution and the apparent elimination half-life is about 5.7 hours. Baclofen is excreted primarily by the kidney in unchanged form, and there is relatively large intersubject variation in absorption and/or elimination.
Selected passages from the cited U.S. prescribing label. The studies concern the source product and populations named in each passage; they do not establish Walter-product bioequivalence, an approved indication, or the kinetics of another fixed combination. Tables and the full prescribing information remain available in the source.
Source: DailyMed: Baclofen — solution
Reference accessed . Label revision: 2026-09-04.
