BACLOFEN

• β-(4-chlorophenyl)-γ-Aminobutyric acid USDailyMed:Baclofen AU:B3 GABABreceptor agonistGABA-derivativeSkeletal muscle relaxantGABA analogueGabapentinoidSedativeAnxiolytic M03BX01(WHO) AU:S4(Prescription only)CA:℞-onlyNZ: Prescription onlyUK:POM(Prescription only)US:℞-only (RS)-4-Amino-3-(4-chlorophenyl)butanoic acid 1134-47-0 2284 1084 DB00181 2197 H789N3FKE8 D00241 CHEBI:2972 ChEMBL701 DTXSID5022641 Interactive image NCC(CC(=O)O)c1ccc(Cl)cc1 InChI=1S/C10H12ClNO2/c11-9-3-1-7(2-4-9)8(6-12)5-10(13)14/h1-4,8H,5-6,12H2,(H,13,14)Key:KPYSYYIEGFHWSV-UHFFFAOYSA-N Baclofen, sold under the brand nameLioresalamong others, is acentral nervous system(CNS)depressantandderivativeof the inhibitory neurotransmitter,γ-Aminobutyric acid(GABA).‍​‍‍‍​‍‍‍‍‍‍‍‍​‍ It is askeletal muscle relaxantmedicationused to treatmuscle spasms,muscle spasticity, such as from aspinal cord injuryormultiple sclerosis.Baclofen is a potentGABABreceptor agonist. It may also be used forhiccupsandmuscle spasmsnear the end of life,andoff-labelto treatalcohol use disorderoropioid withdrawalsymptoms.It is takenorallyor byintrathecal pump(delivered into the spinal canal via an implantable pump device). Baclofen should be avoided in the setting ofchronic kidney diseaseandend stage renal diseaseas even small doses can cause excessive toxicity.Common side effects include sleepiness, weakness, and dizziness.Serious side effects, such asseizuresandrhabdomyolysis, may occur if use of baclofen is stopped abruptly.Use duringpregnancyis of unclear safety, whilst use duringbreastfeedingis likely safe, and even more so if oral administration is avoided. The adverse effects and safety profile associated with baclofen when it is combined withsedative drugs(for examplealcohol,barbiturates, andbenzodiazepines) range depending on the dose and the individual. The interaction may increase the sedative effects of all ingested sedatives and as such is not generally recommended.In high doses the interaction can causede novoseizures. Baclofen was approved for medical use in the United States in 1977.It is available as ageneric medication.It is on theWorld Health Organization's List of Essential Medicines.In 2023, it was the 87th most commonly prescribed medication in the United States, with more than 7million prescriptions.