Liquid chromatography-tandem mass spectrometry determination of baclofen in various biological samples and application to a pharmacokinetic study.

Baclofen is a structural analogue of γ-aminobutyric acid (GABA) that has been used for the treatment of spasticity since 1977. This study describes a simple and sensitive LC/MS/MS assay for the quantification of baclofen in rat plasma, urine, as well as various tissue samples. The assay utilized a simple protein precipitation and achieved lower limit of quantification (LLOQ) of 0.