Optical isomers of phenibut inhibit [H3]-Gabapentin binding in vitroand show activity in animal models of chronic pain

We report that R- and S-phenibut (β-phenyl-γ-aminobutyric acid) – derivatives of GABA – bind with an affinity of c.a.90μM to the gabapentin binding site in a competitive assay, a value comparable to that for previously claimed targets for this enantioermic molecule. This finding implied potential activity in neuropathic pain, this being one of the clinically validated indications for gabapentin.