Pivagabine [4-(2,2-dimethyl-1-oxopropylamino) butanoic acid] is a hydrophobic 4-aminobutyric acid derivative with neuromodulatory activity. Pharmacokinetic and toxicological evaluations showed that pivagabine penetrates the blood-brain barrier in rats, does not undergo metabolic transformation and exhibits a low toxicity after either single or repeated administration. Moreover, behavioral studies demonstrated that this compound prevented pentylenetetrazol- and bicuculline-induced convulsions in rats. Pivagabine was shown to improve performance on stress-related tests by reducing the anxiety-producing reactions to the various experimental settings. The marked antistress action of Pivagabine is mediated by antagonizing the effects of stress on GABA(A) receptor function and corticotropin-releasing factor concentrations in the brain, but not by altering the stress-induced increase in neurosteroid concentrations. Pivagabine treatment reduced the physical and mental fatigability of neurasthenia patients and increased their sense of well-being.