Peak plasma concentration ranges of CPM-acid achieved in human clinical studies (blue bar) and Beagle dog toxicology studies (red bar) superimposed on CPM-acid concentration response curves for inhibition of currents evoked by 1 mM γ-aminobutyric acid (GABA) or glycine and mediated by γ-aminobutyric acid type A (GABA_A) receptors or glycine receptors, respectively. Peak CPM-acid plasma concentrations were 100× higher in the Beagle dog studies than in the human clinical trials.