EF-1502 is a potent and selective GABA transporter inhibitor with GAT1 and BGT1 inhibitory activity. EF-1502 produces a synergistic anti-epileptic effect when used in combination with Tiagabine , a compound used to suppress epileptic seizures. The dosing combination of EF-1502 exhibited reduced anti-epileptic efficacy and dyskinesia when used with THIP. The mechanism of EF-1502 differs significantly from Tiagabine , suggesting a unique role in the inhibitory strategy.