Lamotrigine hydrate inhibits Veratrine evoked release of glutamate and aspartate with ED 50 values of 21 μM for both amino acids, but Lamotrigine hydrate is less potent in the inhibition of GABA release (ED 50 =44 μM. At concentrations up to 300 μM, LTG has no effect on patassium-evoked amino acid [1]. Lamotrigine hydrate is some five times less potent in the inhibition of Veratrine-evoked [ 3 H]acetylcholine release (ED 50 =100 μM) than in glutamate or aspartate release [1].

Lamotrigine hydrate (IP, 30 min before pentylenetetrazol; 10 mg/kg, 15 mg/kg or 20 mg/kg) decreases the seizure intensity at the higher doses, it increases the latency to the first pentylenetetrazol-induced seizure in all studied doses compared with the controls [2].