Vigabatrin

Vigabatrin (γ-Vinyl-GABA), an inhibitory neurotransmitter GABA vinyl-derivative, is an orally active and irreversible GABA transaminase inhibitor. Vigabatrin is an antiepileptic agent, which acts by increasing GABA levels in the brain by inhibiting the catabolism of GABA by GABA transaminase^[1][2][3]. In Vitro:Vigabatrin inhibits the uptake of taurine in Caco-2 and MDCK cells to 34% and 53%, respectively, at a concentration of 30 mM. In Caco-2 cells the uptake of Vigabatrin under neutral pH conditions is concentration-dependent and saturable with a Km-value of 27 mM. Vigabatrin is able to inhibit the uptake of taurine in intestinal and renal cell culture models^[2]. In Vivo:A significant increase in seizure threshold is observed following systemic (i.p.) administration of high (600 or 1200 mg/kg) doses of Vigabatrin. Bilateral microinjection of Vigabatrin (10 μg) into either the anterior or posterior substantia nigra pars reticulata (SNr) also increased seizure threshold, but less markedly than systemic treatment. Focal delivery into the subthalamic nucleus (STN) increased seizure threshold more markedly than either intranigral or systemic administration of Vigabatrin^[1].