Tiagabine may induce seizures in those without epilepsy, particularly if they are taking another drug which lowers the seizure threshold. There may be an increased risk of psychosis with tiagabine treatment, although data is mixed and inconclusive. Tiagabine can also reportedly interfere with visual color perception. Warning
CNS depression
Dermatologic reactions
Generalized weakness
Ophthalmic effects
Suicidal ideation

Overdose
Tiagabine overdose can produce neurological symptoms such as lethargy, single or multiple seizures, status epilepticus, coma, confusion, agitation, tremors, dizziness, dystonias/abnormal posturing, and hallucinations, as well as respiratory depression, tachycardia, hypertension, and hypotension. Overdose may be fatal especially if the victim presents with severe respiratory depression and/or unresponsiveness. Pharmacology
Tiagabine increases the level of γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, by blocking the GABA transporter 1 (GAT-1), and hence is classified as a GABA reuptake inhibitor (GRI). Pharmacodynamics
Tiagabine is primarily used as an anticonvulsant in the treatment of epilepsy as a supplement. Although the exact mechanism by which Tiagabine exerts its antiseizure effect is unknown, it is thought to be related to its ability to increase the activity of gamma aminobutyric acid (GABA), the central nervous systems major inhibitory neurotransmitter. Tiagabine attaches to the GABA uptake carriers recognition sites. Tiagabine is thought to block GABA uptake into presynaptic neurons as a result of this action, allowing more GABA to be available for receptor binding on the surfaces of post-synaptic cells.
Monitoring Parameters
Seizure frequency, liver function tests , suicidality

History
Tiagabine was discovered at Novo Nordisk in Denmark in 1988 by a team of medicinal chemists and pharmacologists under the general direction of Claus Bræstrup. The drug was co-developed with Abbott Laboratories, in a 40/60 cost sharing deal, with Abbott paying a premium for licensing the IP from the Danish company.U.S. patents on tiagabine listed in the Orange Book expired in April 2016. See also
CI-966
Deramciclane
Nipecotic acid
SKF-89976A

References
External links
Gabitril(manufacturers website)