Which antiepileptic acts by inhibiting the neuronal and glial GABA transporter GAT-1, thereby prolonging the synaptic action of released GABA?

• A Gabapentin
• B Felbamate
• C Retigabine (ezogabine)
• D Tiagabine ✓

Explanation

Tiagabine is a nipecotic acid derivative that selectively inhibits the GAT-1 GABA uptake carrier, increasing extracellular GABA. Gabapentin binds the alpha2-delta subunit of voltage-gated calcium channels and has no direct GABA transport action. Retigabine opens KCNQ (Kv7) potassium channels. Felbamate acts at NMDA receptors and sodium channels. This transporter-based mechanism makes tiagabine unique among marketed antiepileptics.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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