Retigabine (ezogabine) was the first antiepileptic designed around a novel molecular target. Its mechanism of action is:

• A Opening of KCNQ (Kv7) voltage-gated potassium channels ✓
• B Blockade of the GABA reuptake transporter GAT-1
• C Antagonism of the glycine site of the NMDA receptor
• D Irreversible inhibition of GABA transaminase

Explanation

Retigabine enhances the neuronal M-current by opening KCNQ2/KCNQ3 (Kv7) potassium channels, stabilising the resting membrane potential and reducing repetitive firing. It was withdrawn from many markets because of blue-grey skin discoloration and retinal pigment changes. GAT-1 blockade defines tiagabine, GABA transaminase inhibition defines vigabatrin, and glycine-site NMDA antagonism has no approved antiepileptic counterpart.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.