Retigabine (ezogabine), an antiepileptic later restricted by regulatory authorities, was the first agent to act by a mechanism unique among all antiepileptics. Its molecular target is:

• A Opening of KCNQ (Kv7) voltage-gated potassium channels ✓
• B Blockade of AMPA-type glutamate receptors
• C Enhancement of slow inactivation of sodium channels
• D Binding to the alpha-2-delta subunit of calcium channels

Explanation

Retigabine is a positive allosteric modulator that opens KCNQ (Kv7) potassium channels, particularly KCNQ2/3 heteromers underlying the M-current, thereby stabilising the resting membrane potential and reducing neuronal excitability. AMPA blockade defines perampanel, slow sodium channel inactivation defines lacosamide, and alpha-2-delta binding defines gabapentinoids. Retigabine was limited by blue-grey skin discolouration and retinal pigmentary changes.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.