Levetiracetam has a novel mechanism of action that differs from all classic antiepileptics. It acts by:

• A Blocking HCN (Ih) channels, reducing pacemaker current
• B Selectively blocking AMPA receptors to reduce fast glutamatergic transmission
• C Inhibiting N-type voltage-gated calcium channels at presynaptic terminals
• D Binding to SV2A (synaptic vesicle glycoprotein 2A), modulating vesicular neurotransmitter release ✓

Explanation

Levetiracetam binds selectively to the SV2A protein on synaptic vesicle membranes; SV2A modulates vesicle docking, priming, and exocytosis. By altering SV2A function, levetiracetam reduces synchronised bursting and neurotransmitter release without affecting normal synaptic transmission. This completely novel mechanism explains its broad-spectrum efficacy and lack of pharmacokinetic interactions. Brivaracetam also acts on SV2A with higher affinity. HCN channels are targets of ivabradine (cardiac) and ZD7288 (experimental).

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.