Master Ethosuximide: Mechanism of Action

Ethosuxamide is used as a first line agent to treat absence seizures (petit mal seizures), and is preferred over other agents because this drug does not cause hepatotoxicity.

This medication binds and blocks thalamic T-type Ca²⁺ channels. T-type channels serve pacemaking functions in both central neurons and support calcium signaling, and are also involved in the modulation of firing patterns of neurons.

Ethosuxamide can trigger Stevens-Johnson syndrome. Stevens-Johnson syndrome is a life threatening skin condition, which is a hypersensitivity complex affecting the skin and mucous membranes.

Patients taking ethosuximide can complain of fatigue, as this is a common side effect.

Patients taking this drug often have the side effect of diarrhea and GI upset. Constipation can also occur.