Ethosuximide

Summary

Ethosuximide is a drug used to treat absence seizures. It blocks T-type Ca2+ channels in the thalamus, inhibiting the propagation of action potentials that trigger and sustain rhythmic discharge in thalamic neurons. A rare side effect of Ethosuximide is Stevens Johnson Syndrome, which is a life-threatening skin condition characterized by skin burning and peeling. There’s also a few nonspecific side effects of ethosuximide, including dizziness, nausea, fatigue, and headaches.

Key Points

• Ethosuximide
  • Mechanism
    • Blocks thalamic T-type Ca2+ channels
      • Inhibits the propagation of APs that trigger and sustain rhythmical burst discharges in thalamic neurons
  • Clinical Use
    • Absence seizures (1st line)
  • Adverse Effects
    • Steven-Johnson Syndrome (SJS)
      • Drug-induced severe skin rash that may lead to skin necrosis
    • Fatigue, GI distress, headache, itching (and urticaria)