Calcium Channel Modifying Agents

Anticonvulsants

Ethosuximide

First-line for absence seizures

Ethosuximide is preferred over valproate for school-age children because it has fewer side effects.

• Inhibition of voltage-gated calcium channels (T-type) in neurons of the thalamus

• Gastrointestinal symptoms

• Allergic skin reactions (urticaria, Stevens-Johnson syndrome)

• Pancytopenia

• Fatigue

• Headache

• Myopia

To remember that the most important side effects of ethoSUXimide are Steven-Johnson syndrome, fatigue, headache, ABdominal upset, and ALLErGies (e.g., urticaria), think of “It sucks that Steven's FATher has given everyone a headache with his ABsurd ALLEGorizations.”

• Pregnancy (especially valproate and carbamazepine)

• Increases serum levels of phenytoin