17.5 : 抗てんかん薬：カルシウムチャネル遮断薬

Calcium channel blockers, primarily known for cardiovascular use, have also shown potential as antiepileptic drugs. They exert their effects by modulating the flow of calcium ions within neurons.

In particular, these drugs target T-type calcium channels crucial for transmitting nerve signals. By blocking these channels, they reduce the release of glutamate and the influx of calcium ions into neurons. As a result, the rate of depolarization slows, diminishing seizure activity.

Common agents used in epilepsy management that inhibit calcium channels include ethosuximide, sodium valproate, and zonisamide.

Ethosuximide and sodium valproate are effective against absence seizures, while zonisamide treats focal seizures.

These drugs, when administered orally, are efficiently absorbed.

Although well tolerated, potential adverse effects may include gastrointestinal disturbances such as nausea and vomiting, and central nervous system effects such as drowsiness, tremors, and dizziness. Other side effects include skin rash, weight loss, and cognitive difficulties.