Drugs Reducing Neuronal Excitability (Channel Blockers)
To prevent neurons from generating pathological discharges, it is necessary to limit the influx of ions responsible for membrane depolarization. This is achieved using ion channel blockers.
Voltage-Gated Sodium Channel Blockers These agents directly reduce nerve cell membrane excitability by obstructing sodium ion currents. This group includes:
- Phenytoin
- Carbamazepine
- Lamotrigine
T-Type Calcium Channel Blockers This group selectively blocks low-threshold calcium channels located in neurons. The typical and sole representative listed in this classification is Ethosuximide.
Agents Enhancing GABAergic Inhibition
Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the CNS. Drugs in this broad category increase the efficacy of inhibitory processes to quench epileptic activity. The group is traditionally divided into three major subcategories:
- Barbiturates and their derivatives. Classic agents including Phenobarbital, Benzobarbital, and Primidone.
- Benzodiazepines. Widely known medications such as Diazepam, Clonazepam, and Lorazepam.
- Agents affecting GABA metabolism and uptake. These directly modulate neurotransmitter turnover. This includes Vigabatrin, Tiagabine, and Gabapentin.
Inhibition of Excitatory Amino Acids and Combined Action
In addition to GABA, the brain utilizes excitatory neurotransmitters—primarily glutamate and aspartate.
Excitatory Amino Acid Antagonists These medications block the effects of excitatory neurotransmitters, preventing the hyperactivation of neuronal networks. A prominent representative of this group is Felbamate.
Agents with a Combined Mechanism of Action Certain molecules are versatile enough to combine several of the pharmacological effects mentioned above (e.g., affecting both ion channels and GABA systems). Such complex agents include:
- Valproic acid
- Topiramate