Part 5 - Antiseizure drugs Flashcards
What is a seizure?
A recurrent, uncontrolled cerebral excitation
Initiated by certain neurons
Cause of seizures?
Often unknown in younger people
Adult onset often secondary to specific event
Focal (Partial) Seizures
Simple seizures
Complex seizures
Generalized seizures
Absence seizures
Tonic-clonic seizures
Others
Types of seizures
Focal (Partial) Seizures
Generalized seizures
Unknown
Unknown seizures
Any seizure that doesn’t fit into the other classifications
Most common seizures
- Complex partial seizures
2. Generalized tonic-clonic
Antiseizure medication goal
Selective effect on hyperexcitable neurons
Primary antiseizure agents
Phenytoin (Dilantin) Carbamazepine (Tegretol) Ethosuximide (Zarontin) Valproates (Depakene) Others: Benzodiazapines, Barbiturates (Very effective)
Second generation antiseizure drugs
Gabapentin Lamotrigene Levetiracetam Pregabalin Tiagabine Topiramate
Benefits of 2nd generation antiseizure drugs
Tend to have milder side effects; more predictable profile
Allow more drug combinations for tx
Some are also used to tx neuropathic pain
Primary antiseizure mechanism
Dilantin, Tegretol, Depakene
-Decrease na+ entry into rapidly firing neurons
Zarontin
-Decreases ca++ entry into thalamic neurons
Several drugs increase GABA inhibition
Others decrease release or effects of excitatory amino acids
Antiseizure drugs minor side effects
Sedation Headache Dizziness Incoordination GI problems
Anti seizure drugs serious side effects
Liver toxicity Blood dyscrasias (problem with formation of blood cells) Increased risk of birth defects
Discontinuing anti seizure meds
60-70% can remain seizure free after medication stops
