NCLEX Review Guide: Antiseizure Medications

Primary Antiseizure Drug Categories

• Phenytoin (Dilantin) - Stabilizes neuronal membranes by blocking sodium channels, preventing rapid firing of neurons that cause seizures.
• Carbamazepine (Tegretol) - Blocks sodium and calcium channels, effective for partial seizures and trigeminal neuralgia.
• Valproic Acid (Depakote) - Increases GABA availability and blocks sodium channels, broad-spectrum coverage for multiple seizure types.
• Levetiracetam (Keppra) - Modulates neurotransmitter release through synaptic vesicle protein binding, newer agent with fewer drug interactions.

Administration & Monitoring

1. Monitor therapeutic drug levels regularly (phenytoin: 10-20 mcg/mL, carbamazepine: 4-12 mcg/mL)
2. Assess for signs of toxicity: ataxia, diplopia, nystagmus, confusion
3. Evaluate seizure frequency, duration, and characteristics
4. Monitor for drug interactions, especially with warfarin, oral contraceptives

Essential Teaching Points

• Take medications exactly as prescribed - missing doses can trigger breakthrough seizures
• Avoid alcohol and other CNS depressants which can increase seizure risk and medication side effects
• Wear medical alert identification indicating seizure disorder and current medications
• Report signs of infection, unusual bleeding, or yellowing of skin/eyes immediately

Quick Knowledge Check

• ☐ I can identify the therapeutic range for phenytoin (10-20 mcg/mL)
• ☐ I understand why abrupt discontinuation is dangerous
• ☐ I can recognize signs of antiseizure medication toxicity
• ☐ I know which medications require regular blood monitoring
• ☐ I can teach patients about medication compliance importance