Chapter 15 - Drugs for Seizures

Question 1

Phenobarbitol Class: Barbiturates

Answer 1

Action:
Change the action of GABA, which is the primary neurotransmitter in the brain, by
stimulating the influx of chloride ions. This suppresses the firing ability of neurons.

Uses:
Control seizures

Contraindications:
Pregnancy, allergy to barbiturates, pre-existing CNS depression, server respiratory disease
with dyspnea or obstruction, glaucoma or prostatic hypertrophy

Adverse Effects:
Dependence, drowsiness, vitamin deficiencies, and laryngospasm

Patient Teaching:
- Watch the insertion site

Pregnancy Category: D

Question 2

Diazepam Class: Benzodiazepine

Answer 2

Action:
Similar to that of barbiturates but safer

Uses:
Short-term seizure control with absence and myoclonic seizures. IV administration is
used to terminate status epilepticus.

Contraindications:
Pregnancy, allergy to benzodiazepines, closed-angle glaucoma, coma, myasthenia
gravis, ethanol intoxication, hepatic disease, sleep apnea

Adverse Effects:
Drowsiness and dizziness.

Patient Teaching:

• Rise slowly; fainting may occur
• Avoid hazardous activities
• Avoid alcohol and other CNS depressants

Pregnancy Category:D

Question 3

Phenytoin Class: Hydantoin

Answer 3

Action:
Desensitize sodium channel

Uses:
Treating all types of epilepsy except absence seizures.

Contraindications:
Pregnancy, allergy, psychiatric condition, bradycardia, SA and AV block, StrokesAdams
syndrome

Adverse Effects:
CNS depression with excessive dosages, gingival hyperplasia (which occurs in about
20% of patients), skin rash, cardiac dysrhythmias, and hypotension

Patient Teaching:
- Serum levels will need to be monitored (>2, >10-20 is toxic levels)
- > 40 severe lethargy, >50 coma
- Notify physician if you have swollen gums, yellowing skin or eyes, fever, bleeding,
or rash
- Can change blood sugar levels for diabetics
- Take at the same time everyday to ensure effectiveness
- Gingival hyperplasia in 50% of patients with long term therapy ***

Administer slowly to avoid skin irritation, flush the line with normal saline before and after to avoid
mixing with other medications. When mixed with dextrose can cause crystal formation, use only
normal saline and use filter when administering (IV) Large vein to avoid purple glove syndrome

Pregnancy Category: D

Question 4

Valproic Acid Class: Anticonvulsant

Answer 4

Action:
Desensitize sodium channels

Uses:
Absence seizures. Used in combination for other seizure disorders

Contraindications:
Allergy, urea cycle disorders

Adverse Effects:
Limited CNS depression, visual disturbances, ataxia, vertigo, and headache.
Additional adverse reactions include gastrointestinal effects, hepatotoxicity, and
pancreatitis.

Patient Teaching:

• Physical dependence may result from long term use
• Drink plenty of fluids
• Avoid hazardous activities
• Do not take with carbonated drinks, will react with acid
• Hepatic tests to check for hepatic toxicity
• Less sedation

Black Box Warning: pregnancy, hepatic disease, pancreatitis, children under the age of 2

Pregnancy Category: D

Question 5

Ethosuximide Class: Succinimides

Answer 5

Action:
Suppress calcium influx; it works by delaying calcium influx into neurons, which
raises the seizure threshold and thereby suppresses the seizure

Uses:
Absence seizures. Also used as a combination drug

Contraindications:
Liver or kidney disease, children younger then the age of 3, allergy to this
medication

Adverse Effects:
Adverse effects are rare, but drowsiness, dizziness, and lethargy may occur initially.
Administering with food can reduce nausea and vomiting.
Very rare but serious side effects include systemic lupus erythematous, leukopenia,
aplastic anemia, and Stevens-Johnson syndrome.

Patient Teaching:

• Suicidal ideation can occur within one week of starting therapy
• Watch for panic attacks, violent behavior and anxiety
• Overdose symptoms: stupor and ataxia (CNS)

Pregnancy Category: C