Card Set Information

2012-06-25 16:05:13
PT3 Antiepilepsy drugs

Antiepilepsy Drugs
Show Answers:

  1. What is epilepsy?
    • Recurrent seizures characterized by excessive electrical discharge of nerves in the cerebral cortex
    • It is a set of symptoms, rather than a disease entity

    • Characterized by:
    • Abnormal EEG
    • Abnormal motor function
    • Loss of consciousness
    • Interference with sensory function
    • Psychic changes

    May have to give up drying, may have personality changes or inapproprate outbursts of crying or laughter.
  2. How seizures begin
    • Idiopathic
    • Approximately 75%--Cause unknown, but genetics plays a role
  3. How Seiures Begin
    • Acquired
    • Increased intracranial pressure (ICP)
    • CNS infection
    • -Meningitis
    • -Encephalitis
    • Metabolic Disorders
    • -Hypoglycemia: Low BS often triggers seizures in people who are prone to them.
    • Vascular accidents
    • -Thrombosis. Phlebitis can trigger seizure in those prone to them.
    • Fever, esp children. Fevers can be a trigger. If child has one, he'll probably have more, but does not necessarily mean fever will trigger seizure later in life (older than 5)
    • Chemical toxicity --CO
    • Aneurysms
    • Tumors
    • Head trauma
    • Drug therapy W/D from barbiturates or alcohol
    • Severe hypoxia: In pts who become confused while we're seeing them, think hypoxic and get on O2 and see what happens.
    • Overdose of illicit drugs
  4. Classification of seizures
    • Generalized:
    • Widespread abnormal electrical discharge across the entire cortex. If a partial seizure spreads to the opposite hemisphere, it becomes a secondary generalized seizure
    • Tonic contraction-Total stiffness of the body, back will arch.
    • Clonic: contractions of all muscles including diaphram, raspy intermittent breaths.

    • Partial:
    • Involves an abnormal electrical discharge in only one hemisphere of the brain.
    • Petit mal seizures. Brief laps of the brain. May be up to 100/day.
  5. Phases
    • Preictal
    • Tonic
    • Clonic-muscle contraction and relaxation. What people typically think when visualizing a seizure.
    • Postictal-after the seizure
  6. Status Epilepticus
    • Two or more consecutive seizures without the patient regaining consciousness inbetween
    • Continuous seizure activity lasting 5 minutes or more
    • Medical Emergency, because pt will become hypoxic.
  7. Treatment for Epilepsy
    • Antiepileptic Drugs -- AED’s
    • Surgery—Resection of affected area or cutting through nerve pathways
    • Vagal Nerve Stimulation –Implantation of a vagal nerve stimulator
    • **Client should wear a medic alert tag if pt is prone to seizure**
  8. AEDs General info
    Mechanism of Action: Suppress activity of damaged neurons to minimize electrical discharge thus stabilizing the flow of substances in and out of brain cells

    Reduce responsiveness of neighboring normal neurons to block the spread of excessive electrical discharge to other parts of the brain

    SEs: Sedation and reduced cognition.
  9. AED Therapy
    • Usually starts AED therapy at a low dose and the dose is increased until seizure activity is adequately controlled
    • -Less risk of adverse reactions
    • -Helps prevent toxicity

    • -Dosage and timing may need adjusting and /or may need to add another AED to the regimen
    • -AED Drugs used for Monotherapy

    Consistency is key. If take with food, ALWAYS take with food. Don't switch from pharmacy to pharmacy or namebrand to generic. Stay consistent.
  10. Old and New med for AED
    • Old
    • Phenytoin (Dilantin)
    • Valproate (Depakote)
    • Carbamazepine (Tegretol)
    • Phenobarbital (Luminal)

    Lamotrigime (Lamictal)
  11. AED drugs used as adjunctive agents
    • Ethosuzimide (Zarontin)
    • Methsuzimide (Celontin)
    • Clonazepam (Klonopin)
    • Topiramate (Topamax)
    • Tiagabine (Gabitril)
    • Gobapentin (Neurontin)
    • Fosphenytoin Sodium (Cerebyx)
    • Primidone (Mysoline)
    • Felbamate (Felbatol)
    • Levetiracetam (Keppra)
    • Zonisamide (Zonegran)
    • Oxcarbazepine (Trileptal)
    • Pregabalin
  12. AED Drug Therapy Actions
    Older AED’s are hepatic enzyme inducers or inhibitors

    • Older AED’s--Obtain baseline and periodic laboratory studies of drug level
    • A balance between seizure control and maintaining normal behavior and cognition is necessary. Therapeutic dose is very narrow.
  13. Hydantoins
    • Identify if the product is Prompt (3-4 doses/day) or Extended.
    • Extended variety is the only one intended for one time a day dosing.
    • Serum levels should be checked frequently (7.5 – 20 mcg/ml = Therapeutic Level
    • Toxic level > 30mcg/ml
  14. Phenytoin SEs
    • Hypotension esp with IV administration
    • Drowsiness
    • Fatigue
    • Ataxia
    • Irritability
    • HA
    • Restlessness

    • Side and Toxic Effects
    • Gingival Hyperplasia (overgrowth of gums) esp in children. Dental care is essential.
    • Nystagmus
    • Dysarthria
    • Parasthesias
    • Purple glove syndrome: Hands look like they're wearing purple gloves due to vasoconstriction of capilaries. Hands will therefore be cold too.
    • Stevens-Johnson Syndrome
  15. Phenytoins Nursing Implications
    • IV administration
    • Check drug incompatibilities.
    • Only in NS (normal saline). Will precipitate if infused with any other medium or with any other medication.
    • Give only clear solutions
    • Also is an antidysrrhytmic --use with caution
    • PO Administration
    • Takes 10-14 days to reach a stable therapeutic level
    • Monitor V/S esp BP and heart rate and rhythm
    • Can take with or without food, but should be consistent
  16. Barbituates (Phenobarbital)
    GABA receptor agonists
    • Primary use to control status epilepticus
    • Causes sedation , drowsiness and depression. Give at night.
    • Alternate BC (birth control) method necessary
    • Only deep IM and IV—can cause tissue necrosis
    • Many drug incompatabilites
  17. Succinimides
    Ethosuximide (Zarontin)
    • Primary use—absence seizures
    • Monitor for anorexia (lack of appetite), nausea, vomiting and drowsiness. Take with food to help with n/v
    • Do not abruptly D/C Drug. Pt education important because pt may stop taking when seizures do not stop after several days even though Rx will not work until 10-14 days.