Antiepileptic Drugs Flashcards
Define primary (aka idopathic epilepsy)
Epilepsy without an identifiable cause
Define Secondary (aka symptomatic) epilepsy
Epilepsy that has a distinct cause such as trauma, infection, cerebrovascular disorder, etc.
What is the difference between a “Generalized Onset Seizure” and a “Partial Onset Seizure”?
1) Generalized Onset Seizure - Characterized by neuronal activity that originates simultaneously in the gray matter of both hemispheres.
2) Partial Onset Seizure - Originates in a localized or focal region (e.g., one lobe) of the brain.
What 6 things classify a Simple Partial Seizure?
1) No impaired consciousness
2) Motor symptoms
3) Hallucinations of sight, hearing, or taste
4) Tingling
5) ANS response
6) Personality changes
What 5 things classify a Complex Partial Seizure?
1) Impaired consciousness
2) Memory impairment
3) Purposeless behavior
4) Aura
5) Tonic, clonic, or tonic-clonic seizures
What 4 things classify a Generalized Seizure?
1) Both cerebral hemispheres involved
2) Tonic, clonic, myoclonic, atonic, or tonic-clonic seizures and infantile spasms possible
3) Brief loss of consciousness for a few seconds with no confusion
4) Head drop or falling-down symptoms
What is believed to be the mechanism of action of antiepileptic drugs?
Antiepileptic drugs are believed to alter the movement of sodium, potassium, calcium and magnesium ions, which results in more stabilized and less excitable cell membranes.
What are the 3 pharmacologic effects of antiepileptic drugs?
1) Increase threshold activity which reduces the nerve’s response to incoming signal.
2) Limit the spread of a seizure from its origin
3) Decrease the speed of a nerve impulse conduction
What are the 5 class of drugs used to manage seizure disorders?
1) Barbiturates
2) Benzodiazepines
3) Hydantoins
4) Iminostilbenes
5) Miscellaneous Drugs
Why should carbamazepine not be given with grapefruit juice?
Coadministration leads to increased toxicity of the antiepileptic drug.
What are the 2 types of Hydantoin drugs?
1) Phenytoin
2) Fosphenytoin
What are the 7 adverse effects of Hydantoins?
1) Nystagmus
2) Ataxia
3) Dizziness
4) Drowsiness
5) Rash
6) Gingival Hyperplasia
7) Blood dyscrasias
Name 5 advantages of Phenytoin that make it the number one prescribed antiepileptic drug.
1) Well tolerated
2) Highly effective
3) Cheap
4) Can be given via PO or IV
5) Long-Half Life - means less daily dosing and increased PT adherence to drug therapy.
Exaggerated Phenytoin effect can be seen in PTs with what condition? What can be done?
Patients with very low serum albumin. In these PTs it may be necessary to maintain Phenytoin levels well below 20 mcg/mL
What is the therapeutic drug range of Phenytoin?
10 to 20 mcg/mL
What is the advantage of Fosphenytoin over Phenytoin?
Fosphenytoin is a prodrug of Phenytoin that can be given via IM or IV without causing the burning sensation.
What are the 3 contraindications of Carbazepine (an Imiostilbenes)?
1) Myoclonic seizures
2) Absence seizures
3) Bone marrow depression
What is Autoinduction and which drug is associated with it?
Carbamazepines are associated with autoinduction, a process in which, overtime, a drug stimulates the production of enzymes that enhance its own metabolism, which leads to lower than expected drug concentrations.
What are the 2 drugs in the Iminostilbene class of atiepileptic drugs?
1) Carbamazepine
2) Oxcarbazepine
What are the 3 adverse effects of the Iminostilbene class of antiepileptic drugs?
1) Behavioral changes
2) Unusual eye movements
3) Mental or mood changes
What are the 7 miscellaneous drugs used as antiepileptics?
1) Gabapentin 2) Pregabalin
3) Lamotrigine 4) Levetiracetam
5) Tiagabine 6) Topiramate
7) Zonisamide
Which Miscellaneous antiepileptic drug can cause the serious adverse effect known as “Stevens-Johnson Syndrome”?
Lamotrigine
Which miscellaneous antiepileptic drug can cause paradoxical seizures when used for “off label” indications?
Tiagabine
Which miscellaneous antiepileptic drug is indicated for postherpetic neuralgia neuropathic pain.
Gabapentin
