Anti-Convulsants Flashcards
What is a partial seizure
Seizure in one hemisphere
Simple partial seizure:
Consciousness
Progress to what
No loss of consciousness
Auras (loss of consiousness)
Complex partial seizure
Impairment of consciousness
If a partial seizure becomes generalized, it is called what?
The process that leads to this
Secondarily generalized seizure.
Kindling
Generalized seizures originate where
Both cerebral hemispheres
Two types of generalized seizure
Convulsive
Non-convulsive
The one convulsive seizure type
Tonic-clonic
Tonic clonic:
Onset
Which phase first? Describe. Length?
Which phase second? Describe
Abrupt
Tonic first: Contractions with arm and legs becoming extended. Lasts 10-20 secs
Clonic second: Muscle relaxation due to exhaustion
Three non-consulsive types
Absence
Myoclonic
Atonic
Absence seizure: Describe Consciousness EEG pattern Atypical version difference
Sudden onset with brief seizures (zoning out)
Lose consciousness
3 Hz Spike and wave pattern
Less defined onsets/offsets
Myoclonic
Describe
Consciousness
Shock-like muscle contractions
No loss of consciousness
Atonic
Describe
Consciousness
2 other names
Loss of muscle tone
Loss in postural muscle tone (seem frozen)
Consciousness impaired
Drop attacks or astatic seizures
Status epilepticus?
Seizures with 30 mins or less frequency
Therapeutic goal of treating these
Control the seizures
When to use polypharmacy to treat?
After trying 3 other drugs first
When can you start to end anti-seizure meds?
After 3 years or more of being seizure free
How to taper off anti-seizure meds?
Slowly one at a time.
3 goals of treating seizures
- Treat the focal seizure
- Prevent seizure from spreading
- Treat underlying cause
3 ways to inhibit seizures
- Enhance inhibitory like through GABA
- Diminish excitatory like calcium channels
- Sodium channel blockade
When to figure out therapeutic blood levels
blood level of drug when patient has favorable response
3 early signs of toxicity of anti-seizure med
Sedation
Ataxia
Nystagmus
8 other toxic changes from anti-seizure meds
Teratogenic Hepatic toxicity Renal toxicity Behavioral changes Coag disorder Weight change Osteoporosis Hyponatremia
5 Sodium Channel blockers
- Phenytoin
- Fosphenytoin
- Carbamazepine
- Lamotrigine
- Felbamate
Phenytoin/Fosphenytoin (Phone tow-truck)
Should you use generics?
Kinetics at therpeutic plasma levels
No
Zero order
Phenytoin 5 side effects 3 seizure indications 1 non-seizure indication 2 Contra-I's Interactions (2)
SE: Nystagmus, Ataxia, gingival hyperplasia, hirsutism, p neuropathy
Seizure: Tonic-clonic, All partials, Status epilepticus
Non-seizure: Cardiac
Contra-I’s: Absence and Myoclonic
Interactions: Protein binding and biotransformation
Fosphenytoin
Difference from phenytoin:
Different admin (2):
One problem
DIff: Water soluble with fast onset
Admin: IM or parenteral
Name gets confused, drug dispensing error
Carbamazepine (Car bomb) Non-seizure use (2) Three organs affected Primary indication Other One requirement when using this drug
Mood stabilizer for mania and bipolar + Anti-psychosis
Liver, kidney, bone marrow
Primary: Partial Seizure
Other indication: Tonic-clonic
Requirement: Have to check renal, hepatic, BM function
Less toxic form of carbazepine
Derivative of carbamazepine
Lamotrigine (Lamborghini)
Similar to what
Two different SE’s
Phenytoin
Stevens-Johnson rash + epidermal necrolysis
Felbamate (Vegimite Fell)
Use
2 Main SE:
Use when patient doesn’t respond to anything else
SE: Aplastic anemia and stevens-johnson syndrome
Phenobarbital/Primidone Primary mech Biotransformation unique feature Use similar to Contra-I?
Na channel blockade dominates
Auto-induction
Use similar to phenytoin
Do NOT use in absence or myoclonic epilepsy
Primidone Mech (2) Biotransformed to (2) High primidone: PB ratio indicates what
Block inactive Na channels + Enhance GABA inhib
PHenobarbital + PEMA
indication of poor compliance with normally low phenobarbital accumulation
Valproic Acid Special title Mech (3) Protein binding fact Seizure use Toxicity 3 interactions
Best seizure drug probably
Mech: GABA enhance, Block Na+, Block Ca+,
Protein binding: Near saturation
Use: All seizures
Toxicity: Very toxic below the diaphragm (liver, alopecia, pancreas, teratogenic)
Interactions: Bio-T, PB, Clonazepam
Topiramate Similar to Extra mechanism Indicated for Non-seizure use Drug Interaction special feature
Similar to valproic Also is carbonic anhydrase All seizures Migraines Low incidence of drug interactions
Benzodiazepines
3 drugs
Mech (2)
Special feature in terms of anti-epileptic activity
3 drugs: Diazepam, Lorazepam, Clonazepam
Mech: GABA inhib and sodium blocking
Feature: Can all of the sudden stop being anti-convulsant
Ethosuximide Special feature Mechanism Best for what seizure Safety
The drug for absence epilepsy
Blocks T calcium currents
Absence epilepsy
Very safe at normal dose (toxic high)
Zonisamide Type of drug Indicated for Mechanism Minor mechanism Half life Adverse reaction (1)
Sulfonamide Partial seizures Block sodium channels Inhibit carbonic anhydrase Long half life Sulfonamide allergy
Lacosamide
Mech
Indicated for
Slows Inactivates volgate-gated sodium channels
Partial seizures
Tiagabine
Mech
Indicated for
Half life feature
Mech: Inhibit GABA uptake
Indicated: Partial seizures
Half life: Short so tough dosing
Levetiracetam
Indicated for
Mechanism
Adjunct in all seizures
Inhibitory to kindling
Ezogabine
Mechanism
a
