Anti-Convulsants

what is a seizure

Brief, temporary disturbance in the electrical activity of the brain

what is epilepsy

seizure disorder characterized by recurring seizures (2 or more)

excitatory NTs in the brain

glutamine and aspartate

excitatory receptors in the brain

NMDA and AMPA

inhibitory NT and receptor in the brain

GABA and GABA-R

what are absence seizures

Also called petit mal, these may cause you may to lose focus, blink rapidly, or stare out into space for a few seconds.

what are tonic-clonic seizures

Also called grand mal, these may cause you to cry out, fall to the ground, or experience strong muscle jerking or contractions

anti-seizure drugs reduce _____ signals and enhance _____ signals

excitatory; inhibitory

most early antiseizure medications are metabolized by _____ and excreted through the ____

liver; kidneys

mechanism of Barbiturates

Enhance binding of GABA to post-synaptic receptors and increases the time that GABA A-activated Cl−channels are open.

phenobarbital is a ______-

barbituate

major adverse effect of barbituates

osteomalacia

mechanism of hydantoins (phenytoin)

Reversible binding to inactivated Na+ channels. Stabilize Na+ channels in inactivated state.

factors that can alter phenytoin protein binding and what they result in

1. Hypoalbuminemia→ Less protein to bind to; more free drug→ ↑ Unbound "free" drug

2. End-stage renal disease (creatinine clearance)→ Loss of protein via urine (i.e., proteinuria)→ ↑ Unbound "free" drug

3. Presence of "displacing" drugs (e.g., aspirin, valproic acid)→ They compete for the same binding site→ And displace phenytoin off the protein→ ↑ Unbound "free" drug

toxicity of hydantoins

fetal hydantoin syndrome

mechanism of ethosuximide

Reduce Ca2+ influx through T type Ca2+ channels

mechanism of carbamazepine

Reversible binding to inactivated Na+ channels. Stabilize Na+ channels in inactivated state.

mechanism of valproic acid

- Binding to inactivated Na+ channels.

- Reduce Ca2+ influx through T type Ca2+ channels.

- Some studies showed that it enhances GABA activity.

toxicity of valproic acid

Teratogenic: spina bifida / neural tube defects

mechanisms of GABA Drugs

1 - increased GABA receptor activation

2 - Inhibits GABA transaminase

3 - Inhibits GABA transporter 1 (GAT-1)

GABA drugs have an adjunct therapy or acute emergency treatment for ____ _____

status epilepticus

Ganaxolone is a _______ that functions by binding to the ____ ____ ____ on the ____ ____ and is used for treating ____ ____

neurosteroid; steroid binding site; GABA receptor; infantile spasms

mechanism of vigabatrin

inhibits GABA transaminase, increasing GABA concentrations

mechanism of Tiagabine

inhibits GABA transporter 1 - inhibits GABA uptake leading to increased GABA concentrations in the synaptic cleft

Mechanism of Gabapentin

Does not interact with GABA receptors, binds and inhibits L-type Ca2+ channels α2δ.

Mechanism of Lamotrigine

binds to inactivated Na+ channels

Mechanism of Levetiracetam

Synaptic Vesicle glycoprotein (SV2A) inhibition →modulates glutamate release.

What is the main aim of antiepileptic drugs?

_____stop treatment suddenly as this increases risk of _____ _____

to control seizures with the least number of drugs; NEVER; status epilepticus

Nonpharmacological treatments of epilepsy

1 - surgical resection of seizure foci

2 - implantable neurostimulatory devices

3 - ketogenic diet

What to do if a patient has a Status Epilepticus event

administer Diazepam or midazolam and call EMS