Antiseizure (General)

Question 1

Epileptic Seizure

Answer 1

Abnormal excessive and synchronous neuronal activity in the brain

Question 2

Epilepsy

Answer 2

• At least two unprovoked seizures that occur less than 24 hours apart
• One unprovoked seizure and a probability of further seizures of at least 60% occuring in the following 10 years
• Diagnosis of an epilepsy syndrome

Question 3

Focal Seizures

Answer 3

Seizures that are focused on one part of the brain

Question 4

Simple Partial Seizure

Answer 4

No impairment of consciousness

Motor symptoms (Muscle Twitching)

Duration < 60 seconds

Question 5

Complex Partial Seizure

Answer 5

Altered consciousness
- Not aware of surroundings
- Not unconscious

Motor automatism (Chewing or Lip Smacking)

Duration 1-2 minutes with postictal confusion after

Question 6

Secondary Generalized

Answer 6

A focal seizure that becomes generalized

Question 7

Generalized Seizures

Answer 7

Widespread involvement of brain

Can be convulsive/non-convulsive

Question 8

Generalized Tonic-Clonic (Grand Mal)

Answer 8

Loss of consciousness (Stereotypical Seizures)

Hyperextension of body, rhythmic full body contractions (Tonic and Clonic Phases)

Duration 1-2 minutes with Postictal Confusion, stupor, and headache

Question 9

Absence (Petit Mal)

Answer 9

Sudden Impairment of Consciousness
- No convulsions

Duration 5-10 seconds

Starts in childhood

Question 10

Myoclonic

Answer 10

Sudden muscle contractions, no loss of consciousness

Duration of jerks lasts milliseconds

Question 11

Pathophysiology of Seizures

Answer 11

Imbalance of Excitatory/Inhibitory
- When neuronal activity gets synchronized in the brain

Question 12

Pathophysiology of Seizures (Excitatory Mechanisms)

Answer 12

Too Much Excitatory Mechanisms
- Glutamate Receptors (NMDA, AMPA)
- Sodium and Calcium Influx

Question 13

Pathophysiology of Seizures (Inhibitory Mechanisms)

Answer 13

Not enough Inhibitory Mechanisms
- GABA
- Voltage Gated Potassium Channels
- Calcium Dependent Potassium Channels

Question 14

Antiseizure Drug Limitations

Answer 14

Suppresses seizures by inhibiting abnormal neuronal discharge (Symptomatic)

Not Curative

Question 15

Antiseizure Drugs Mechanism of Action

Answer 15

Enhancement of GABA actions
Sodium / Calcium Channel Blockers
Inhibition of Glutamate Receptors
Potassium Channel Openers

Question 16

GABA Modulators (Enhance GABA Receptor Activation)

Answer 16

Phenobarbital
Benzodiazepines

Question 17

GABA Modulators (Inhibit GABA Reuptake)

Answer 17

Tigabine (GAT 1 Inhibitor)

Question 18

GABA Modulators (Inhibit GABA Breakdown)

Answer 18

Vigabatrin (Irreversible Inhibitor of GABA transaminase)

Question 19

GABA Modulators (Increased GABA Activity)

Answer 19

Gabapentin
Pregabalin

Question 20

Sodium Channel Blockers

Answer 20

Phenytoin
Carbamazepine
Lacosamide
Lamotrigine
Zonisamide

Question 21

Sodium Channel Blockers (Targets)

Answer 21

Prolongs refractory period of Na+ Channels
–> Will only affect channels that have already fired and are inactive
–> Channel will not refire in refractory period

Question 22

T-Type Channel Activity responsible for what kind of seizures

Answer 22

Absence Seizure
(Hyperactivation of T-Type Ca2+ Channels causes absence seizures)

Question 23

T-Type Channel (ASM)

Answer 23

Ethosuximide
Valproic Acid

Both work only with absence seizures

Question 24

P/Q-Type Calcium Channel Mechanism

Answer 24

Modulates the release of neurotransmitters like GABA

Increases activity of GABA

Question 25

P/Q-Type Calcium Channel (ASM)

Answer 25

Gabapentin
Pregabalin

Question 26

Levetiracetam and Brivaracetam
- What kind of seizures
- Found where
- Mechanism

Answer 26

Works on all type of seizure (Broad-Spectrum)

Found in presynaptic neuron

Modulates neurotransmitter vesicular release of presynaptic neuron
- Bind to synaptic vesicle protein 2A (SV2A) which controls release of various neurotransmitters
–> Increased release of GABA
–> Decreased release of glutamate

Question 27

Perampanel
- Mechanism

Answer 27

Non-Competitive AMPA Receptor Antagonist
–> Prevents action of excitatory receptor

Question 28

ASM with Multiple Mechanisms

Answer 28

Valproic Acid
Topiramate
Felbamate (Lots of side effects)

Question 29

What is the rule with combining ASM

Answer 29

Do not combine drugs with the same mechanism (Phenobarbital with Barbiturate)

Can combine broad spectrum drugs, these are synergistic

Question 30

What drugs treat Focal Seizures

Answer 30

All anti-seizure drugs will work
Na+ Blockers:
- Carbamazepine, Lamotrigine, Phenytoin
Broad Spectrum:
- Levetiracetam (SV2A Modulator)

Exception: Ethosuximide (T-Type Ca2+)

Question 31

What drugs treat Generalized Tonic-Clonic Seizures

Answer 31

Na+ Blockers:
- Carbamazepine, Lamotrigine, Phenytoin
Broad Spectrum:
- Levetiracetam (SV2A Modulator)
- Valproic Acid

Question 32

What drugs treat Absence Seizures

Answer 32

T-Type Ca2+ Channel Blockers
- Ethosuximide
- Valproic Acid

Question 33

What drugs treat Myoclonic Seizures

Answer 33

Broad Spectrum:
- Valproic Acid

Question 34

What ASM should not be used to treat absence/myoclonic seizures

Answer 34

Na+ Blockers are ineffective and may worsen absence/myoclonic seizures

Question 35

Other uses of antiseizure drugs

Answer 35

Bipolar Disorder
Anxiety
Neuropathic Pain
Migraine Prophylaxis