Seizures

Question 1

Causes of seizures (6)

Answer 1

• Infection
• Neoplasm
• Head injury
• Heredity
• Toxic effects
• Metabolic disorder

Question 2

Principle MOA of anti-seizure meds involve ________ and _______

Answer 2

voltage-operated ion channels and excitatory synaptic function

Question 3

What are the 3 main MOA of AEDs?

Answer 3

1. Modification of ion conductance - Na+, K+, Ca++
2. Enhancing inhibition - GABA
3. Inhibiting excitation - Glutamate

Question 4

What are the 3 types of focal onset seizures?

Answer 4

1. Focal aware - simple partial
2. Focal impaired awareness - complex partial
3. Focal to bilateral tonic-clonic - partial seizure secondarily generalized

Question 5

What are the 5 types of generalized onset seizures?

Answer 5

1. Generalized tonic-clonic (grand mal)
2. Generalized absence (petite mal)
3. Myoclonic
4. Atonic/clonic (drop attack)
5. Infantile spasms (West’s syndrome)

Question 6

What are automatisms seen in complex focal seizures?

Answer 6

• Lip smacking
• Swallowing
• Fumbling
• Scratching
• Walking about

Question 7

Focal seizures secondarily generalized look like _______ seizures

Answer 7

tonic clonic

Question 8

Differentiate between focal and generalized seizures

Answer 8

Focal - begin in specific area of brain
Generalized - begin over entire surface of brain

Question 9

Generalized tonic-clonic automatisms

Answer 9

• starts with aura
• Person falls to ground
• Entire body stiffens
• Muscles jerk or spasm
• Tongue or cheek may be bitten
• Urinary incontinence

Question 10

Seizures where muscles suddenly contract and stiffen

Answer 10

tonic

Question 11

Seizures where there is a sudden loss of muscle tone

Answer 11

atonic

Question 12

Seizures that make the body jerk like it is being shocked

Answer 12

Clonic and myoclonic seizure

Question 13

What age do infantile spasms begin?

Answer 13

Usually begins before age of 6 months

Question 14

Phenytoin MOA

Answer 14

all - mainly Na+, gaba, and glutamate receptors

Question 15

What is the more soluble prodrug of phenytoin that can be administered IV?

Answer 15

Fosphenytoin

Question 16

What type of seizures is phenytoin used to treat?

Answer 16

Partial and tonic-clonic seizures

Question 17

Which drugs compete with phenytoin for albumin binding sites?

Answer 17

Carbamazepine, sulfonamides, valporic acid

Question 18

Which drug can displace phenytoin from albumin binding sites?

Answer 18

valporic acid

Question 19

Differentiate between therapeutic, free, toxic, and lethal levels of phenytoin

Answer 19

• Therapeutic: 10-20 mcg/ml
• Free phenytoin: 1-2.5 mcg/ml
• Toxic: 30-50 mcg/ml
• Lethal: >100 mcg/ml

Question 20

What is the T1/2 of phenytoin?

Answer 20

12-36 hours

Question 21

What are the toxic effects of phenytoin?

Answer 21

• Nystagmus
• Loss of extraocular pursuit of movement
• Diplopia
• Ataxia
• Sedation

Question 22

What are the toxic effects of phenytoin with chronic use?

Answer 22

• Gingival hyperplasia
• Hirsuitism
• Coarsening of facial features

Question 23

Carbamazepine (Tegretol) MOA

Answer 23

Blocks Na+ channels

Question 24

What kind of antidepressant is carbamazepine?

Answer 24

TCA

Question 25

What is the clinical use for carbamazepine?

Answer 25

- Drug of choice for focal seizure - Can be used with phenytoin - Effective in trigeminal neuralgia - Also useful for bipolar disorder

Question 26

What is the drug of choice for a focal seizue?

Answer 26

Carbamazepine (Tegretol)

Question 27

When does Carbamazepine (Tegretol) peak?

Answer 27

6-8 hours

Question 28

Carbamazepine (Tegretol) is ___% bound to plasma proteins

Answer 28

70%

Question 29

What is the T1/2 of Carbamazepine (Tegretol)?

Answer 29

T1/2 after one dose = 36 hours T1/2 during continuous therapy = 20 hours

Question 30

______ is an autoinducer of hepatic enzymes (P450) used to treat seizures

Answer 30

Carbamazepine (Tegretol)

Question 31

What are the drug interactions for Carbamazepine (Tegretol)?

Answer 31

- Phenytoin - Phenobarbital - Ethosuxemide - Valproic acid - Clonazepam

Question 32

What are the clinical uses for Lacosamide (Vimpat)?

Answer 32

focal seizures

Question 33

What is the MOA of Lacosamide (Vimpat)?

Answer 33

Blocks sodium channels

Question 34

What are the toxic effects of Lacosamide (Vimpat)?

Answer 34

- Dizziness, nausea, HA, diplopia - Minimal drug interactions

Question 35

The oldest and safest AED available is _____

Answer 35

phenobarbital

Question 36

What is the MOA of Phenobarbital?

Answer 36

Unknown - Enhances inhibitory transmission (+ GABA), decreases excitatory transmission, may suppress abnormal neurons

Question 37

What is the AED drug of choice for infants?

Answer 37

Phenobarbital

Question 38

What are the clinical uses of Phenobarbital?

Answer 38

- Focal seizures - Generalized tonic-clonic seizures - Tried in virtually every seizure type

Question 39

What seizure types can be made worse by phenobarbital?

Answer 39

Generalized seizures: absence, atonic attacks, or infantile spasms

Question 40

What is the #1 toxic effect of phenobarbital?

Answer 40

SEDATION

Question 41

What are symptoms of overdose of phenobarbital?

Answer 41

- unsteady gait - slurred speech - confusion - respiratory depression - coma

Question 42

What type of seizures is Lacosamide used as an adjunct?

Answer 42

Focal seizure

Question 43

What is the MOA of Lamotrigine? What kind of seizures can it treat?

Answer 43

MOA –ion channel; partial & absence

Question 44

How can GABA analogs be used to treat seizures? What is an example?

Answer 44

adjunct, partial, neuralgia (Vigabatrin)

Question 45

What are the main 4 drugs used to treat focal and generalized tonic-clonic seizures?

Answer 45

Phenytoin Carbamazepine Lacosamide Phenobarbital

Question 46

How are infantile spasms treated?

Answer 46

palliative, steroids, Vigabatrin (GABA analog)

Question 47

What are the 2 main drugs used to treat generalized seizures (not tonic-clonic)?

Answer 47

Ethosuzimide and Valproic acid

Question 48

What is the drug of choice for absence seizures?

Answer 48

Ethosuximide

Question 49

What is the MOA of Ethosuximide?

Answer 49

Calcium channel inhibition

Question 50

What are the toxic effects of Ethosuximide?

Answer 50

Gastric distress (pain, N/V) and lethargy

Question 51

What is the MOA of valproic acid?

Answer 51

Unknown, hypotheses: All - Blocks sustained high frequency firing - Effects on Na+ currents - Increase GABA - Increase membrane K+ conductance (high levels)

Question 52

What is known as the "Broad spectrum AED”?

Answer 52

Valproic acid

Question 53

What are the clinical uses of valproic acid?

Answer 53

- Absence seizures - Some types of myoclonic seizures - Generalized tonic-clonic - Bipolar disorder - Migraine prophylaxis

Question 54

What are the Valproic acid toxic effects?

Answer 54

- GI - N/V - Pain - Heartburn

Question 55

What is the MOA of benzodiazepines?

Answer 55

Increased GABA – depresses all levels of the CNA

Question 56

Diazepam (Valium) pharmacokinetics

Answer 56

Long T1/2 (20-100 H), short duration (30 min.)

Question 57

What is the clinical use of benzodiazepines in seizure treatment?

Answer 57

Status epilepticus and absence

Question 58

What are the 4 options for seizure treatment?

Answer 58

– Antiepileptic drugs – Surgery – Vagus nerve stimulation – Ketogenic diet (children)

Question 59

What is the most common form of status epilepticus seizures?

Answer 59

generalized tonic-clonic

Question 60

What is the treatment for status epilepticus?

Answer 60

Sedation – IV (diazepam, fosphenytoin, phenobarb)

Question 61

What are the drugs to avoid perioperatively that can stimulate seizure activity?

Answer 61

Methohexital, sevoflurane, meperidine (Demerol)

Question 62

The only narcotic that stimulates seizure activity is ______

Answer 62

meperidine (Demerol)

Question 63

What are the effects of phenytoin use on NMB?

Answer 63

Chronic phenytoin therapy makes patient resistant to neuromuscular blocking agents Phenytoin can enhance NMB (acute)