Anticonvulsants

Question 1

the clinical manifestation of an abnormal and excessive excitation of a population of neurons

Answer 1

seizure

Question 2

a tendency toward recurrent seizures unprovoked by systemic or neurologic insults

Answer 2

epilepsy

Question 3

occurs with an aura, epileptic cry, loss of consciousness and postural tone, tonic spasm of entire body, synchronous clonic movements, followed by confusion and sleep

Answer 3

tonic-clonic (grand mal)

Question 4

brief loss of consciousness (5-10 secs), with local or widespread clonic movements (minor muscle twitching without loss of postural tone)

Answer 4

petit mal (absence)

Question 5

in which patients do petit mal (absence) occur?

Answer 5

children

Question 6

continuous or repeated attacks, can be grand mal or petit mal

Answer 6

status epilepticus

Question 7

in which 2 acute disorders affecting the brain can status epilepticus occur in?

Answer 7

meningitis
encephalitis

Question 8

individual remains conscious, is limited to certain muscles, specific sensory changes, and autonomic activity; may remain localized or may spread causing progressive symptoms

Answer 8

simple partial seizure

Question 9

which seizure type is associated with Jacksonian Epilepsy?

Answer 9

simple partial seizure

Question 10

impaired consciousness, usually originate in temporal or frontal lobes but spread to broader areas; cause flashbacks and stereotypes movements like chewing

Answer 10

complex partial seizures

Question 11

what does treatment of a partial seizure evolving to a generalized seizure depend on?

Answer 11

type of generalized seizure that is triggered

Question 12

what is more refractory to drug treatment than the common generalized seizures?

Answer 12

partial evolving to generalized

Question 13

what is the pathophysiology of most seizures?

Answer 13

unknown etiology

Question 14

what do antiepileptic drugs treat?

Answer 14

symptom of seizure
NOT underlying epileptic condition

Question 15

what is the goal of antiepileptic drugs?

Answer 15

maximize QOL by minimizing seizures and ADRs

Question 16

which 3 anticonvulsants decrease the excitability of the focus?

Answer 16

phenobarbital
primidone
ethosuximide

Question 17

which 4 anticonvulsants prevent the spread of nervous activity?

Answer 17

phenytoin
phenobarbital
carbamazepine
valproate

Question 18

which 4 anticonvulsants enhance inhibitory mechanisms?

Answer 18

phenobarbital
primidone
valproate
benzodiazepines

Question 19

all anticonvulsants are specific for seizure type, except which one that is used for all types of seizures?

Answer 19

valproic acid

Question 20

what are many anticonvulsants used for?

Answer 20

neuropathic pain

Question 21

very painful, sharp electric-like spasms that usually last a few seconds-mins but can become constant

Answer 21

trigeminal neuralgia

Question 22

what activities can trigger trigeminal neuralgia? (5)

Answer 22

brushing teeth
chewing
drinking/eating
lightly touching face
shaving

Question 23

what is a risk factor for trigeminal neuralgia?

Answer 23

age (after 40)

Question 24

what is the major cause of trigeminal neuralgia?

Answer 24

demyelination of the axons of the trigeminal nerve

Question 25

what are 2 other uses of anticonvulsants?

Answer 25

diabetic pain bipolar disorder

Question 26

sedation can occur at therapeutic doses of anticonvulsants, except in these meds: (2)

Answer 26

phenytoin valproic acid

Question 27

why are there potential drug interactions with anticonvulsants?

Answer 27

highly protein bound

Question 28

why do some anticonvulsants reduce antibiotic efficacy?

Answer 28

some induce hepatic enzymes

Question 29

which 2 drug types decrease anticonvulsant absorption?

Answer 29

antacids antihistamines

Question 30

the first drug developed specifically to treat seizures and is non-sedating

Answer 30

phenytoin

Question 31

what is the drug of choice for generalized tonic-clonic seizures?

Answer 31

phenytoin

Question 32

what are the 4 uses for phenytoin?

Answer 32

generalized tonic-clonic seizures partial seizures status epilepticus trigeminal neuralgia

Question 33

phenytoin is used as a backup treatment for _____

Answer 33

trigeminal neuralgia

Question 34

drug that inhibits reactivation of Na channel and prevents post tetanic potentiation

Answer 34

phenytoin

Question 35

what increases the effectiveness of phenytoin in its MOA?

Answer 35

high extracellular K

Question 36

what does phenytoin do at greater than therapeutic concentrations?

Answer 36

interferes with Ca channel and neurotransmitter release

Question 37

what is special about phenytoin's elimination?

Answer 37

has zero order kinetics at high doses (small increment of dose leads to toxicity)

Question 38

what is the highest protein-bound anticonvulsant?

Answer 38

phenytoin (90%)

Question 39

a patient taking phenytoin is experiencing nystagmus, diplopia, thought disorders and sedation. what is their plasma level?

Answer 39

20

Question 40

a patient taking phenytoin is experiencing loss of consciousness, confusion, and hyperactivity. what is their plasma level?

Answer 40

30

Question 41

a patient is taking phenytoin is experiencing lethargy, stupor, and coma. what is their plasms level?

Answer 41

40

Question 42

what are the ADRs of phenytoin?

Answer 42

**P**450 inducer **H**irsutism **E**nlarged gums **T**eratogenic **O**steomalacia **I**ntereferes with B12 = megaloblastic anemia

Question 43

what can be used to treat blood dyscrasias side effects of phenytoin?

Answer 43

folate

Question 44

what can be used to prevent osteomalacia side effect of phenytoin?

Answer 44

vitamin D supplements

Question 45

what is the drug of choice for trigeminal neuralgia?

Answer 45

carbamazepine

Question 46

what are the 3 uses for carbamazepine?

Answer 46

trigeminal neuralgia generalized tonic-clonic seizures partial seizures

Question 47

drug that inhibits high frequency neuronal firing, inhibits reactivation of Na channels, and inhibits Ca influx

Answer 47

carbamazepine

Question 48

what is the half-life of cabamazepine?

Answer 48

10-20 hours

Question 49

what are the 5 ADRs of Carbamazepine? PATCH

Answer 49

**P**arkinsonism (involuntary movement) **A**plastic anemia / **A**granulocytosis **T**eratogenic / **T**aste disorder **C**onvulsions / **CNS** (dizziness, slurred speech, ataxia) **H**eadache

Question 50

a patient presents with dizziness, diplopia, drowsiness, ataxia, and slurred speech. what are they experiencing?

Answer 50

carbamazepine overdose

Question 51

one of the oldest, most effective and least toxic anticonvulsants that is the drug of choice for seizures in infants; particularly febrile

Answer 51

phenobarbital

Question 52

what are the 3 uses for phenobarbital?

Answer 52

febrile seizure in infants generalized tonic-clonic partial seizures

Question 53

drug class that enhances the binding to GABAa receptors, increasing Cl channel openings, which inhibits Ca currents, leading to decreased excitability

Answer 53

barbituates phenobarbital primidone

Question 54

what is the half life of phenobarbital?

Answer 54

50-140 hours

Question 55

what inactivates phenobarbital?

Answer 55

liver enzymes

Question 56

phenobarbital decreases the efficacy of what drugs?

Answer 56

tetracycline + other antibiotics

Question 57

how can we measure the plasma concentration of phenobarbital and other antiepileptics?

Answer 57

saliva

Question 58

what are the 2 uses for primidone?

Answer 58

generalized tonic-clonic seizures complex partial seizures

Question 59

what is the difference between primidone and phenobarbital in their PK?

Answer 59

primidone is completely absorbed after oral administration

Question 60

what is the half life of primidone?

Answer 60

5-15 hours

Question 61

what are the 5 ADR of phenobarbital and primidone (barbituates)?

Answer 61

sedation depressed cardio/pulm hepatotoxicity megaloblastic anemia osteomalacia

Question 62

phenobarbital is not teratogenic, but enhances teratogenicity of ______when combined

Answer 62

phenytoin

Question 63

what are 2 ADR specific to primidone?

Answer 63

acute toxicity acute psychosis in complex partial seizures

Question 64

what is the drug of choice for absence seizures?

Answer 64

ethosuximide

Question 65

which drug inhibits Ca channels through T-type Ca channels = reducing oscillatory behavior of thalamic neurons?

Answer 65

ethosuximide

Question 66

how can plasma concentration of ethosuximide be measured?

Answer 66

saliva

Question 67

what are the 4 ADR of ethosuximide?

Answer 67

Gi distress CNS depression (transient) bone marrow depression blood dyscrasias

Question 68

what is the preferred drug in pregnancy?

Answer 68

ethosuximide

Question 69

which drug prolongs the activation of Na channel, leading to decreased repetitive neuronal firing, inhibits T-type Ca channels, and increases GABA levels at higher than therapeutic doses?

Answer 69

valproic acid

Question 70

what are the 5 uses for valproic acid?

Answer 70

absence seizures tonic-clonic seizures myoclonic seizures partial seizures neuropathic pain

Question 71

what is the half-life of valproic acid?

Answer 71

10-15 hours

Question 72

how is valproic acid excreted?

Answer 72

in urine

Question 73

what are the 4 ADR of valproic acid? HATS

Answer 73

**H**epatotoxicity **A**bdominal (GI) distress **T**eratogenic **S**edation

Question 74

which drug class enhances the binding of GABA to GABAa receptors, increasing the frequency of opening GABA Cl channels? and at higher concentrations, act on Na channels like phenytoin and carbamazepine?

Answer 74

benzodiazepines clonazepam clorazepate diazepam lorazepam

Question 75

what are the 2 uses for clonazepam?

Answer 75

"the **clone** makes the **myoclonic absent**" absence seizures myoclonic seizures

Question 76

what is the use for clorazepate?

Answer 76

"the **lor** is only **partially** correct" partial seizures

Question 77

which 2 benzodiazepines can treat status epilepticus?

Answer 77

diazepam lorazepam

Question 78

the major metabolite of clorazepate and diazepam that has anticonvulsant activity

Answer 78

desmethyldiazepam

Question 79

what are 2 ADR of benzodiazepines?

Answer 79

tolerance w/ 1-6 mo of treatment hyperactivity in children

Question 80

which drug binds to voltage dependent Ca channels, and has a GABA analogue but does not interact with GABA receptors?

Answer 80

gabapentin

Question 81

what are the 3 uses of gabapentin?

Answer 81

partial seizures trigeminal neuralgia neuropathic pain

Question 82

how is gabapentin excreted?

Answer 82

renal, unchanged

Question 83

what are the 2 uses for lamotrigine?

Answer 83

partial seizures bi-polar depression

Question 84

MOA of lamotrigine?

Answer 84

acts on Na channels

Question 85

what is the ADR of lamotrigine?

Answer 85

"lamotrigine is a **lamo** and causes **SJS**" stevens-johnson syndrome; severe skin rash

Question 86

what drug reduces lamotrigine half life from 24 to 12 hours? why?

Answer 86

carbamazepine induces liver enzymes

Question 87

which drug increases lamotrigine half life up to 60 hours?

Answer 87

valproate

Question 88

what is the use for felbamate?

Answer 88

partial seizures

Question 89

what is the major ADR of felbamate? what did that lead to?

Answer 89

aplastic anemia bone marrow transplants

Question 90

which drug is only approved for restricted use?

Answer 90

felbamate