Anti-Convulsants (4-3-14)

Question 1

what mutations cause tonic-clonic?

Answer 1

Na channels
K channels
N cholinergic receptor

Question 2

what mutations cause absence?

Answer 2

T-type VGCC

Question 3

MELAS (Myoclonic seizure)

Answer 3

Mitochondrial Encephalopathy,
Lactic Acidosis,
Stroke

Question 4

MERRF (Myoclonic seizure)

Answer 4

Myoclonic Epilepsy,
Ragged Red Fibers

involves anything concerning mitochondrial function: oxidative phosphorylation, ETC

Question 5

Pentylenetetrazol toxicity? MOA?

Answer 5

used as a respiratory stimulant
high doses –> seizure
MOA = inhibit GABAa + opens Ca channels

Question 6

drugs to counteract Pentylenetetrazol induced seizure?

Answer 6

1. Ethosuximide (blocks Ca channels)
2. Valproate (increases GABA, block Na channels)
3. Benzodiazepines (Clonazepam)** = opens Cl channels

Question 7

drugs to counteract Electroshock induced seizure (used to treat suicide)

Answer 7

1. Phenytoin
2. Carbamazepine
3. Lamotrigine
   note: Benzodiazepines NOT effective

Question 8

length of Aura in Tonic-Clonic seizure? What happens during this time?

Answer 8

seconds

hallucination, dysmensia (Deja vu, Jamais vu), visceral aura

Question 9

length of tonic state in Tonic-Clonic seizure?

Answer 9

< 1 min
body rigidity
gasp

Question 10

length of clonic state in Tonic-Clonic seizure? What happens in this stage?

Answer 10

< 3min
jerking –> tongue biting
Autonomics = incontinence, tachycardia, HTN, hypersalivation, pupillary dilation

Question 11

length of flaccid coma in Tonic-Clonic seizure?

Answer 11

hours

Question 12

what seizure are you conscious for?

Answer 12

simple partial

Question 13

what seizures are you unconscious for?

Answer 13

complex partial

generalized onset epilepsy

Question 14

what is an interictal spike? What does it mean?

Answer 14

sharp EEG wave during symptom-less period

sign patient has epilepsy

Question 15

benzodiazepine can block ____-induced seizures but not ____-induced seizures

Answer 15

blocks phenylenetetrazol-induced seizures

cannot block electroshock-induced seizures

Question 16

what are the 3 major classes of anticonvulsants?

Answer 16

Na channel blockers
Ca channel blockers
GABA agonists

Question 17

What drugs act on Na channels?

Answer 17

old = carbamazepine, phenytoin, valproic acid 
new = lamotrigine, topiramate, zonisamide

Question 18

carbamazepine S/E

Answer 18

Agranulocytosis, aplastic anemia (low WBCs)
hepatoxicitiy
CNS effects: nystagmus, diplopia, tired, vertigo, headache

Question 19

carbamazepine MOA

Answer 19

Na+-channel inactivation

Question 20

Phenytoin MOA? What seizure can it NOT be used for?

Answer 20

Na+-channel inactivation

do not give for absence seizures, give ethosuximide

Question 21

Fosphenytoin sodium. When do you use it?

Answer 21

water soluble, phosphatases convert to phenytoin.
I.V./I.M. administration, no phlebitis
arrhythmias.
Used in status epilepticus

Question 22

Phenytoin S/E

Answer 22

painful phlebitis
lymphadenopathy***
osteomalacia 
gingival hyperplasia
excessive hair growth 
megaloblastic anemia (low folic acid)
double vision 
increased hepatic degradation of glucocorticoids
ataxia/nystagmus

Question 23

Valproic Acid MOA

Answer 23

a. Prolongation of Na+-channel inactivation
b. more GABA synthesis, less GABA breakdown
c. T-type calcium channel blockade

Question 24

Valproic Acid S/E

Answer 24

GI distress = Acute pancreatitis, Hepatotoxicity
Thrombocytopenia
Alopecia
Ataxia

Question 25

Valproic Acid C/I

Answer 25

Pregnancy: folate antagonist --> NTD --> meningocele/spina bifida Bleeding disorders Hepatic disease

Question 26

LAMOTRIGINE S/E

Answer 26

a. Dizziness b. Diplopia c. Sedation d. Ataxia e. Headache f. Skin rash g. Stevens-Johnson syndrome

Question 27

GABA Agonists

Answer 27

Benzos: LORAZEPAM, DIAZEPAM, CLONAZEPAM Barbituates: PHENOBARBITAL, PRIMIDONE TOPIRIMATE

Question 28

Synthesis of GABA is increased by:

Answer 28

VALPROIC ACID | VIGABATRIN

Question 29

GABA release increased by:

Answer 29

GABAPENTIN PREGABALIN -do not bind to GABA receptors, but increase release -block membrane insertion of a2d subunit of T-Type Ca channel in glutamatergic neurons

Question 30

GABA transporter inhibitor

Answer 30

TIAGABINE

Question 31

topirimate S/E

Answer 31

paresthesia kidney stones (don't give w/ CA inhibitors) weight loss fatigue, sedation, psychomotor slowing glaucoma speech or language problems hypohidrosis (decreased sweating in response to stimuli)

Question 32

phenobarbital S/E

Answer 32

sedation respiratory depression nystagmus, ataxia megaloblastic anemia -> Rx = folate

Question 33

primidone use? S/E?

Answer 33

primidone metabolized to phenobarbital!!! effective in all seizures EXCEPT ABSENCE same SE as phenobarbitol = sedation

Question 34

drug for absence epilepsy

Answer 34

ethosuximide | Block T-type Voltage Gated Ca2+-channels

Question 35

ethosuximide C/I?

Answer 35

hepatic dx | renal dx

Question 36

ethosuximide adverse effects?

Answer 36

Bone marrow suppression  can’t make as many blood cells = Leukopenia, Thrombocytopenia, Aplastic anemia Skin reactions, SLE, urticaria, pruritus Ataxia, lethargy, headache

Question 37

Step 1 in treatment for status epilepticus

Answer 37

Coma Cocktail - dextrose - thiamine - naloxone

Question 38

Step 2 in treatment for status epilepticus

Answer 38

1) Benzos: Lorazepam, diazepam (not for longterm Rx) 2) fosphenytoin 3) now refractory status epilepticus --> phenobarbital 4) if still out, give general anesthesia

Question 39

Rx for focal epilepsy

Answer 39

carbamazepine lamotrigine phenytoin

Question 40

Rx for tonic-clonic

Answer 40

valproic acid topiramate lamotrigine

Question 41

Rx for absence

Answer 41

ethosuximide* | valproic acid

Question 42

Rx for myoclonic atypical absence atonic

Answer 42

valproic acid topiramate lamotrigine

Question 43

what happens during simple partial seizure?

Answer 43

``` conscious* Motor signs Somatosensory or special sensory symptoms Autonomic signs Psychic symptoms ```

Question 44

what happens during complex partial seizure?

Answer 44

``` Aura = epigastric, limb numbness, vertigo Automatisms = hand-waving, lip-smacking Other motor (tonic posturing) ```