Antiepileptic Drugs

Question 1

Seizure

Answer 1

clinical manifestation of abnormal and excessive discharges of population of cortical neurons

Question 2

Epilepsy

Answer 2

a group of illnesses characterized by RECURRENT seizures UNPROVOKED by any acute systemic or neurologic insults

Question 3

Convulsion

Answer 3

term for uncontrolled motor manifestations, not all seizures are convulsions

Question 4

Generalized Onset Seizures

Answer 4

Absence: “petit-mal” non-convulsive
Tonic-Clonic: “grand-mal” stereotypical idea of epilepsy
Myoclonic: shock-like muscle contractions
Atonic: loss of muscle tone, aka “drop attack”

Question 5

Focal Onset (Partial) Seizures

Answer 5

Simple: No loss of impairment/consciousness, e.g. twitching of a single limb, sensory abnormality
Complex: IMPAIRED consciousness, COMPLEX motor behavior
Secondarily generalized: begin as simple or complex and morph into generalized Tonic Clonic

Question 6

Status Epilepticus

Answer 6

more than 30 min or two together with no full recovery between seizures

Question 7

Goal of AED therapy

Answer 7

NO seizure, NO med. side effects, GOOD Q.O.L.

Question 8

AED MOA & Seizure

Answer 8

T-Ca+ Channel for absence seizures
-ethosuximide, valproate, lamotrigine
Increase activity of GABA (inhibitory NTm)
Prolongation of inactive state of Na channels
Enhancement of K+ Currents

Question 9

Common AED Side Effects

Answer 9

Sedation (usually temporary), confusion, memory disturbances, Dizziness

Question 10

Serious AED adverse effects

Answer 10

Hypersensitivities: carbamaz, phenytoin, Lamictal
Hepatotoxicity: valproate, phenytoin, carbamaz
Bone marrow suppression: valproate, carbamaz

Question 11

AED Drug Interactions

Answer 11

mostly hepatic enzyme inducers, increased metabolism of other drugs, examples: phenobarb, phenytoin, “pines”
Hepatic inhibitors- valproate (increase Lamictal and Carbamazepine

Question 12

Epilepsy can lead to depression and vise versa

Answer 12

Black Box for suicidality for all AED’s (especially in the presence of depression and in the treatment of painful conditions

Question 13

Dilantin

Answer 13

Phenytoin- Focal Onset Seizures, conversion between cap and liquid, Non-linear dose dependent kinetics

Question 14

Fosphenytoin

Answer 14

phenytoin pro-drug for IV or IM

Question 15

Zarontin

Answer 15

Ethosuximide- narrow spectrum, ONLY for absence, caps and syrup, commonly for children, side effects: GI upset, sedation and headaches

Question 16

Tegretol

Answer 16

Carbamazepine- Focal onset seizures, initial sedation, GI upset, double vision

Question 17

Carbamazepine

Answer 17

Induces- 3A4 and others, AUTOINDUCTION, onset noticeable in one week max in one mo., de-induction may require complete elimination

Question 18

Carbamazepine

Answer 18

Stevens Johnson Syndrome / Toxic Epidermal Necrolysis 10 fold higher in Asians, skin rashes

Question 19

Trileptal

Answer 19

Oxcarbazepine- pro-drug for MHD, very similar to carbamazepine, better tolerated, less drug interactions, interacts with oral contraceptives

Question 20

Aptiom

Answer 20

Eslicarbazepine- active metabolite of OXC, better tolerated yet, may effect OC, single dose QHS, up to 1200mg/day

Question 21

Depakote or Valporic Acid

Answer 21

Valproate- broad spectrum (focal and general), gelcaps and syrup, ER dosage form is not equivalent

Question 22

Valporate Adverse Effects

Answer 22

N/V Heartburn, give with food, transient sedation, tremor, hair loss, weight gain, thrombocytopenia, liver damage, pancreatitis (pt. education: symptoms like flu)

Question 23

Lamictal

Answer 23

Lamotrigine- Broad Spectrum (focal and general)

Question 24

Lamictal ADE

Answer 24

diplopia, sedation, somnolence, skin rash (but less than carbamazepine

Question 25

Lamotrigine Skin Rash

Answer 25

enhanced by: concurrent VPA therapy, high starting dose, rapid dose escalation

Question 26

Lamotrigine Drug Interactions

Answer 26

Induction=increase dose requirement up to 100%
Inhibition=decrease dose requirement up to 100%
OC’s induce metabolism of Lamictal
Lamictal does not effect OC’s

Question 27

Neurontin

Answer 27

Gabapentin- increase GABA release and alters Ca+, Focal Seizures, 100% renal, mostly for pain,

Question 28

Lyrica

Answer 28

Pregabalin- from gabapentin, similar to gabapentin, more for pain, too.

Question 29

Topamax

Answer 29

Topiramate- Broad Spectrum, blocks Na+ and Ca+ channels, urine excretion

Question 30

Topamax ADE

Answer 30

> 200mg: breakthrough bleeding, contraceptive failure

Question 31

Topamax Clinical Cues

Answer 31

slow titration to avoid CNS side effects (dizziness, mental slowing, confusion), renal stones (maintain hydration), precipitation of glaucoma, hypohidrosis (diminished sweating)

Question 32

Keppra

Answer 32

Levetiracetam- Most used AED in USA, alters storage and release of neurotransmitters, Broad spectrum, no significant drug interactions

Question 33

Keppra ADE

Answer 33

depression, suicidality, iritability, aggression, hallucinate, avoid in people with Hx. of psychiatric illness

Question 34

Zonegran

Answer 34

Zonisamide- sulfonamide derivative, many MOA, clinical effects similar to topamax

Question 35

Zonegran Side Effects

Answer 35

CNS, anorexia/nausea, nephrolithiasis, hypohidrosis

Question 36

Gabatril

Answer 36

Tiagabine- increased GABA, uncommon, careful seizure diagnosis so not to precipitate underlying seizure types

Question 37

Vimpat

Answer 37

Lacosamide- mono-therapy or adjunct for partial onset seizures, diplopia, HA, dizziness, slows cardiac conduction

Question 38

Onfi

Answer 38

Clobazam- for LGS (lennnox Gastaut Syndrome)

Question 39

Retigabine

Answer 39

Ezogabine- potassium channel opener, CONFUSION, PSYCHOSIS, HALLUCINATIONS, TID, pigmentation changes (skin and eye)

Question 40

Fycompa

Answer 40

Perampanel- focal onset >12y.o., long half life, neuropsychiatirc adverse effects

Question 41

Teratogenesis

Answer 41

Caused by Phenytoin, Carbamazepine, Phenobarb, VPA