AEDs

Question 1

Worsen Absence sz

Answer 1

Phenytoin
CBZ
Gabapentin
Lamotrigine

GABAergic agents –> GABA B receptors –> activate t-type calcium channels (implicated in thalamic mech of absence)

Question 2

Worsen myoclonic sz

Answer 2

Carbamazepine

Phenytoin

Question 3

Enzyme Inducing antiepileptics

Answer 3

Phenytoin
Phenobarbital primidone
Carbamazepine Oxcarb
Topiramate > 200 mg/d

Sig: increase metabolism oral contraceptives

Question 4

Topiramate Side Effects

Answer 4

C. Fatigue
Tingling
Word finding difficulties

S. Acidosis
Glaucoma
Kidney stones

Question 5

Phenytoin
Mechanism

            Metabolism

Answer 5

Inhibits voltage-dependent Na channel

0 order kinetics at total levels > 10-15 micg/ml

Primarily hepatic

Question 6

Phenytoin

Toxicity

Answer 6

Nystagmus
Ataxia
Dysarthria
Diplopia
Nausea
Drowsiness

Question 7

Children YOUNGER than 8
Have INCREASED clearance

Target maintenance goal 30 - 50 mg/kg

Answer 7

Oxcarbazepine
Interacts with contraceptives
Not associated with weight gain (cf. CBZ)

Question 8

Side effect presentation

Acute: HA, nausea, vomiting, tremors, delirium, sz, decerebrate posturing

Chronic: anorexia, cramps, personality change, gait prob, stupor, n/v

Answer 8

Hyponatremia

OXC. CBZ.