Anticonvulsants

Question 1

phenobarbital

Answer 1

traditional antiepileptic
monotherapy - generalized tonic-clonic, partial seizures, IV for status epileptics
MOA - inhibit GABA receptor
SE - sedation in adults, irritability/hyperactivity in kids
- CYP3A4: increased drug metabolism - oral contraceptives

Question 2

phenytoin

Answer 2

traditional antiepileptic
monotherapy - tonic-clonic, partial seizures
MOA - prolong rate of recovery for voltage-gated NA channels
SE - interacts with warfarin and oral contraceptives
- gingival hyperplasia
- stevens-johnson syndrome - immune-mediated drug rcn - flu-like, fever, skin blistering, potentially fatal

Question 3

carbamazepine

Answer 3

traditional antiepileptic
tonic-clonic and partial seizures, manic-depressive pts
MOA - prolong rate of voltage-gated sodium channels reactivation
SE - stupor, coma, hyperirritability, drowsiness, vertigo, ataxia, blurred vision, CYP3A4

Question 4

ethosuximide

Answer 4

traditional antiepileptic
monotherapy for abscence seizures
MOA - inhibit T-type Ca channels
SE - N&V, anorexia, CNS drowsiness, lethargy, euphoria, SJS, aplastic anemia

Question 5

valproic acid

Answer 5

traditional antiepileptic
broad spectrum - monotherapy: abscence, myoclonic, partial, tonic/clonic
MOA - inhibit T-type Ca channel, prolong inactivation of Na channels, increase GABA synthesis
SE - GI: N&V, anorexia
- increase in hepatic enzymes
- CYP2C9: warfarin, other AEDs
- unsafe during pregnancy

Question 6

fosphenytoin

Answer 6

traditional antiepileptic
pro-drug of phenytoin
used to tx status epilepticus
usually used once seizures are slightly under control

Question 7

gabapentin

Answer 7

newer antiepileptic
adjunctive tx for partial seizures, neuropathic pain
MOA - binds to L-type Ca channels not endogenous GABA
SE - fatigue, ataxia, renal clearance ability needed

Question 8

oxcarbazepine

Answer 8

newer antiepileptic
monotherapy/adjunctive partial including kids
MOA - prolong Na channels
SE - dizziness, nausea, somnolence, ataxia, CYP3A4

Question 9

lamotrigine

Answer 9

newer antiepileptic
monotherapy - broad spectrum: partial, generalized tonic/clonic, LGS
MOA - prolong Na channels, inhibit Ca
SE - dizziness, ataxia, blurred vision, nausea
- rash and SJS w/ AEDs

Question 10

topiramate

Answer 10

newer antiepileptic
broad spectrum - partial and tonic/clonic seizures, LGS
MOA - inhibit Na channels, enhance GABA receptors
SE - ataxia, fatigue, somnolence, weight loss, reduce oral contraceptive levels

Question 11

levetiracetam

Answer 11

newer antiepileptic
adjunctive tx for partial, tonic/clonic, myoclonic in kids
MOA - unknown
SE - very safe, somnolence, dizziness, asthenia, no drug-drug interaction