Drugs for Epilepsy (AEDs) 7-8

Question 1

epilepsy

Answer 1

-group of chronic neuro disorders with recurrent seizures because of excessive excitability of neurons in brain
-s/s either periods of unconsciousness to violent convulsions
-seizure: general for all epileptic events
-convulsion: abnormal motor activity (jerking)

Question 2

general for ALL AEDS

Answer 2

-suppress discharge of neurons within seizure focus
-suppress spread of seizure to other areas
MOA: suppress Na, Ca influx, suppress K efflux, block glutamate, potentiate GABA (inhibit neuronal excitability)

-cause suicidal thoughts (monitor for anxiety, agitation, mania, hostility)
-needs to be withdrawed slowly (1 med withdraw, 1 kept normal dose)
-NO use in pregnancy
-no take with alcohol
-depends on hospital: give benzo –> phenytoin
-DONT take AEDs with each other

Question 3

Lorazepam (Ativan)

Answer 3

-benzodiazepine
-for ALL types of seizures –> acts quickly (15-30min) so use for emergencies of seizures
-monitor RR, CVS, BP, HR: worry sedation and resp depress

Question 4

Phenytoin (Dilantin)

Answer 4

-MOA: selective inhibit Na channels–> suppress AP in seizure-generating neurons (but leave healthy ones unaffected)
-1st drug to suppress seizures without totally suppress CNS

Question 5

phenytoin adverse

Answer 5

-CNS: when above therapeutic: nystagmus, sedation, ataxia (uncoordinated gait), diplopia
-hirsutism, gingival hyperplasia: focus on oral care
-morbilliform rash (looks like measles bc mutation): discontinue
-dysrhythmias/CV effects with IV admin: administer slowly AND ONLY NSS (not others, will form crystals)
-NO pregnancy (decr vit K absorb, bleed risk; fetal defects)

Question 6

phenytoin interactions

Answer 6

-decrease effect of BC: increase dose
-decrease effects warfarin, glucocorticoids
-increase levels: Diazepam, alcohol (acute use)
-decrease levels: alcohol (chronic use)
-NO CNS depressants

Question 7

Carbamazepine (Tegretol)

Answer 7

-MOA: suppress high frequency neuron activity by delayed recovery of Na channels
-good for partial and tonic-clonic seizures (also bipolar, trigeminal nerve pain)
-PO only
-hepatic metabolism

Question 8

carbamazepine adverse

Answer 8

-minimal CNS: headaches
-hematologic effects: bone marrow suppression (anemia, leukopenia, thrombocytopenia) =CBC before and after
-TERATOGENIC: NO PREGNANT
-fluid overload and hypoNa: monitor s/s

Question 9

carbamazepine interactions

Answer 9

-inactivate oral contraceptives and warfarin
-phenytoin can decrease effects
-valproic acid inhibits metabolism
-NO grapefruit juice (increase peaks and troughs)

Question 10

indication for Valproic acid (Depakote)

Answer 10

-seizure: all types of seizures
-bipolar
-migraines

-hepatotoxic: have LFT, avoid children
-pancreatitis: (LUQ acute pain, pain after eat, Grey turner/cullens sign)
-VERY TERATOGENIC: highest out of all AEDs

Question 11

indication for Gabapentin (Neurontin)

Answer 11

-ONLY form of garbapentin indicated for epilepsy
-FOR neuropathic pain and migraines
-usually combo with Phenytoin or Carbamazepine
-PO only
-adverse: somnolence and no real emotions

Question 12

indication for Levetiracetam (Keppra)

Answer 12

-for partial and tonic-clonic
-drug choice for seizure prophylaxis in pts with head trauma, ICP, tumor

Question 13

Lamictal

Answer 13

-most increased risk of suicidal thoughts