AEDs

Question 1

what is the protocol for weaning people off AEDs?

Answer 1

SLOWLY + if person is on more than one AED, discontinue one at a time

Question 2

what are the 4 traditional AED prototypes?

Answer 2

1. phenytoin
2. fosphenytoin
3. carbamezepine
4. valproic acid

Question 3

what are the 2 newer agents for AEDs?

Answer 3

1. gabapentin

2. pregabalin

Question 4

compare and contrast traditional AEDs and newer agents

Answer 4

EQUAL job of preventing SE

ACUTE (1st starting drug) side effects are equal

newer agents better tolerated, less drug drug interactions, safer with pregnancy

newer agents MORE EXPENSIVE (“the one con”)

Question 5

what is the most widely used traditional agent + mainstay of epilepsy tx?

Answer 5

phenytoin (dilantin)

Question 6

what is the therapeutic index for phenytoin?

KNOW THIS; NCLEX question

Answer 6

10-20 mcg/mL

VERY narrow

Question 7

describe what “saturation kinetics” is with phenytoin therapy?

Answer 7

liver easily gets overwhelmed –> doesn’t take much for someone to get toxic

Question 8

what are the s+s of phenytoin toxicity? (5)

Answer 8

1. nystagmus
2. sedation
3. ataxia
4. diplopia
5. blurred vision

too much phenytoin = lookin’ like you drunk

(the usual s+s…just extra!!)

Question 9

SE of phenytoin (3)

+ which one is worse @ start of therapy, but improves over time?

Answer 9

1. drowsiness worse @ start; improves over time
2. gingival hyperplasia
3. GI

Question 10

how can we educate pts on prevention/management of gingival hyperplasia with phenytoin therapy?

Answer 10

massage gums, flossing, brushing teeth, regular dental care, folic acid supplements

ORAL HYGIENE

Question 11

how can we combat the GI upset with AED use?

Answer 11

give with food

Question 12

what are the rare but serious AE of phenytoin?

Answer 12

RASH:

1. toxic epidermal necrolysis
2. SJS

REPORT

Question 13

can preggos use phenytoin?

Answer 13

NOOOO - teratogenic

Question 14

what are the administration parameters for IV phenytoin?

Answer 14

1. SLOW

no faster than 50mg/min

Question 15

how can we avoid purple glove syndrome in IV phenytoin?

Answer 15

NO subcutaneous or IM

NOT in hand veins (only large)

Question 16

what is the AED that’s the prodrug? what is it converted to in the body?

Answer 16

prodrug: fosphenytoin

converted to phenytoin

“fosphenytoin is the foster brother to phenytoin, they’re similar but VERY different”

Question 17

what is the dosing for fosphenytoin?

Answer 17

DIFFERENT than phenytoin - dosed in phenytoin equivalents (PE)!!!!

Question 18

what are the SE of IV fosphenytoin?

Answer 18

temporary paresthesia + itching in groin

(resolves ~ 10 mins after dose)

“the foster brother has crabs, but they get better in 10 mins”

Question 19

what CV SE can we see with fosphenytoin if given too quickly via IV?

Answer 19

severe hypotension + arrhythmias

Question 20

what are the SE of carbamezepine?

Answer 20

the usual

CNS (HA, ataxia, nystagmus, blurred vision, sedation)

Question 21

what are the rare AE of carbamezepine? + based on this, what should we educate patients to report?

Answer 21

1. bone marrow suppression
   =leukopenia, anemia, thrombocytopenia

• report sore throat, fever, bruising*
  2. life threatening rashes: SJS + TEN

Question 22

what genetic screening should certain patient populations undergo for carbamezepine therapy? why?

Answer 22

asian patients for HLA-B*1502

for increased risk of toxic epidermal necrolysis + SJS

Question 23

what are the severe AEs of carbamezepine

Answer 23

rash (TEN + SJS) + blood dyscrasisas

Question 24

what is the unique characteristic of carbamezepine re: half life?

Answer 24

this drug increases its own metabolism –> decreased half life over time

Question 25

what drug food interactions occur with carbamezepine?

Answer 25

grapefruit

+ LOTS of drug-drug interaxns

Question 26

what is most common SE of valproic acid?

Answer 26

GI upset

“acid burns the stomach!!”

Question 27

what are the (3) rare but serious AE of valproic acid?

Answer 27

1. hepatotoxicity
2. pancreatitis
3. blood dyscrasias (leukopenia, anemia + thrombocytopenia)

Question 28

which AED is the MOST teratogenic?

Answer 28

valproic acid

“you shouldn’t give acid to babies”

Question 29

what is important teaching point for valproic acid (PO admin)?

Answer 29

don’t crush or chew tablets - swallow whole

can open + sprinkle capsules if if difficulty swallowing

Question 30

what is dosing like for gabapentin therapy for seizure tx?

Answer 30

HIGHER doses

Question 31

what are SE of gabapentin? what’s unique about them?

Answer 31

(CNS)
sedation, somnolence, dizziness, ataxia, fatigue, nystagmus

*especially pronounced when starting drug, like traditional AEDs, but IMPROVE OVER TIME ◡̈ *

Question 32

what are the SE of pregabalin?

2 are unique and different

Answer 32

(CNS)

sedation, dizziness, somnolence, blurred vision, WEIGHT GAIN + EUPHORIA

Question 33

pregabalin (Lyrica) is what schedule drug?

Answer 33

schedule 5 (due to euphoria)

Question 34

if someone is in active seizure, what drug therapy would you expect to give?

Answer 34

BENZOS (“calming down GABA”)

ex: lorazepam, diazepam, midazolam

Question 35

what is IV admin rate for lorazepam?

Answer 35

2mg/min

Question 36

what is IV admin rate for diazepam?

Answer 36

5mg/min

Question 37

which SE of AEDs is common when starting, but generally improves over time?

Answer 37

Sedation

Question 38

AEDs shouldn’t be taken with what other drug classes + why?

Answer 38

other CNS depressants (ETOH, opioids, antidepressants)

= SAFETY RISK

Question 39

what should be considered with pregnancy and AED therapy?

Answer 39

risk ratio - is it more harmful for person carrying fetus to have seizure? or is drug more harmful to fetus?

Question 40

what’s important teaching point to patients on AEDs re: oral contraceptives?

Answer 40

AEDs decrease the effectiveness of OCPs!!!