Seizure Medications

Question 1

Levetiracetam/Keppra uses

Answer 1

Go-to, used in all seizure types

Question 2

Keppra dosing

Answer 2

500mg BID, titrate q2w until at max recommended dose of 1.5g BID

Question 3

Keppra side effects

Answer 3

Well tolerated, some weight gain

Question 4

Keppra monitoring

Answer 4

Dose adjust based on GFR- watch renal function

Question 5

Keppra enhances what drugs?

Answer 5

CNS depressants

Question 6

Oxcarbazepine uses

Answer 6

Adjunctive therapy in partial seizure treatment in children 6+

Question 7

Initial oxcarbazepine dosing

Answer 7

5mg/kg/day, weekly increments of 5mg/kg/day

Question 8

Target oxcarbazepine dosing

Answer 8

30-50mg/kg/day

Question 9

Dosing frequency of oxcarbazepine

Answer 9

BID

Question 10

Oxcarbazepine side effects

Answer 10

Most common in children: somnolence, HA, dizziness, N/V, rash is potentially fatal but reversible

Question 11

Oxcarbazepine monitoring

Answer 11

Sodium, hepatic function
Get baseline electrolytes and hepatic enzymes

Question 12

Oxcarbazepine and drug interactions

Answer 12

Lower potential for drug interactions because of low protein binding, hepatic enzyme induction, MHD eliminated by the kidneys

Question 13

Lamotrigine uses

Answer 13

Partial onset seizures

Question 14

Initial lamotrigine dose

Answer 14

0.5mg/kg/day divided BID x2 weeks, then 1mg/kg/day x2 weeks, then increase 1mg/kg/day q2w until response

Question 15

Maintenance lamotrigine dose

Answer 15

5-15mg/kg/day div BID

Question 16

MDD of lamotrigine

Answer 16

400mg/day

Question 17

When does the dose of lamotrigine need to be decreased?

Answer 17

Patients taking VPA

Question 18

Lamotrigine side effect

Answer 18

SJS! More likely to occur with fast titration

Question 19

Other info about lamotrigine

Answer 19

Broad spectrum of activity, low teratogenic potential, nonsedative

Question 20

Gabapentin uses

Answer 20

Partial seizures, also useful in comorbid neuropathic pain/mood stabilization in BPD

Question 21

Initial gabapentin dosing

Answer 21

30mg/kg/day

Question 22

Max gabapentin dosing

Answer 22

1800mg/day

Question 23

Dosing frequency of gabapentin

Answer 23

TID

Question 24

Gabapentin side effects

Answer 24

Somnolence, dizziness, ataxia, weight gain with higher doses

Lower incidence of neurotoxic side effects

Question 25

That one weird fact about gabapentin

Answer 25

Doses 2-3x higher often necessary to achieve max benefits With a higher dose, lower % is absorbed

Question 26

Gabapentin interactions with other drugs

Answer 26

No PK interactions, pure renal elimination and no binding to serum proteins

Question 27

Phenytoin use

Answer 27

Generalized seizures

Question 28

Phenytoin dosing

Answer 28

200-400mg

Question 29

Concentration-dependent phenytoin side effects

Answer 29

nystagmus, double-vision, blurred vision, incoordination, drowsiness, dizziness, HA

Question 30

Idiosyncratic phenytoin side effects

Answer 30

aplastic anemia, granulocytopenia, hepatotoxicity, rash, SJS, Lupus-like reaction

Question 31

Chronic phenytoin side effects

Answer 31

gingival hyperplasia, acne, hirsutism, peripheral neuropathy, chronic cerebellar damage, megaloblastic anemia, osteoporosis, fetal vitamin K depletion

Question 32

Phenytoin monitoring

Answer 32

Baseline CBC and liver enzymes, bone density screen for osteoporosis, normal TDM stuff

Question 33

Phenytoin PK/PD: protein binding

Answer 33

Highly protein bound

Question 34

Phenytoin PK/PD: hepatic metabolism

Answer 34

Capacity-limited

Question 35

Phenytoin tmax

Answer 35

4-12h

Question 36

Phenytoin PK/PD: toxicity

Answer 36

Has both concentration independent and dependent toxicity

Question 37

Fosphenytoin is used when?

Answer 37

IV, usually given in status epilepticus after IV benzo administration

Question 38

Valproate initial dosing

Answer 38

15mg/kg/day initially in 2-3 divided doses, increasing in 5-10mg/kg/day increments at weekly intervals to a max of 60mg/kg/day

Question 39

Valproate maintenance dosing

Answer 39

15-40mg/kg/day in 3 divided doses

Question 40

When to reduce starting dose of valproate

Answer 40

Elderly patients

Question 41

Valproate side effects

Answer 41

N/V/D, abdominal cramps, transient elevations in LFTs Occasionally: drowsiness, ataxia, tremor, behavioral disturbances, transient hair loss, asymptomatic hyperammonemia, weight gain

Question 42

Drowsiness and ataxia are more likely in patients taking valproate with what?

Answer 42

Other AEDs

Question 43

Valproate monitoring

Answer 43

Baseline LFTs, platelets, repeat LFTs frequently (esp. in first 6 months of treatment) Monitor coagulation tests prior to surgery

Question 44

Valproate CI

Answer 44

Hepatic disease/dysfunction

Question 45

Target valproate levels

Answer 45

50-120mg/L

Question 46

Drugs that can lower valproate levels

Answer 46

Carbamazepine, lamotrigine, phenytoin, rifampin

Question 47

Drugs that can increase valproate levels

Answer 47

ASA, chlorpromazine, cimetidine, felbamate

Question 48

Drugs levels that can increase by valproate

Answer 48

Lamotrigine, phenobarbital

Question 49

Valproate can do what to other AEDs at protein binding sites?

Answer 49

Displace them

Question 50

Carbamazepine uses

Answer 50

Partial and secondary generalized seizures

Question 51

Adult dosing for carbamazepine

Answer 51

600-2,000mg/day

Question 52

Kids dosing for carbamazepine

Answer 52

10-40mg/kg/day

Question 53

Carbamazepine dosing frequency

Answer 53

TID or QID, but BID for SR formulation

Question 54

Carbamazepine side effects that can be minimized by slow titration

Answer 54

dizziness, drowsiness, HA, diplopia, N/V

Question 55

Carbamazepine side effects: hyponatremia and water intoxication...what's it caused by?

Answer 55

Carbamazepine monotherapy, elevated serum levels, age >25, vomiting, diarrhea

Question 56

Carbamazepine monitoring

Answer 56

Baseline CBC and platelet counts Serum levels once weekly in first month of therapy

Question 57

Target carbamazepine serum levels

Answer 57

4-12mg/L

Question 58

Carbamazepine and MAOIs

Answer 58

D/C MAOI at least 14 days before starting carbamazepine

Question 59

Carbamazepine can do what to CYP3A4 drugs?

Answer 59

Stimulate their metabolism

Question 60

Drugs that can inhibit carbamazepine metabolism

Answer 60

Cimetidine, clarithromycin, danazol, erythromycin, fluoxetine

Question 61

How long does it take for carbamazepine and valproate to reach Css?

Answer 61

2-4 days That may not last for long with carbamazepine because it goes through autoinduction

Question 62

Topiramate uses

Answer 62

Focal (partial) onset seizures, primary generalizes tonic-clonic seizures

Question 63

Topiramate initial dosing

Answer 63

50mg/day, increase in 50mg dose increments until max dose of 200mg/day in 1-2 divided doses. Could go up to 400mg/day depending on formulation

Question 64

Topiramate elderly dosing

Answer 64

25mg/day, titrated up 25mg weekly until effective dose reached

Question 65

Topiramate kids dosing

Answer 65

initial- 1-3mg/kg/day at night x1 week, increase at 1-2 week intervals. Maintenance: 5-9mg/kg/day, max is 400mg/day

Question 66

Topiramate side effects

Answer 66

Dizziness, drowsiness, fatigue, metabolic acidosis, kidney stones, secondary acute angle closure glaucoma, hypohidrosis, hyperthermia, suicidal ideation, anorexia/weight loss, finger/toe numbness

Question 67

Topiramate monitoring

Answer 67

Electrolytes, SCr, acute acidosis, ammonia levels, IOP, screen for eating disorder

Question 68

Topiramate has synergistic effects with what other AED and why?

Answer 68

Lamotrigine, because they have different MoAs!