PHARM - anti-epileptic drugs Flashcards Preview

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Flashcards in PHARM - anti-epileptic drugs Deck (63):
1

4 types of AEDs

- Na blockers
- Ca blockers
- GABA agonists
- glutamate antagonists

2

Na blockers

- phenytoin
- carbamazapine
- valproate
- topiramate
- lamotrigine

3

Ca blockers

ethosuximide

4

GABA agonists

- topiramate
- barbs
- benzos
- gabapentin?

5

glutamate antagonists

- topiramate
- lamotrigine

6

absorption is essentially complete for all AEDs except...

gabapentin, which has a saturable transporter at high doses

7

speed of AED absorption

- takes hours
- slowed by food

8

TIs in AEDs

generally good but hard to compare

9

typical cytochrome P-450 enzymes

2C9, 2C19, 3A4

10

some UGTs and what they metabolize

1A9 - valproate
2B7 - valproate, lorazepam
1A4 - lamotrigine

11

what do cytochrome P-450 inducers do?

- increase clearance and decrease steady state concentrations of other drugs
- phenobarbitol, ethosuximide, phenytoin, carbamazepine, tobacco

12

what do cytochrome P-450 inhibitors do?

- decrease clearance and increase steady state concentrations of other drugs
- erythromycin, valproate, fluconasol, trimethoprim, Ca blockers

13

what pharmacokinetic factors change in the elderly?

distribution - more fat, less albumin
metabolism slowed - less hepatic enzyme, less blood flow
excretion - less renal clearance

14

pharmacokinetic factors in pediatrics

neonates - need lower doses, low protein binding and metabolic rate
children - need higher per kg doses, faster metabolism

15

pharmacokinetic factors in pregnancy

- increased volume of distribution
- low serum albumin, but may not affect free drug level
- faster hepatic metabolism
- may need higher AED doses, but not as high as predicted

16

drug of choice for pregnancy

lamotrigine, few side effects

17

AEDs that cause weight gain

gabapentin, valproate, carbamazepine

18

AEDs that cause weight loss

topiramate

19

AEDs associated with PCOS

- carbamazepine
- valproate

20

AEDs associated with osteoporosis

- phenobarbitol
- carbamazepine
- phenytoin

21

phenobarbitol effective for:

all seizure types but absence

22

phenobarbitol mechanism

GABA agonist, opens Cl channels for hyper polarization

23

phenobarbitol metabolism

- PO or IV
- inducer
- hepatic metabolism
- needs to be loaded
- half life 100hrs

24

phenobarbitol toxicity

- hyperactivity in children
- sedation in adults
- joint problems

25

phenytoin used for

- all seizure types except absence
- better for localized and secondary generalized than for primary generalized

26

phenytoin mechanism

blocks voltage gated Na channels

27

phenytoin metabolism

- IV or PO, PO bad in children
- inducer
- zero order kinetics at high doses due to enzyme saturation
- half life 6-24hrs
- hepatic metabolism

28

phenytoin toxicity

- gingival hyperplasia
- ataxia
- osteomalacia

29

benzo used for

- everything
- especially status epilepticus, alcohol seizure and withdrawal
- sedative and anxiolytic

30

benzo mechanism

GABA agonist

31

benzo metabolism

- PO or IV
- hepatic
- non-inducer

32

benzo toxicity

sedation, depression, withdrawal seizures

33

carbamazepine use

- good for focal and secondary
- mood stabilizer
- NOT a benzo

34

carbamazepine mech

Na blocker

35

carbamazepine metabolism

- oral only
- half life 12 hours
- hepatic
- inducer
- levels increased by Ca blockers and microlide antibiotics

36

carbamazepine toxicity

Blurred vision, sedation, neutropenia, hyponatremia, weight gain.

37

ethosuximide use

only for absence

38

ethosuximide mech

blocks T-type Ca channels

39

ethosuximide metabolism

- oral only
- good GI absorption
- half life 24-48hrs
- hepatic
- mild inducer

40

ethosuximide toxicity

- GI distress
- sedation
- behavioral

41

valproate use

- all seizures
- migraine
- bipolar disorder

42

valproate mech

not well understood, Na? Ca? K? GABA?

43

valproate metabolism

- PO or IV
- half life 15 hours
- hepatic
- non-inducer

44

valproate toxicity

- GI upset,
- weight gain
- menstrual problems
- hair loss
- low platelet count
- hepatic encephalopathy sometimes but not always associated with elevated ammonia levels and carnitine deficiency

45

gabapentin use

- focal and secondarily generalized seizures
- anxiolytic
- sedative
- anti-spasmodic

46

gabapentin mech

- increases GABA levels in brain
- may block Ca channels

47

gabapentin metabolism

- oral only
- half life 6 hours
- not in urine
- not inducer
- well absorbed

48

gabapentin toxicity

- sedation, especially in elderly
- pedal edema
- GI distress

49

lamotrigine use

- all seizures
- bipolar
- neuropathic pain

50

lamotrigine mech

- blocks glutamate release presynaptically
- blocks Na channels post synaptically

51

lamotrigine metabolism

- oral
- non-inducer
- hepatic metabolism and renal excretion
- half life 24 hours

52

lamotrigine toxicity

allergic rash

53

topiramate use

- broad, not good for absence
- migraine
- neuropathic pain

54

topiramate mech

- Na blockade
- GABA agonist
- glutamate antagonist

55

topiramate metabolism

- oral
- non-inducer
- half life 24 hours
- some hepatic metabolism, mostly renal clearance unchanged

56

topiramate toxicity

- sedation
- aphasia
- parasthesias
- kidney stones

57

levetiracetam use

- broad spectrum
- favorite in hospitals

58

levetiracetam mech

- Ca channels
- affects SV2 protein that allows vesicles to release NT

59

levetiracetam metabolism

- 2/3 renal unchanged
- not inducer
- not protein bound
- some hepatic metabolism to inactive metabolites

60

levetiracetam toxicity

cognitive and behavioral problems

61

what is the most effective AED for generalized epilepsy?

valproate

62

2 best drugs for child bearing women?

lamotrigine, levetiracetam

63

most effective drug for localized epilepsy?

- carbamazepine
- lamotrigine and levetiracetam tie for second