Anticonvulsants II Flashcards Preview

Year 2 Pharmacology > Anticonvulsants II > Flashcards

Flashcards in Anticonvulsants II Deck (47):
1

what are the hydantoin antiseizure drugs?

phenytoin and fosphenytoin

2

which hydantoin antiseizure drug is more soluble and used for parenteral use?

fosphenytoin

3

where is phenytoin metabolized? by what system?

liver - MES system

4

how is phenytoin excreted?

urine

5

elimination of phenytoin follows what kinetics?

dose-dependent (zero order)

6

what is the MOA of phenytoin?

1. blocks and prolongs inactivated state of voltage gated sodium channels
2. enhances release of GABA
3. prevents seizure progagation

7

what are the clinical uses for phenytoin?

generalized tonic-clonic, partial, status epilepticus

8

what are the dose related side effects of phenytoin?

sedation, ataxia, nystagmus, diplopia, cardiac dysrhythmias

9

what are the idiosyncratic side effects of phenytoin?

gingival hyperplasia

10

which drug interactions decrease phenytoin metabolism?

barbiturates (high), warfarin

11

which drug interactions increase phenytoin metabolism?

barbiturates (low), carbamazepine

12

which drug interactions displace the protein binding of phenytoin?

salicylates, valproic acid, kidney failure

13

which drug class is carbamazepine?

tricyclic

14

what is the MOA of carbamazepine?

inhibition of voltage gated sodium channels (same as phenytoin)

blocks high frequency firing of neurons and decreases synaptic release of glutamate

15

what is oxacarbazepine?

antiseizure drug similar to carbamazepine - shorter half life but active metabolite has longer duration and fewer drug interactions

16

what are the clinical uses of carbamazepine?

general clonic-tonic (grand mal), partial seizures, TRIGEMINAL NEURALGIA

17

how is carbamazepine metabolized?

hepatic MES - induces p450s to upregulate its own metabolism

18

what is the drug of choice for trigeminal neuralgia?

carbamazepine

19

carbamazepine has drug interactions with which other drugs?

phenytoin, valproate, phenobarbital

20

what is the MOA of the phenobarbital?

enhances phasic GABAa receptor responses - increased opening time of chloride channel

21

what are the side effects of cabamazepine?

syndrome of inappropriate ADH secretion - fluid retention and hyponatremia

22

what is the main clinical use for phenobarbital?

status epilepticus

23

what is primidone?

metabolized by liver (MES) to phenobarbital and phenyl ethyl malonic acid (PEMA)

24

what is the MOA of ethosuximide?

blocks presynaptic T type calcium channels (blocks high frequency firing of neurons)

25

what are the clinical uses for ethosuximide?

absence seizures (petit mal)

26

what are the drugs of choice for petit mal (absence) seizures?

ethosuximide, valproic acid

27

what is the MOA of valproic acid?

1. inhibition of presynaptic T type calcium channels - blocks neuronal firign
2. inhibition of GABA transaminase

28

what is the main clinical use of vvalproic acid?

absence (petit mal) seizures

29

what is the main adverse event of valproic acid?

hepatotoxic syndrome, teratogenic risk

30

what are the preferred initial agents for status epilepticus?

diazepam (valium) or lorazepam (longer acting)

31

what is the MOA of diazepam?

potentiates GABAa responses by increasing frequency of channel opening

32

what is the main clinical use of diazepam?

status epilepticus

33

what are the use limitations of diazepam?

1. sedative
2. tolerance

34

which drugs apart from diazepam and lorazepam can be used as antiepilepsy drugs?

clonazepam, nitrazepam, clorazepate

35

what is the MOA of gabapentin?

blocks presynaptic voltage gated calcium channels - decreaes excitatory transmission

36

what are the clinical uses for gabapentin?

1. generalied tonic-clonic (grand mal)
2. partial seizures
3. ****neuropathic pain - postherpetic neuralgia and fibromyalgia****

37

what is pregabalin?

similar to gabapentin, GABA analog

38

what is the MOA of lamotrigine?

blocks presynaptic voltage gated sodium and calcium channels

39

what are the clinical uses for lamotrigine?

1. partial
2. grand mal
3. petit mal

40

what is the main adverse effect of lamotrigine?

steven johnson syndrome - severe blistering / necrosis of skin

41

what are the "other" newer agents of anticonvulsants?

1. felbamate
2. topiramate
3. tiagabine

42

definition: spasticity

exaggerated muscle stretch reflex syndrome that occurs following injury to CNS

43

definition: spasm

increase in muscle tension seen after certain musculoskeletal injuries and inflammation

44

what is the MOA of diazepam as a muscle relaxant?

increases inhibitory actions of GABA on alpha motor neurons in spinal cord

45

what is the MOA of baclofen as a muscle relaxant?

GABAb receptor agonist - increased potassium conductance, hyperpolarization, reduction in calcium influx, reduction in excitatory transmitter release

46

which drug treats spasms associated with excess exertion, MS, cerebral palsy, injury?

diazepam

47

which drug reduces spasticity with MS, spinal, and brain injury?

baclofen

Decks in Year 2 Pharmacology Class (70):