Fitzy Pharm Seizures And Epilepsy Flashcards

1
Q

What drugs will treat absence seizures?

A

Ethosuxamide and valproic acid

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2
Q

Myoclonic clinic seizures

A

Benzodiazepines, clonazepam

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3
Q

Tonic clinic seizures

A

Narrow spectrum drugs: phenytoin and phenobarbital

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4
Q

Simple and complex seizures

A

Gabapentin, pregabalin, oxcarbamazepine, lacosamide, tiagabin, visabatrin, exogamous

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5
Q

Tonic clonic partial onset seizures

A

Narrow spectrum drugs: carbamazepine, phenytoin, phenobarbital
*cbz is only with partial onset seizures

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6
Q

What are the broad spectrum AED’s?

A

The treat generalized or partial onset seizures: Very low table lacks zest

  • valproic acid
  • lamotrigine
  • topic image
  • levetiracetam,
  • zonisamide.
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7
Q

Which AED’s will prolong the fast inactivation state of Na channels?

A

Lamotrigine and oxcarbamazepine

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8
Q

Which AED enhances slow inactivation?

A

Lacosamide

*important because of different mechanism

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9
Q

Which AED is slightly lipophilic?

A

Lamotrigine

* it just kinda sneaks to that internal binding site so it’s not as use-dependent as the other ones

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10
Q

Why do Na channel blockers act preferentially at the sites of epilepsy

A

They have the highest frequency of being open so the drug can bind to it!

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11
Q

Which drug is more effective in blocking high frequency firing? Phenytoin or carbamazepine?

A

Carbamazepine

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12
Q

What makes lamotrigine different from phenytoin or carbamazepine?

A

It also acts on other things like n and p type voltage gated calcium channels in the cortical neurons and neocortical potassium currents

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13
Q

What does lacosamide stabilize?

A

The slow inactivated state… The one where everything is totally shut
-works best when the stimulus was prolonged for tens of seconds

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14
Q

What kind of channels mediate absence seizures?

A

T-type calcium channels

*the 3 Hz spike is the dead giveaway

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15
Q

So, what drugs can be used to treat absence seizures?

A

-antagonists of t-type calcium channels
-narrow spectrum : ETHOSUXAMIDE
It sux because it’s only used for absence seizures and only limits excitation ….. And it’s non-sedating which sux as well

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16
Q

Valproate

A
  • 1st line for generalized onset seizures

- has intolerable adverse effects—- weight gain, hair loss, lethargy

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17
Q

Lamotrigine

A

Gets the Na v channels like cbz and phenytoin

-BUT it also acts at n and p type calcium channels in cortical neurons and neocortical potassium currents

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18
Q

Zonisamide

A
  • sulfanilamide derivative

- blocks Nav channels and t-type calcium channels

19
Q

What drugs will enhance the post-synaptic GABAergic neuronal transmission?

A
  • phenobarbital and related barbiturates
  • primidone…. Active metabolite is phenobarbital
  • benzodiazepines (diazepam and lorazepam and friends)
20
Q

What are phenobarbital’s complications?

A

Can cause significant sedation

  • lethal respiratory depression
  • has abuse and addiction potential
  • these suck, so benzodiazepines were made*
21
Q

How do benzodiazepines work?

A

Bind to distinct site… Aldosterone potentiation… GABA binds… There ya go….channel opens with greater FREQUENCY

22
Q

How does phenobarbital work?

A

Binds to distinct site on GABA receptor,

-increases the duration of the Cl- channel opening

23
Q

Why is the lethality of phenobarbital so much higher than benzodiazepine?

A

High douses of barbiturates are GABA independent

24
Q

What drugs are used to manage status epilepticus?

A

Diazepam or lorazepam with Fosphenytoin if needed

25
Q

What is clonazepam very effective at treating?

A

The emergency treatment of status epilepticus

26
Q

What actions does topirimate have?

A

Glutamate receptor antagonist, no depolarization there

GABA receptor agonist… Let’s in Cl- and then hyperpolarization happens

27
Q

MOA of Gabapentine

A

Binds to voltage dependent Calcium channels

-NO significant drug interactions

28
Q

MOA of leviteracetam

A

Binds to synaptic vehicle ptn SV2A- blunts glutamate release

-well tolerated…. NO CYP INTERACTION WHICH IS NICE

29
Q

Pregabalin MOA

A

Multiple…. 100% renal clearance so make sure their fucking kidneys work

30
Q

Ezogabine MOA

A

Opens voltage gated potassium channels and causes urinary retention

31
Q

What are the 4 pharmacokinetic properties?

A

ADME

  • absorption
  • distribution
  • metabolism
  • elimination
32
Q

Which drug has zero order kinetics?

A

Phenytoin

  • so doubling dose does not necessarily double serum level
  • dose adjustment is very difficult
33
Q

What are some complications with phenytoin?

A

Induce of hepatic cyp450n enzymes

  • gingival hyperplasia
  • hirsuitism
  • hypocalcemia
  • osteoporosis
34
Q

What are some complications with carbamazepine?

A

Inducer of hepatic cyp450 enzymes

  • aplastic anemia
  • leukopenia, neutropenia, thrombocytopenia
  • hypocalcemia, osteoporosis
35
Q

Why is the induction of CYP450 such a big deal?

A

When carbamazepine induces it,

  • creates the inactive form of vitamin D
  • osteopenia/osteoporosis
  • less vit D, less Ca2+ absorption in intestin
  • trigger compensatory PTH -mediated responses that demineralization bone
36
Q

how do AED’s mess with oral contraceptives?

A

Starting cbz can increase the clearance of oral contraceptives metabolized by CYP isoenzymes….

  • 4 fold rise in OCP failure rate
  • risk for unplanned pregnancy
37
Q

How do AED’s mess with oral anticoagulants?

A

Increase the clearance of warfarin metabolized by,…. You guessed it.. CYP isoenzymes
-too rapid coagulation…. High risk for AV thrombosis

38
Q

What analogue of cbz has fewer side effects because of lack of formation of an active metabolite?

A

Oxcarbazepine

39
Q

Which two AED’s have 100% renal clearance?

A

Gabapentine
Pregabalin
-renal insufficiency requires dose adjustment

40
Q

What are the adverse effects of OXCBZ

A

Hyponatremia and rash… More common in elderly

41
Q

Adverse effects of tiagabine

A

Stupor

42
Q

Adverse effects of topirimate

A

Nephrolithiasis, open angle glaucoma, hypohidrosis, in children

43
Q

Adverse effects of zonisamide

A

Rash, renal calculus, hypohidrosis (mainly children)