Antiepileptic Drugs Flashcards Preview

Pharmacology > Antiepileptic Drugs > Flashcards

Flashcards in Antiepileptic Drugs Deck (18):
1

what are seizures

the clinical expression of abnormal, hyper synchronous brain activity
-manifestations reflect the function of the brain area involved
-may include impairment of cognition or consciousness, involuntary movements, behavioural automatisms, and sensory, psychic or autonomic functions

2

what are epilepsies and epileptic syndromes

-spontaneous recurrent seizures
-characterized by a clustering of signs and symptoms that regularly occur together

3

seizure classification

1. partial seizures (focal): simple and complex partial
2. partial seizures evolving to secondarily generalized seizures

4

pathophysiology

-focal epileptogenesis
-synchronization
-propagation

5

actions of anti epileptic drugs

-voltage and frequency dependent blockade of Na channels; slow recovery from inactivation; blockade of sustained, high-frequency AP
-potential GABA-mediated neuronal inhibition
-inhibit low threshold, Ca++ (T) currents in thalamic neurone
-inhibit excitatory a.a neurotransmitter release
-inhibit glutamate NMDA receptor

6

when does therapy begin

after 2 or more seizures

7

how do you monitor the effectiveness of the drugs

monitor plasma concetrations

8

what drugs are used to treat status epilepticus

1. Lorazepam or diazepam IV
2. phenytoin or phenobarbital
3. phenobarital or phenytoin
4. anesthetic

9

what are CNS AE

-sedation
-dizziness, blurred vision, diplopia
-cerebellar and brainstem dysfunction
-extrapyramidal dysfunction
-cognitive impairment

*dose-related CNS effects limit the dosage of most AEDs

10

what are dermatologic AE

-rashes ranging from mild to life-threatening

11

what are hematologic AE

-rxns secondary to altered folate metabolsim; coagulation defects; immune-mediated phenomena; bone marrow suppression

12

other AE

-hepatic (idiosyncratic)
-renal
-MSK
-decrease in bone mineral content
-CT disorders
-endocrine
-teratogenicity
-increase risk of suicidal thoughts and behaviours

13

AEDs (phenytoin, carbamazepine, phenobarbital, primidone) induce what

P-450 enzymes

14

what effect does valproate have on AEDs

inhibits metabolism of phenytoin, Iamotrigine, and carbamazepine

15

what effects do antimicrobials have on AEDs

macrolide Abs and azole antifunals may cause elevated levels of certain AEDs (carbamazepine, phenytoin, valproate, zonisamide)

16

what are the newer AEDs

-gabapentin, Iamotrigine, oxcarbazepine
-better tolerability but no substantial difference in efficacy

17

which new AEDs have been shown to have broad spectrum activity with efficacy against generalized, as well as partial onset seizures

Lamotrigine, topiramate, and zonisamide

18

most newer AEDs lack what

CYP induction and interactions w/ other hepatically metabolized medications