Epilepsy Drugs Flashcards Preview

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Flashcards in Epilepsy Drugs Deck (35):
1

What are the four main pillars of epilepsy treatment?

Drugs, Diet, surgery, vagal stimulation

2

Define Anticolvulsant Hypersensitivity syndrome.

Life threatening ADR may occur in the first 1-8 weeks of epilepsy treatment
Fever
Rash
Viceral involvement (often liver)

3

What is the occurrence rate of AHS? what population has the highest risk?

1/1000,1/10,000

Most commonly Han Chinese

4

What class of drugs causes AHS?

Aromatic drugs:
phenobarbital, phenytoin, carbamazepine, lamotrigine

5

Deine refractory/intractable patients. What portion of patients achieve seizure freedom?

2/3 are drug responsive and will never get a seizure
1/3 never achieve drug control --> refractory

6

How do you know if a patient is intractable? refractory?

if they dont respond to an appropriate dose of a drug--> probably intractable
appropriate dose of 2 drugs--> definitely refractory

7

What kinds of seizures are intractable?

Complex partial seizures (also most common in adults)
West's and Lennox-Gastaut syndromes seizures

8

What are common comorbidities with epilepsy?

depression, anxiety, and suicide risk (3x)

9

What are common side effects with AED? Is abuse an issue?

Sedation, and stomach upsets
compliance is an issue, abuse is NOT

10

Is polypharmacy attempted in epilepsy?

Yes if the seizures are intractable
New compounds with few drug interactions have reawakened interest in rational polypharmacy

11

What is the effect of valproate on other drugs?

It increases blood levels of other drugs

12

What are the effects of phenobarbital, phenytoin, and carbamazepine on blood levels of other drugs?

They decrease blood levels of other drugs

13

What class of drugs affect birth control pills?

Inducer drugs, which are the amine groups drugs: phenobarbital, carbamazepine, phenytoin, and lamotrigine

14

What AED interacts with warfarin?

phenytoin

15

what are blood levels of the drug used for?

determine if concentrations are in therapeutic range, occurrence of ADRs in liver, kidneys or blood
noncompliance

16

How does withdrawal of AED happen?

Withdrawal should never be done quickly
risk for rebound seizures or status epilepticus
risk for losing driver's license if rebound seizure occurs

17

How does pregnancy affect treatment?

one drug is continued
Risk of seizures on the baby is higher than risks related to treatment

18

What is the teratogenic effect of AED during pregnancy?

Risk of teratogenicity increases with increased number of drugs
Phenytoin and valproate have the highest risk

19

What are the three mechanisms of AED action?

1- inhibition of voltage dependent Na channels
2- enhancing the activity of gaba-a receptor
3- inhibition of T voltage dependent Ca channels

20

What is the function of Na channel and what drugs inhibit it?

initiates action potentials
cycles between active, inactive, and resting states.

phenytoin and carbamazepine hold the channel a little longer in its inactive state--> lengthen the refractory period.

21

What drugs enhance the activity of gaba-a? how does this reduce seizures

barbituates and benzodiazepines
- increase gaba-a mediated Cl influx--> maintaining the membrane near its resting potential and reducing excitability

22

What is the risk associated with gaba-a mediating drugs?

sedation
paradoxical irritability especially in children

23

What drugs inhibit T type voltage gated Ca channels and what type of seizures are they used for?

Ethosuximide
these channels are highly important in the thalamus function--> absence seizures

24

What are rare side effects of ethosuximide?

Photophobia and hiccups

25

What drugs are used only for tonic-clonic and partial seizures?

Phenobarbital
Phenytoin
carbamazepine
levetiracetam

26

What patient population is phenobarbital used in?

Children (Partial seizures and tonic-clonic seizures)

27

What are some side effects of phenytoin?

Gingival heprplasia, hirsutism, acne
becomes zero order metabolism at therapeutic levels --> half life becomes larger
Nystagmus, ataxia

28

What patient population is phenytoin used in?

It is well tolerate in elderly patients

29

What is the mechanism of action of levetiracetam? and what is the associated risk of drug interaction

Decrease transmitter release (SV 2A binding)
very few drug interactions

30

What drugs are used as broad spectrum drugs to reduce seizures? what kind of seizures do they act on?

Tonic clonic, absence, and partial

Valproate, clobazam, lamotrigrine, topiramate.

31

What are the side effects of valproate?

Hairloss, tremor, weight gain, bruising, and bleeding
Hepatitis especially in young children
highly teratogenic

32

What class of drugs is clobazam? what's the associated risk of using it?

Benzodiazepine --> gaba-a
Sedation, personality change
dependence after 6 months

33

What is the risk of using lamotrigine?

Some patients show a rash that develops to hypersensitivity syndrome

34

What are the side effects of topiramate?

Sedation
Weight loss

35

What drugs are used IV? what for?

Status epilepticus
Benzodiazepines (lorzepam, diazepam, midazolam)
Phenytoin
Propofol, phenobarbital, pentobarbital
Full sedation if nothing works