21) Anti-Epileptic Drugs Flashcards Preview

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Flashcards in 21) Anti-Epileptic Drugs Deck (28)
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1
Q

What is epilepsy?

A

Episodic discharge of abnormal high frequency electrical activity in brain leading to seizure

2
Q

How can a diagnosis of epilepsy be determined?

A

Evidence of recurrent seizures, unprovoked by identifiable causes

3
Q

How are seizures classified?

A

Partial (simple and complex)

Generalised

4
Q

What are some dangers of severe epilepsy?

A

Physical injury
Hypoxia
SUDEP
Brain dysfunction

5
Q

What is primary epilepsy?

A

No identifiable cuase

6
Q

What is secondary epilepsy?

A

Medical condition affecting the brain e.g. vascular disease or tumour

7
Q

What are some precipitants to epilepsy?

A
Sensory stimuli
Brain disease/trauma
Metabolic - hypoglycemia, hypocalcemia, hyponatremia
Infections 
Therapeutics
8
Q

What are the targets of anti-epileptic drugs?

A

Voltage gated sodium channel blockers
Enhancement of GABA
Inhibition of Ca2+ channel function
Inhibition of glutamate

9
Q

What are some examples of drugs that prolong VG sodium channel inactivation state?

A

Carbamezepine
Phenytoin
Lamotrigine

10
Q

For what types of seizures is carbamezepine indicated?

A

Tonic clonic

Partial

11
Q

What are the side effects of carbamezepine?

A

Dizziness, ataxia, numbness, rashes, hyponatremia, motor disturbance
Rare: neutropenia

12
Q

For what types of seizures is phenytoin indicated?

A

Tonic clonic

Partial

13
Q

What are the side effects of phenytoin?

A

Dizziness, ataxia, headache, nystagmus, gingival hyperplasia. Stevens-Johnson

14
Q

How is phenytoin monitored?

A

Monitor free concentration in plasma

Salivary levels

15
Q

For what types of seizures is lamotrigine indicated?

A

Partial
Tonic clonic
Absence

16
Q

What are the side effects of lamotrigine?

A

Dizziness, ataxia, sleepiness, nausea, skin rashes

17
Q

Why does enhancing GABA help in treating seizures?

A

Post synaptic inhibition and a natural anti-convulsant

18
Q

What is the mechanism of action of valproate?

A

Inhibits GABA inactivation, stimulates GABA synthesis, VGSCB

19
Q

What are the side effects of valproate?

A

Sedation, ataxia, tremor, weight gain

Rare: hepatic failure

20
Q

For what types of seizures is valproate indicated?

A

Partail, tonic clonic and absence

21
Q

What are the side effects of benzodiazepines?

A

Sedation, tolerance, confusion, aggression, withdrawal, resp and CNS depression

22
Q

How is benzodiazepine overdose treated?

A

IV flumazenil

23
Q

Give examples of benzodiazepines:

A

Lorazepam/diazepam - status epilepticus

Clonazepam - absence

24
Q

How can anti-epileptic drugs affect the fetus?

A

Congenital malformations
Facial and digit hypoplasia
Neural tube defects (valproate)

25
Q

How do anti-epileptic drugs affect contraception?

A

Failure rate of contraception is 4x as high when using carbamazepine or phenytoin

26
Q

How should anti-epileptics be used in pregnancy?

A

Single agent at lowest dose
Use lamotrigine
High dose folate supplements and vit K (trimester 3)

27
Q

What is status epilepticus?

A

Prolonged seizure of any type - single convulsion lasting more than 30 mins or convulsions back to back with no recovery

28
Q

What is the treatment for status epilepticus?

A

ABCDE, O2, terminate seizure
Lorazepam IV
IV phenytoin
If no response - midazolam, propofol and ITU admission