12. Epilepsy And Antiepileptic Drugs Flashcards

1
Q

What is a seizure?

A

Transient occurrence of signs or symptoms due to abnormal electrical activity in the brain, leading to disturbance of consciousness, behaviour, emotion, motor function or sensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what can cause an imbalance in inhibitory and excitatory receptors?

A

Genetic differences in brain chemistry/receptor structure (epilepsy)
By exogenous activation of receptors (drugs)
Acquired changes in brain chemistry (drug withdrawal)
Damage to any of these networks (stroke, tumours)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the signs and symptoms of a seizure?

A

Loss of consciousness with changes in muscle tone, tongue biting
Initial hypertonic phase, followed by rapid clonus of the limbs
Post-ictal period present
Often an aura prior to seizure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What can bring on a reflex seizure?

A
Photogenic
Musicogenic
Thinking
Eating
Hot water immersion
Reading
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 3 types of seizures?

A

Focal onset
Generalised onset
Unknown onset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What can cause provoked seizures?

A
Drug use or withdrawal
Alcohol withdrawal
Head trauma and intracranial bleeding
Metabolic disturbances
CNS infections
Febrile seizures in infants
Uncontrolled hypertension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is status epilepticus?

A

A seizure lasting more tan 5 minutes or more, or multiple seizures without a complete recovery between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the pharmacological treatment for status epilepticus?

A

0-5mins - full dose of benzodiazepine
0-15mins - 2nd full dose of benzodiazepine
15-45mins - 2nd line antiepileptic (phenytoin/levetiracetam)
45+ mins - thiopentone/anaesthesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the class of benzodiazepine?

A

GABAa agonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the action of benzodiazepines?

A

Increase Cl- conductance = more negative resting potential, less likely to fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the benzodiazepine options for status epilepticus?

A

IV lorazepam
Diazepam rectally
Buccaneers or intranasal midazolam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the investigations for epilepsy?

A

Electroencephalography

MRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What class of drug is carbamazepine?

A

Sodium channel blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the side effects of carbamazepine?

A

Suicidal thoughts
Joint pain
Bone marrow failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What class of drug is phenytoin?

A

Sodium channel blocker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When is phenytoin mainly used?

A

Status epilepticus

Or as an adjunct in generalised seizures

17
Q

What are the side effects of phenytoin?

A

Bone marrow suppression
Hypotension
Arrhythmias

18
Q

What are the actions of sodium valproate?

A

Mix of GABAa effects and sodium channel blockade

19
Q

What are the side effects of sodium valproate?

A

Liver failure
Pancreatitis
Lethargy

20
Q

What is the first line drug for generalised epilepsies?

A

Sodium valproate

21
Q

Where does lamotrigine act?

A

Primarily sodium channel blocker

May also affect calcium channels

22
Q

What is lamotrigine good for?

A

Focal epilepsy

23
Q

What is the action of levetiracetam?

A

Synaptic vesicle glycoprotein binder, stops release of neurotransmitters into synapse and reduces neuronal activity

24
Q

Which antiepileptic drug is safe in pregnancy?

A

Levetiracetam

25
Q

What is levetiracetam used in?

A

Focal seizures and generalise seizures

26
Q

What are some general side effects of AEDs?

A
Tiredness/drowsiness
Nausea and vomiting
Mood changes and suicidal ideation
Osteoporosis 
Rashes - Steven Johnson syndrome
Can cause anaemia, thrombocytopenia or bone marrow failure
27
Q

Which patients need particular monitoring when on AEDs?

A

Those that are also on warfarin

28
Q

Which of the AEDs are CYP enzyme inducers?

A

Phenytoin
Carbamazepine
Barbituates

29
Q

Which of the AEDs is a CYP enzyme inhibitor?

A

Valproate

30
Q

Which AED should not be prescribed to any woman of childbearing age unless on pregnancy prevention programme?

A

Valproate