PHARM - Antiepileptic Drugs - Week 10 Flashcards
What percentage of the worlds population has epilepsy?
1%
What percentage of those with epilepsy have seizures?
8%
Is there a genetic link to epilepsy?
Yesd
Name 7 possible causes of epilepsy.
Fever
Brain tumour
Trauma
Abnormalities in CNS development
Infection
Stroke
Heredity
Name 7 precipitating factors for epilepsy.
Stress/anxiety
Sleep deprivation/fatigue
Hormonal changes associated with the menstrual cycle
Certain medications
Diabetes/blood sugar imbalances
Neon/xeon strobe flashes
Rapid motion
How can seizures be measured? What are they characterised by (2)?
Using electroencephalography - it has a sudden onset and is characterised by hyper-excitability and hyper-synchronised activity of large groups of neurons
What are epilepsy recurrent seizures due to?
Chronic underlying process
Name the two broad classifications of seizures and list two subtypes each.
Focal (partial)
-simple
-complex
Generalised
-tonic-clonic
-absence
Where do complex focal seizures arise from?
Temporal lobe
Is there a loss of consciousness in simple focal seizures?
No
List 4 broad treatment options for epilepsy and describe them if appropriate ().
Identify the underlying cause
Avoid precipitants (behavioural modification)
Anti-epileptic drugs
-palliative rather than curative
Surgery
What is the most common surgical approach to epilepsy?
Temporal lobe resection
Consider anti-epileptic drugs. Do patients respond well to a single drug?
33% do not respond to a single epileptic - polytherapy needed
What is the aim of antiepileptic drugs?
To inhibit abnormal neuronal discharge rather than correct the underlying cause
Can a synapse be both inhibitory and excitatory?
Yes, it can be one, the other, or both
Can a neurotransmitter be both excitatory and inhibitory?
Yesd like serotonin
What are two ways an anti-epileptic drug can work?
Reduce excitatory input
Enhance inhibitory input
Briefly describe how phenytoin works.
Limits excitatory nerve activation by blocking Na+ channels
List 3 mechanisms of action that an anti-epileptic drug can have.
Inhibit voltage-dependent Na+ channels
Inhibit voltage-dependent Ca2+ channels
Enhance GABA action
What channels are active in absence seizures? What Hz spike is seen in these seizures on an EEG?
T-type Ca2+ channels are active
Has a characteristic 3Hz spike ans wake pattern
What are three ways GABA action can be enhanced?
Allosteric modulation on the GABAa receptor
Inhibiting reuptake
Inhibit GABA transaminase
List 5 side effects of anti-epileptic drugs.
Sedation
Unsteadiness
Diplopia
Nausea
Increased fracture risk
What is very important during epilepsy therapy?
Patient compliance
