Epilepsy + Anti Epileptic Drugs Flashcards
What is the key excitatory neurotransmitter?
What receptor in involved?
Glutamate
NMDA receptor
What is the key inhibitor neurotransmitter?
What receptor in involved?
GABA
Via GABAA/B receptors
What is a seizure?
Clinical manifestation of abnormal excessive excitation + synchronisation of a group of neurones within the brain
What determines how a seizure presents?
Where uncontrolled signalling occurs (can be anywhere in brain)
What is an epileptic seizure?
A transient occurrence of signs and/or symptoms due to abnormal excessive or synchoronous neuronal activity in the brain
What is epilepsy?
A disorder of the brain characterised by a predisposition to generate epileptic seizures unprovoked by a systemic or neurological insult
Risk factors of epilepsy
- premature birth
- complicated febrile seizure
- head trauma, infection or tumour
- cerebrovascular disease
- dementia + neurodegenerative disorders
Define prodrome
Early signs or symptoms a seizure may be coming hours to days before
What does the term ictal mean?
During a seizure
What does the term interictal mean?
Between seizures
What does the term post ictal mean?
After seizure subsides
What class of drug is carbamazepine?
Sodium channel blocker
What are uses of carbamazepine?
Epilepsy
Trigeminal neuralgia
What is the mechanism of action of carbamazepine?
Sodium channel blocker
- blocks VGNC in excitatory neurone
- reduces Ca2+ influx + glutamate release
what are adverse drug reactions of carbamazepine?
- dizziness
- skin ash
- eosinophilia
- leukopenia
- hyponatraemia
What are important drug drug interactions of carbamazepine?
- reduces COCP effect
- increases warfarin metabolism
- CYP3A4 inhibitors e.g.clarithryomycin + diltiazem increase [carbamazeipine]
Why should carbamazepine not been given during pregnancy?
Teratogenic
- Neural tube defects
- Bone marrow depression
- AV conduction issues
What is the mechanism of action of phenytoin?
Sodium channel blocker
- blocks VGNC in excitatory neurone
- reduces Ca2+ influx + glutamate
What are adverse drug reactions of phenytoin?
- dizziness
- skin rash
- visual disturbances
- arrhythmia
- gingival hyperplasia
What is gingival hyperplasia?
Overgrowth of gums
Classifications of sezuires
Focal onset
Generalised onset
Unknown onset
What is a tonic clonic seizure?
Typical epileptic fit
- tonic stage: loss of consciousness, stiff body
- clonic stage: limbs jerk, possible loss of bladder/bowel control
What is an absence seizure?
Loss of awareness of surroundings
- staring blankly into space
- looks like daydreaming
- slight jerking of body
- unable to remember them
What is a clonic seizure?
Body shakes + jerks but does not go stiff at start
What is a tonic seizure?
Body muscles become stiff
What is a atonic seizure?
All muscles suddenly relax
What class of drug is sodium valproate?
Anticonvulsant
Uses of sodium valproate
Most types of epilepsy