AEDs

Question 1

Know the general classification of epilepsy based on partial and generalised seizures

Answer 1

Partial/Focal –> simple (conscious)/complex (unconscious)

Generalised –> aclonic/myoclonic/tonic-clonic/absence

Question 2

Understand the difference between primary and secondary causes of epilepsy

Answer 2

Primary - idiopathic

Secondary - vascular disease, tumours etc.

Question 3

Describe some of the major recognised precipitants of epilepsy

Answer 3

Sensory
Brain disease/trauma
Metabolic disturbances
Infections
Therapeutics

Question 4

Understand the broad models of how epilepsy is generated within the brain

Answer 4

Increased excitatory or decreased inhibitory –> loss of homeostatic control –> spread of neuronal hyperactivity

Question 5

Appreciate that untreated epilepsy can be a life threatening condition

Answer 5

Physical injury
Hypoxia
SUDEP
Brain dysfunction/damage
Cognitive impairment
Psychiatric disease

Question 6

Describe the method of action, ADRs and DDIs of carbamazepine

Answer 6

MOA - prolongs VGSC inactivation, affects own phase 1 metabolism
ADRs - dizziness, drowsy, ataxia, motor disturbances, numbness, neutropenia
DDIs - phenytoin, warfarin, COCP, antidepressants

Question 7

Describe the method of action, ADRs and DDIs of phenytoin

Answer 7

Blocks voltage gated sodium channels
Non linear kinetics, CYP450 inducer
ADRs - CNS, gingival hyperplasia, rash, Stevens Johnsons syndrome
DDIs - valproate, NSAIDs, COCP

Question 8

Describe the method of action, ADRs and DDIs of lamotrigine

Answer 8

Blocks voltage gated sodium channel, calcium channel blocker? Lowers glutamate? 
Linear kinetics, no CYP450 induction 
ADRs - CNS, nausea, rash
DDIs - valproate, COCP 
*safe in pregnancy

Question 9

Describe the method of action, ADRs and DDIs of sodium valproate

Answer 9

Inhibits GABA inactivation enzymes, stimulates GABA synthesis enzymes, linear kinetics
ADRs - CNS, weight gain, liver damage
DDIs - antidepressants, antipsychotics, aspirin
*not safe in pregnancy –> causes neural tube defects, congenital malformations (therefore take folate, vitamin K)

Question 10

Describe the method of action, ADRs and DDIs of benzodiazepine

Answer 10

Positive allosteric modulator, increases total conduction of chloride ions
ADRs - dizziness, drowsiness, withdrawal, tolerance, seizure trigger, respiratory and CNS depression
DDIs - COCP, antidepressants, antifungals carbamazepine, phenytoin

Question 11

Describe the safety concerns of anticonvulsant therapy in pregnancy

Answer 11

Ensure anti-epileptic is not a teratogen (NOT valproate, only lamotrigine is safe)
Monitor for pre-eclampsia/eclampsia

Question 12

Appreciate the value of therapeutic drug monitoring in phenytoin therapy

Answer 12

Phenytoin has non-linear kinetics so monitoring is very important to prevent toxicity

Question 13

Differentiate between the terms ‘seizures’, ‘epilepsy’ and ‘status epilepticus’

Answer 13

Seizures - episodic discharge of abnormal high frequency electrical activity in the brain, clinical manifestation of abnormal and excessive excitation and synchronisation of population of cortical neurons
Epilepsy - >2 unprovoked episodes
Status Epilepticus - seizure >5 minutes or fits following one another without recovery of consciousness between them

Question 14

Describe the dietary supplements needed during pregnancy

Answer 14

Folate - reduce risk of neural tube defects
Vitamin K (10mg/day in last trimester) - prevent coagulopathy and cerebral haemorrhage in new born

Question 15

Describe the treatment of status epilepticus

Answer 15

Benzodiazepine (IV/PR lorazepam)
IV phenytoin
Midazolam/Pentobarbital/Propofol
–> ITU for paralysis/ventilation if failing