Antiepileptics Flashcards
Treatment for status epilepticus
0-5 mins = full dose benzodiazepine
0-15 mins = 2nd full dose benzodiazopene
15-45 mins = IV phenytoin or levetracetam (thiamine if alcohol use)
45+ mins = thiopentone/anasethesia (with support)
diazepam, lorazepam, midazolam
Indication: epilepsy
- seizure termination
- not a typical preventative drug
Class: benzodiazepine
Route:
- Intravenous Lorazepam
- Diazepam rectally
- Buccal or intranasal Midazolam – Don’t lose a finger
- IO or IM
Action:
- GABAa agonists
- increased cl- conductance - more negative resting potential
- no firing neurones, no seizure
Adverse effects:
- addiction
- cardiovascular collapse
- airway issues
- tiredness/drowsiness
- nausea and vomiting
- mood changes and suicidal ideation
- osteoporosis
Interactions: can cause a CNS depressant effect with other drugs - affect ability to perform skilled tasks e.g driving
Other: also used as anxiolytics, sleep aids, alcohol withdrawal
Carbamazepine (tegretol)
Indication: epilepsy
- preventative drug
Action:
- sodium channel blocker
- slows recovery of neurones from inactive to closed state
- reduces neuronal transmission
Adverse effects:
- suicidal thoughts
- joint pain
- bone marrow failure
- steven johnson syndrome
- tiredness/drowsiness
- nausea and vomiting
- mood changes and suicidal ideation
- osteoporosis
Interactions:
- decrease effectivness of some antibiotics
- decrease effectivenss of oral contraceptives
- induce CYPs
Other: also used in bipolar and chronic pain
Phenytoin
Indication: epilepsy
- status epilepticus
- adjunct in generalised seizures
Action:
- sodium channel blocker
- slows recovery of neurones from inactive to closed state
- reduces neuronal transmission
Adverse effects:
- bone marrow supression
- hypotension
- arrythmias (IV use)
- steven johnson syndrome
- tiredness/drowsiness
- nausea and vomiting
- mood changes and suicidal ideation
- osteoporosis
Interactions:
- decrease effectivness of some antibiotics
- decrease effectivenss of oral contraceptives
- induce CYPs
Other: exhibits zero order kinetics - care with adjusting dose
Sodium valproate
Indication: epilespy
- 1st line for generalised epilepsies
Action:
- GABAa effects - increased cl- conductance - more negative resting potential
- sodium channel blocker - slows recovery of neurones from inactive to closed state
Adverse effects:
- liver failure
- pancreatitis
- lethargy
- tiredness/drowsiness
- nausea and vomiting
- mood changes and suicidal ideation
- osteoporosis
Interactions:
- CYP inhibitor
- increase plasma conc of other AEDs
Other: highly tetarogenic - must be on the pregnancy prevention programme
Lamotrigine
Indication: epilepsy
- focal epilepsy
- generalised epilepsy where valproate contraindicated
- SAFER in pregnancy
Action:
- sodium channel blocker - slows recovery of neurones from inactive to closed state
- may also affect calcium channels
Side effects:
- tiredness/drowsiness
- nausea and vomiting
- mood changes and suicidal ideation
- osteoporosis
Levetiracetam
Indication: epilepsy
- focal or generalised
- being used more frequently (easy dosing and well tolerated)
- SAFER in pregnancy
Action:
- synpatic vesicle glycoprotein binder
- stops release of neurotransmitter into synapse
- reduces neuronal activity
Side effects:
- tiredness/drowsiness
- nausea and vomiting
- mood changes and suicidal ideation
- osteoporosis
