Epilepsy Pharm Flashcards
What is epilepsy
Enduring predisposition to generate epileptic seizures and associated cognitive , psychological and social consequences.
Abnormal excessive or synchronous electric discharges in the brain
Provoked vs Unprovoked Seizures
Provoked: Ex: take drugs which cause patient to have seizure , reversible risk factors
Unprovoked: no acutely reversible risk factor for the seizure ( structural or functional problem)
If you have 2 seizures within more than 24hrs then this means what
Patient is more likely to have more seizures later in life , think epilepsy
Can 1 seizure cause epilepsy ?
Yes
What is Resolution Epilepsy
If it’s an age dependent syndrome and patient has grown out of it
What is drug refractory epilepsy
Pharmacoresistant epilepsy
Considerations taken in when prescribing Anti-seizure Medication ( ASM ) for patient ?
1- Type ( focal/generalized ) 2- Spectrum or efficacy 3- Comorbidities ( migraine , bipolar ) 4- Tolerability ( compliance) 5- pharmacokinetics and dynamics 6- Speed of titration 7- Cost, blood tests , frequency of administration
What is the goal for medication for epilepsy patients
Patient to be seizure free without adverse effects
Classification of Seizure
1- Focal Onset - Aware / impaired awareness - motor onset - non motor onset - focal to bilateral tonic-clonic 2- Generalized onset - motor : tonic-clonic / the motor - non motor( absence ) 3- Unknown onset - tonic-clonic / other motor - non motor
What is a focal onset seizure ?
Seizure that starts in one area of the brain
Symptoms of focal onset seizure in Limbic region
- Changes in taste , smell
- funny feeling in epigastrium
- memory disturbance
- psychiatric dysfunction ( extreme fear / goosebumps )
What is a Generalized Onset Seizure
Seizure that has a widespread disturbance of brain function
If patient has seizure in the inferior frontal lobe, what symptoms will they present with
Speech disturbance
What cell stages are targeted by anti-epileptic medications
1- Sodium channels on presynaptic area that release neurotransmitters
2- GABAa receptors : GABA causes CL- to rush in , inactivating neurone
3- NMDA/AMPA receptors that block glutamate from binging to receptors and causing excitation
4-
What is the key excitatory and inhibitory neurotransmitter for neuronal transmission
Excitatory : glutamate
Inhibitory : GABA
Which Anti-seizure medications promote inhibition
1- Topiramate
2- Benzodiazepines
3- Valproate
Which Anti-seizure medications reduce excitation
1- Phenytoin 2- Carbamazepine 3- Lamotrigine 4- Valproate 5- Topiramate 6- Levetiracetam
Which Anti-seizure medications are the sodium channel blocking drugs
Carbamazepine and Phenytoin
Which seizures should Carbamazepine and Phenytoin not be used for
Absence and Myoclonic
If someone presents with focal or generalized seizures which medication will be chosen and why ?
Drugs with least interactions , side affects and with priority to comorbidities. Could be used for all seizure types
Lamotrigine or Levetiracetam
Which ASM is most affective for generalised seizures, but why is it not the one always used
Sodium Valproate but it’s side effects , especially for women make it not possible to prescribe sometimes
Explain Carbamazepine , MOA , side effects , interactions
MOA : sodium channel blocker
Hepatically metabolized
Interactions: Strong hepatic enzyme inducer ( CYP3A4 ) - messes up a lot of medications
- auto-induction of liver enzymes : liver gets better at metabolizing carbamazepine the more it’s used = need to increase dose later
- bone health , can metabolize vitamin D more rapidly
- Abnormal lipid function & CVS risk
Side effect :
- reduces liver function
- dizziness, headaches, double vision
- fatigue , nausea , GI disturbance
- Hyponatraemia through SIAH mechanism
- Idiosyncratic : bone marrow suppression , hypersensitivity , hepatic derangement , rash
Explain Phenytoin , MOA , side effects , interactions
MOA: Sodium channel blockers
Side effects :
Acute : dizziness, ataxia , fatigue , diplopia , nystagmus, rash , sedation
Chronic: gum hyperplasia, coarse face, hirsutism, osteopenia, enhanced Vitamin D metabolism , low folate, peripheral neuropathy
Idiosyncratic: fever, rash , lymphadenopathy, teratogenic
Interactions : Hepatic enzyme induced = reacts with most drugs
Which contraceptive is not effective while on Carbamazepine
Progesterone
