CNS epilepsy Flashcards
when prescribing anti-epileptics, what is the dosage frequency determined by
plasma-drug half-life,
should be kept as low as possible for adherence
most antiepileptics when used in normal dosage can be given BD.
which 4 antiepileptics have long t1/2 and can be given OD at bedtime
Lamotrigine
perampanel
phenobarbital
phenytoin
2 types of seizures
focal
generalised
what are focal seizures
pt doesn’t lose consciousness
but symptoms of genaralised seizures still occur
first and second line tx for FOCAL seizures
first: Lamotragine or Levetiracetam
(take 2 Ls to get focused)
second: carbamazepine, oxcarbazepine, or zonisamide (COZ)
types of GENERALISED SEIZURES? TAM
TONIC-CLONIC/ATONIC/TONIC
ABSENCE
MYOCLONIC
GENERALISED SEIZURES- 1st LINE & 2ND LINE
for TONIC-CLONIC/ATONIC/TONIC?
1) Sodium Valproate 2) Lamotrigine /
leve (unlicensed)
GENERALISED SEIZURES- 1st LINE & 2ND LINE
for ABSENCE?
1) Ethousixime or sodium valproate (valp if high risk of generalised tonic-clonic)
2) Lamotrigine
GENERALISED SEIZURES- 1st LINE & 2ND LINE
for MYOCLONIC (myoclonic jerks) ?
1) Sodium Valproate
2) Levetiracetam
what is status epilepticus?
seizure lasting longer than 5 minutes
how is status epilepticus treated?
IV lorazepam (if rescus facilities available)
buccal midazolam/ rectal diazepam (community)
give 2nd dose if seizure doesnt stop after 5-10mins of first dose
status epilepticus what to do if seizure fails to respond after 2 benzo doses?
PLS
levetiracetam [unlicensed use], phenytoin, or sodium valproate as second line
what to do if status epilepticus fails to respons after 2nd line?
phenobarbital/ general anaesthesia
category 1 anti-epileptics are MOST severe and must ensure pt maintained on specific brands!
give 4 examples of these drugs (CP3)
Carbamazepine
Phenobarbital
Phenytoin
Primidone
category 2 anti-epileptics - specific brands maintained based on clinical judgement
give examples (CL-VOP)
Clobazam
Clonazepam
Lamotrigine
Oxcarbazepine
Perampanel
Rufinamide
Topiramate
Valproate
Zonisamide
category 3 anti-epileptics - unnecessary to maintain specific brands
give examples (BEG-LePre)
Brivaracetam
Ethosuximide
Gabapentin
Lacosamide
Levetiracetam
Pregabalin
Tiagabine
Vigabatrin
ANTI-EPILEPTIC INTERACTIONS
CARBAMAZEPINE/PHENYTOIN/SODIUM VALPROATE? HIGH-RISK DRUGS, MUST KNOW IT ALL
Hepatoxicity: amiodarone, itraconazole, macrolides, alcohol
CYP inducer (CPPheno) inhibitor (Sodium Valproate)
Drugs that lower seizure threshold: Q-TTie! Quinolones (cipro, levo), Tramadol, Theophylline
valproate must NOT be prescribed in pt < 55 (male/ female) unless what
2 independant specialists ocnsider + document there is no other effective/ tolerated tx
and
PPP conditions are fulfilled
what to do if pregnancy suspected with pt on valproate?
DO NOT STOP. make urgent GP appt asap
ANTI-EPILEPTIC INTERACTIONS
CARBAMAZEPINE only?
Hyponatraemic drug (SSRI, diuretics)
ANTI-EPILEPTIC INTERACTIONS
PHENYTOIN only?
Anti-folates (Methotrexate, Trimethoprim)
phenytoin has anti folate effects thus can cause blood dyscrasias
ANTI-EPILEPTIC SIDE-EFFECTS
CARBAMAZEPINE/PHENYTOIN/SODIUM VALPROATE? DH^2BV
Depression+Suicide
Hepatotoxicity
Hypersensitivity
Blood Dyscrasia
Vitamin D Deficiency (bone pain)
(drugs that work on cyp almost always cause hepatotox)
trigger words in exam: bone pain –> vit D, joint pain.. rickets !
ANTI-EPILEPTIC SIDE-EFFECTS
CARBAMAZEPINE ONLY?
Hyponatraemia+Oedema
ANTI-EPILEPTIC SIDE-EFFECTS
PHENYTOIN ONLY?
Coarsening Appearance + Facial Hair
ANTI-EPILEPTIC SIDE-EFFECTS
SODIUM VALPROATE ONLY?
Pancreatitis
Teratogenic - must be on PPP
hypersensitivity eg skin rash, allergic rhinitis, asthma is a rare but potentially fatal SE of which anti-epileptics? CP3L
Carbamazepine
Phenytoin
Phenobarbital
Primidone
Lamotrigine
SKIN RASH?
Lamotrigine->Steven-Johnson syndrome
blood dyscrasia SE of which anti-epileptics C.VET.PLZ
Carbamazepine
Valproate
Ethosuximide
Topiramate
Phenytoin
Lamotrigine
Zonisamide
eye disorders can be a SE of which anti epileptics? and what disorder specifically
VT
Vigabatrin (reduced visual field)
Topiramate (secondary glaucoma)
which anti epileptic may cause encephalopathy
Vigabatrin
which 2 anti epileptics (GP) may cause resp depression
Gabapentin
Pregabalin
bc given for pain. think similar to opioids - also can cause resp depression
carbamazepine and phenytoin: high risk drugs !!
whats the therap range of carbamazepine
4-12mg/L (Carb, 4 letters, full 12 kind of)
signs of carbamaz toxicity HANDBAG
Hyponatraemia
Ataxia
Nystagmus
Drowsiness
Blurred Vision
Arrhythmias
GI Disturbances
PHENYTOIN
THERAPEUTIC RANGE?
10-20mg/L (same as theophylline)
PHENYTOIN
SIGNS OF TOXICITY? SsNA()tCH(e)D-V
snachd
Slurred Speech
Nystagmus
Ataxia
Confusion
Hyperglycaemia
Double Vision
EPILEPSY- DRIVING. safe to drive? need to inform dvla?
stop driving asap and inform dvla
if had first unprovoked (unknown cause)/ single isolated seizure, stop driving for X
6 months
if dont have another can start driving again
Established epilepsy: Y seizure-free, no impact on consciousness (+no history of unprovoked)
can drive
1 year
if have Medication change/withdrawal:
Should not drive for Z after last dose
6 months
Seizure occurs: License revoked for 1 year, but early relicense if treatment has been reinstated for 6 month+seizure-free
epilepsy in preg. continue therapy? yes no why
risk of harm to mother and fetus > risk of continued therapy
yes
what drug given to reduce risk of neural tube defects in first trimester for mother on anti epileptics
folci acid (5mg OD)
what injection admin at birth reduces risk of neonatal haemorrhage
vit K
which is the riskiest anti epilep drug in preg
Sodium Valproate (PPP)
which anti epileptic -> cleft palate
Topiramate
EPILEPSY- BREASTFEEDING, BABIES
MONOTHERAPY vs COMBINED?
Monotherapy- breast-feeding encouraged
Combined therapy/Risk factors- specialist advice
which anti epileptics ahve high presence in milk
PELZ
Primidone
Ethosuximide
Lamotrigine
Zonisamide
which antiepileptics associated with RISK OF DROWSINESS? BP2
Benzodiazepine
Phenobarbital
Primidone
which anti epileptics associated with WITHDRAWAL EFFECTS? BP2L
(if mother suddenly stops breastfeeding)
Benzodiazepine
Phenobarbital
Primidone
Lamotrigine
*BONUS:
Monitor infants for: sedation, feeding difficulties, weight gain and developmental milestones
