Dr.Ott Seizure disorder Flashcards
Risk factors for seizure recurrence
<2 years seizure free
onset of seizure after age 12
2-6 years before good seizure control in treatment
withdrawal of phenytoin or valproate
What is status epilepticus and what can we use to treat it
A continuous seizure lasting 5 minutes or more, or two seizures back to back with incomplete recovery between them
Treatment
- benzodiazepines: lorazepam, midazolam
Treatment of status epilepticus treatment
0-5 minutes
- start ECG and oxygen
5-20 minutes
- IV lorazepam or IV midazolam
20-40 minutes
- if not controlled IV fosphenytoin, IV valproic acid
Oral phenytoin dosing considerations
must obtain both phenytoin serum concentration and serum albumin in the same blood draw
therapeutic serum concentration range - 10-20
Valproate dosing
IV to PO conversion 1;1mg/mg
desired serum concentration = 80mcg/mL
First line treatment for Partial onset (focal onset)
Carbamazepine
Lamotrigine
Levetiracetam
Oxcarbazepine
Phenytoin
Pregabalin
Valproate
First line treatment for Tonic- Clonic (generalized)
Carbamazepine
Lamotrigine
Oxcarbazepine
Phenobarbital
Phenytoin
Valproate
First line treatment for Absence Generalized
Ethosuximide
Lamotrigine
Valproate
First line treatment for Myoclonic (Focal or generalized)
Levetiracetam
Topiramate
Valproate
First line treatment for Lennox-Gastaut Syndrome
Felbamate
Lamotrigine
Rufinamide
Topiramate
Valproate
First line treatment for Atonic (generalized)
Valproate
Lamotrigine
Rufinamide
Topiramate
Cyp1A2 inducers
Carbamazepine
phenobarbital
phenytoin
Cyp2C9 inducers
Carbamazepine
phenobarbital
phenytoin
Cyp3A4 inducers
Carbamazepine
phenytoin
Lamotrigine
oxcarbazepine
topiremate
phenobarbital
UGT inhibitors
Valproate
DRESS syndrome
life threatening
generally occurs 2-6 weeks after initiation of drug therapy
increase risk in patients who are positive for the HLA-A*3101
which drugs are associated with causing DRESS syndrome
Carbamazepine, Cenobamate, lamotrigine, phenobarbital, phenytoin, valproate, zonisamide
Anti-seizure drug therapy in pregnancy
Drug serum concentration may change during pregnancy due to volume of distribution
Valproate not used in pregnancy because may lower IQ of fetus
Supplemental folic acid (5mg daily) should be considered during pregnancy
Infants should receive vitamin K 1mg IM at birth to decrease risk of hemorrhagic disease
Antiseizure drug withdrawal syndrome
abrupt discontinuation
may cause recurrence of seizures, doses of antiseizure medication should always be tapered for discontinuation
Contraceptive drug interaction
This interaction can be minimized by using higher dose estrogen contraceptives- warning for increased thromboemoblism
can use progestin only contraceptives- depot forumulation
estrogen can significantly decreased lamotrigine serum concentration (50%) and lamotrigine decreased estrogen concentration
Psychiatric side effects of anti-seizure medications
Levetiracetam - psychosis, suicidal thoughts, unusual mood changes, worsening depression
Perampanel - boxed warning - dose related serious and life theratening neuropsychiatric events
Valproate - acute mental status changes related to hyperammonemia
Topiramate - associated with cognitive dysfunction if the dose is increased too rapidly, use a slow dose titration
Visual abnormalities
Topiramate - post marketing warning for vision loss, myopia, retinal detachment
vigabatrin is contraindicated in patients who have other risk factors for irreversible vision loss.
Carbamazepine interactions
Carbamazepine: strong P450 (1A2, 2C9, 2C19, 3A4) and p-glycoprotein inducer (induces own metabolism)
Oxcarbazepine induces 3A4
Valproate clinical pearl
valproate can cause thrombocytopenia - monitor CBC/Platelets can cause PCOS, Weight gain, sedation
