Chapter 71 - Seizure & Epilepsy Flashcards
Seizure types
- Tonic - clonic: uncontrolled jerking movement
- Absent: momentary loss of awareness
Diagnostic tools
- An electroencephalogram (EEG), the most common test used to diagnose epilepsy, records electrical activity in the brain.
- An EEG can show abnormal patterns even when the patient is not having a seizure.
- Brain imaging with a CT or MRI can identify some conditions that can provoke seizures, including brain tumors or damage from a stroke.
DRUGS THAT CAN LOWER THE SEIZURE THRESHOLD
- Bupropion
- Clozapine
- Theophylline
- Varenicline
- Carbapenems (esp. imipenem)*
- Lithium*
- Meperidine*
- Penicillin*
- Quinolones*
- Tramadol*
- Acyclovir
- Cephalosporins
- lindane
- Mefloquine
- Metoclopramide
- Valacyclovir
Classification of seizure
classified into three main types based on where the seizure starts in the brain:
1) Focal seizures
- Start on one side of the brain but can spread to the other side.
- Focal seizures are further classified based on the patient’s awareness during the seizure.
- If a focal seizure results in no loss of consciousness, it is called a focal aware seizure, previously known as a simple partial seizure.
- If the patient experiences loss of consciousness, it is called a focal seizure with impaired awareness, previously known as a complex partial seizure.
2) Generalized seizures
- Start on both sides of the brain
- Patients with generalized seizures experience loss of consciousness or are unaware during the seizure event.
- Absent seizure is a type of generalized
3) Unknown onset seizures
- if the location of the beginning of the seizure is not known (e.g., the seizures are unwitnessed or occur during the night).
All seizure types can be described based on the patient’s symptoms.
motor and non motor sx
Motor symptoms include:
- Sustained rhythmical jerking movements (clonic)
- Limp or weak muscles (atonic)
- Muscle twitching (myoclonus)
- Rigid or tense muscles (tonic)
Non-motor symptoms include:
- Changes in sensation, emotions, thinking or cognition.
- Generalized seizures with non-motor symptoms are called absence seizures, which typically present as staring spells.
seizure management
- less than 2 min –> no ttmt needed
- Status epilepticus (SE) is a seizure that lasts beyond five minutes because the normal mechanisms that terminate seizures are not working.
- At 30 minutes, long-term damage can occur.
This is a medical emergency, and emergency treatment should begin with any seizure that lasts longer than five minutes.
Acute Seizure management
- Initial treatment is a benzodiazepine injection.
- Intravenous (IV) access can be difficult during a seizure; if it is not possible to connect an IV line, midazolam can be given intramuscularly (IM)
- If the patient is not receiving urgent medical care (i.e., not in a medical facility), diazepam rectal gel (DiastatAcuDial), or intranasal or buccal midazolam are non-injectable options.
- The DiastatAcuDialis given to patients (or caregivers, such as parents) who are at risk of long-lasting seizures; dispensing and counseling requirements are essential
acute seizure management
1) 0-5 minutes: Stabilization phase
- Time the seizure
- Start ECG,oxygen may be needed
- Check AED levels, electrolytes, if BG low - treat with D25-D50
2) 5-20 minutes: Initial treatment phase
If seizure continues:
- Give IV lorazepam (Ativon) or
- IM midazolam (Versed)
Alternatives if the above are not available:
- Rectal diazepam (Diastot),
- Intranasal or buccal midazolam
3) 20·40 minutes Second treatment phase
If seizure continues:
- Give regular AED: IV fosphenytoin, valproic acid, levetiracetam (phenobarbital if others are unavailable)
- If seizure lasts longer, there is no clear treatment
Diastat Acudial Dispensing
- Syringes MUST be dialed to the right dose and locked BEFORE DISPENSING.
- Syringes come in 2.5, 10 and 20 mg.
Chronic seizure management
- 1st line: AED
- AEDs should not be stopped abruptly as this can lead to seizures.
Non-drug and alternative options for chronic seizure treatment include:
- Medical marijuana {cannabis),
- A ketogenic diet,
- Vagal nerve stimulation
- Surgical intervention.
The Embrace2 smartwatch is an FDA-cleared medical device that monitors seizures in adults and children 6 years of age and older.
Medical Marijuana (Cannabis)
- Cannabidiol, or CBD (Epidiolex), was the first cannabis- derived medication approved by the FDA to treat rare forms of epilepsy.
- Epidiolex does not contain tetrahydrocannabinol (THC), but there are other CBD and medical marijuana products available that contain varying amounts of THC. - Pharmacists should consider the impact of additive CNS side effects, particularly with THC-containing products (e.g., somnolence, euphoria, possible anxiety and paranoia), and the potential for drug interactions from the THC and CBD components.
Ketogenic Diet
- Pt with refractory seizures (not responding to medications).
- The diet contains high fats, normal protein and low carbohydrates (usually a 4:1 ratio of fats to combined protein and carbohydrates).
- This forces the body to break down fatty acids into ketone bodies as an energy source.
- Ketone bodies pass into the brain and replace glucose. - This elevated ketone state is called ketosis, and can lead to a reduction in seizure frequency.
Ethosuximide indication
Absence seizures
- T-Type Ca channel blocker
(i’m absent, eh though it sucks)
Main drugs to treat focal and generalized seizures
- Lamotrigine (Na)
- Levetiracetam (Ca + inc GABA)
- Topiramate (Na)
- Valproic acid (GABA)
Val leve toi cz lammo l tapi
Narrow spectrum AED
1- Carbamazepine (Na)
2- Oxcarbazepine (Na + Ca)
3- Lacosamide (Na)
4- Phenobarbital (Potentiate GABA)
5- Phenytoin (Na)
6- Fosphenytoin (Na)
Car bas ma zepine / ox car bas zepine
Lacoste
fen toi? fos fen toi?
fen barb (bread)
Pregabalin and gabapentin (Ca) are used commonly for:
not for epilepsy;
they are used to treat neuropathic pain.
AEDs dec abnormal electrical activity by either:
■ Inc GABA
■ Dec Glutamate
■ Blocking (or altering) Ca channels, which slows down or stops transmission of the electrical signal
■ Blocking Na channels, which decreases the neurons firing rate
Inc GABA
- Benzodiazepine
- Valproic Acid
- Phenobarbital (enhance/ potentiate GABA)
- Levetiracetam
Blocking (or altering) Ca channels, which slows down or stops transmission of the electrical signal
- Levetiracetam (Ca + GABA)
- Ethosuximide (T type Ca chanel blocker)
- Pregabalin/ Gabapentin (used for neuropathic pain)
- Oxcarbazepine (Ca + Na)
Blocking Na channels, which decreases the neurons firing rate
- Oxcarbazepine (Ca + Na)
- Carbamazepine
- Lamotrigine
- Phenytoin/ Fosphenytoin
- Topiramate
- Lacosamide (?)
SE of Carbamazepine. Oxcarbazepine and Eslicarbazepine
- Hyponatremia,
- rash,
- enzyme induction
SE of Gabapentin and Pregabalin
- Weight gain, peripheral edema, mild euphoria
- Used primarily for neuropathic pain
SE of Phenobarbital and Primidone (prodrug of phenobarbital)
- Sedation, dependence/tolerance/overdose risk, enzyme induction
SE of Topiramate and Zonisamide
- Weight loss, metabolic acidosis
- Nephrolithiasis and oligohidrosis/hyperthermia (in children)
what to supplement with?
Supplement with:
- ALL AEDs: calcium and vitamin D
- Women of childbearing age: folate
- Valproic acid: carnitine
- Lamotrigene & valproic acid: if alopecia develops supplement with selenium and zinc
Lamotrigine Brand
- Lamictal,
- Lamictal ODT,
- Lamictal Starter Kit,
- Lamictal XR,
- Subvenite,
- Subvenite Starter Kit-Blue, Green, Orange
Lamotrigene dosing
Initial:
- Weeks 1 and 2: 25 mg daily
- Weeks 3 and 4: 50 mg daily
- Week 5 and on: can inc by 50 mg daily every 1-2 weeks
MaintenanceDose:
300 - 400 mg daily, divide BID, unless using XR (daily)
Lamotrigene boxed warning
- Serious skin reactions, including SJS/TEN (rate of rash is greater in pediatrics than adults);
- inc risk with higher than recommended starting doses, dose escalation or when used with valproic acid
Warning & se of lamotrigene
WARNING
- Risk of aseptic meningitis,
- blood dyscrasias,
- cardiac rhythm abnormalities,
- multiorgan hypersensitivity (DRESS) reactions,
- serious rare immune system reaction [hemophagocytic lymphohistiocytosis (HLH)] that can be fatal
SIDE EFFECTS
- Alopecia (supplement selenium and zinc),
- N/V,
- somnolence,
- rash,
- tremor,
- ataxia,
- impaired coordination,
- dizziness,
- diplopia,
- blurred vision
Lamotrigene drug interactions
- Valproic acid inc lamotrigine concentrations more than two- fold. Use lower dose starter kit (blue box).
- Carbamazepine, phenytoin, phenobarbital, primidone, lopinavir/ritonavir, atazanavir/ritonavir and rifampin J,lamotrigine levels by 40%. Use the higher dose starter kit (green box).
- Oral estrogen-containing contraceptives J, lamotrigine; higher maintenance doses of lamotrigine may be needed.
