module three: treatment of epilepsy
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Module Three: Treatment of Epilepsy. Module Three: Objectives. Upon completion of Module Three the participant will: Describe the main treatment options for epilepsy Identify factors essential in the selection of appropriate medications for epilepsy - PowerPoint PPT PresentationTRANSCRIPT
+Module Three: Treatment of Epilepsy
+Module Three: Objectives
Upon completion of Module Three the participant will:Describe the main treatment options for epilepsyIdentify factors essential in the selection of appropriate medications for epilepsyReview the indications for epilepsy surgery Discuss the benefits of dietary therapy for epilepsy
+Treatment of Epilepsy
Individuals with epilepsy have a variety of treatment options Medications are the first option and the mainstay
of treatment for most people
AEDs treat the symptoms, not the underlying disease
Surgical procedures and implantable devices are also options that are considered if seizures persist
Dietary therapies provide another treatment option in some patients when medicines don’t work
+Decision to Treat with Medications Most patients with first time seizures are not placed on medications
Medications to treat seizures are usually called antiepileptic drugs or AEDs
Patients are treated if: two or more seizures abnormal imaging abnormal neurological exam abnormal EEG family history of seizures
Treatment begins with one drug
+Antiepileptic Drugs (AEDs)
Goals of medication therapy:No seizures
No side effects – tailor side effect profile to patient-specific factors
Improvement in quality of life
More accurately called ‘Anti-Seizure Drugs’
+Antiepileptic Medications (AED)
Good oral absorption and bioavailability
Most metabolized in liver but some excreted unchanged in kidneys
1st generation AEDs generally have more severe CNS sedation than newer drugs
Drugs chosen based on mechanism of action, side effect profile, and impact on comorbid conditions, ie. migraine, depression
Add-on therapy is used when a single drug does not completely control seizures
+Ideal Characteristics for AEDs
Few adverse effects
High CNS penetrance
Rapid onset of action
No or few drug-drug interactions
Long half-life for daily or twice a day dosing
Intravenous route available
Oral liquid preparations important for children and people with impaired swallowing
Available in different dosage strengths
Affordable, covered by health insurance
+Things to keep in mind…
Treatment with medication is successful for a large percentage of individuals, but at least 30 to 40% don’t respond to current AEDs
Multiple dosing times for medications may lessen adherence
Certain types of medications work best for certain forms of epilepsy
+Medication Adherence
The extent to which a person takes medication as prescribed Also referred to as compliance Using a self-management model, adherence
is one aspect of medication-taking behaviors
Missed AEDs are one of the most common reasons for breakthrough seizures
Complex medication regimes, poor memory, and cost are barriers to adherence
+Pharmacokinetics
Absorption: How long it takes for medicine to be absorbed into the bloodstream Determined by route of intake, may be affected
by food Absorption rate can vary for different medicines Meds that may affect rate of absorption should
not be given at same time as AEDs, i.e. antacids
Distribution: How the drug is distributed through the body AEDs with a high degree of protein binding tend
to have more drug interactions
+Pharmacokinetics
Metabolism and Elimination: Drugs may be broken down in the liver and excreted through the kidneys AEDs metabolized by the liver tend to have
more drug interactions
Bioavailability: How much drug gets into the brain to work as intended. The net result of the absorption, distribution,
metabolism, and elimination process
+Drug Concentration: Establishing AED Doses
Some drugs require a large initial dose to achieve a desired concentration in the body, called a ‘loading dose’
Some AEDs are tolerated better when started at slowly at low doses
The dose necessary to MAINTAIN a desired concentration over time is called the ‘maintenance dose’ and may vary according to patient and drug specific factors
+Laboratory Monitoring
Serum drug levels serve as a guideline in determining therapeutic dosing
Serum levels of newer drugs may not be as important since the therapeutic window for dosing is much larger
Additional monitoring (i.e. liver function tests, CBC, or renal function) may be needed, depending on specific drug
+Considerations for AED Choice
Ability to give alone (monotherapy) or together with other AEDs (polytherapy)
Side-effect profile
Need for laboratory monitoring
Drug-drug and drug-food interactions
Cost and availability
Patient’s ability to manage the medication(s)
+General Instructions
Patients must take medications as prescribed on a daily basis to maintain a therapeutic blood level to prevent seizures
Patients should not abruptly stop medications – raises risk for seizure emergencies
Factors that can influence how the drug gets into the body, works in the body, and is metabolized and eliminated can interfere with the serum blood drug levels and interact with other medications
+1st and 2nd Generation AED’s
The oldest drugs used in the treatment of epilepsy include phenobarbital, introduced in 1912, and phenytoin (Dilantin), in use since 1938-these drugs are considered as 1st generation
2nd generation AED’s have been in place since the early 1990’s
+1st Generation AEDs
1857- Bromides
1912-Phenobarbital
1938-Phenytoin (Dilantin)
1954- Primidone
1960- Ethosuximide (Zarontin)
1974-Carbamazepine (Tegretol)
1975 Clonazepam (Klonopin)
1978- Valproate (Depakote)
+ 2nd Generation AEDs
1993- Felbamate (Felbatol)
1993- Gabapentin (Neurontin)
1995-Lamotrigine (Lamictal)
1997-Topiramate (Topamax) Tiagabine (Gabitril)
1999- Levetiracetam (Keppra)
2000- Oxcarbazepine (Trileptal
2000- Zonisamide (Zonegran)
2005- Pregabalin (Lyrica)
2009- Lacosamide (Vimpat)
2009- Rufinamide (Banzel)
2010-ACTH (Acthar)
2011- Clobazam (Onfi)
2012 – Ezogabine (Potiga)
+Generic Drugs
Generic versions are available for many epilepsy medications
While FDA states that generic medications are comparable to brand name AEDs, people have reported differences in seizure control and/or side effects during switches between generic to brand, or between different generic formulations
Patients should discuss the use of generics with their provider
For more information: AES consensus statement on generic drug substitution http://www.aesnet.org/go/press-room/consensus-statements/drug-substitution
+Medication Side Effects
Awareness of common side effects is important
Side effects can be unpredictable What works well for one person, may not
work well for the next
Side effects can be dose dependent Often depends on person's chemistry and
metabolism, height, weight, etc. Most common dose dependent side effects
affect the CNS
+Types of Side Effects
• Dose-related: the higher the dose, the more likely the effect• Common: drowsiness, irritability, nausea,
clumsiness, imbalance, blurry or double vision
• Idiosyncratic: Occurs irrespective of dose• Changes in appetite or weight change,
osteopenia or osteoporosis, cosmetic effects, tremors, fatigue, cognitive effects, mood changes
• Allergic: i.e. rash, anaphylaxis
+
Serious Side Effects Prolonged fever
Rash
Nausea/vomiting
Severe sore throat
Mouth ulcers
Easy bruising
Pinpoint bleeding
Weakness
Fatigue
Swollen glands
Lack of appetite
Abdominal pain
+Drug Interactions
How well an AED works may be affected by other medications a person is taking
Interactions may occur between AEDs or between AEDs and other prescription or over-the-counter medications, for example, warfarin, antibiotics, and other commonly used medications
+Rescue Treatments
Rectal diazepam gel (Diastat™) approved by FDA for out of hospital use by non-medical people
PRN benzodiazepines are first line treatment and can be given in the home, community, ambulance or hospital.
Autoinjectors and intranasal forms are being tested. Vagus nerve stimulator magnets - non-drug
intervention for seizure first aid Rescue Treatments do not replace routine seizure
first aid
Used to stop prolonged or clusters of seizures
+Rescue Treatments
Rescue AEDs can be given by mouth, bucally, rectally or intravenously, depending on the setting and who is giving the AED.
Patients should have specific instructions on when to use rescue AEDs or VNS magnet
Include when to seek medical care and emergency services in seizure plans and protocols.
Resources from Epilepsy Foundation: Seizure Action Plans for School Settings My Seizure Response Plans My Epilepsy Diary
General Instructions
+When Seizures Do Not Respond to AEDs
Patients whose seizures are not controlled after 2 or more trials of appropriate medications should be referred to the next level of care for appropriate evaluation and treatment. For example,
Refer to a neurologist if seizures persist after 3 months of care by a primary care provider
Refer to an epilepsy specialist if seizures persist despite treatment with general neurologist for 12 months
+Epilepsy Surgery
Failure of AEDs to control seizures – refractory epilepsy
Ability to identify focus of seizure generation in the brain
Able to remove focus or operate safely
Seizures are ‘disabling’ – consider impact of seizures on quality of life
Benefits versus risks of surgery and of refractory epilepsy
Indications
+Epilepsy Surgery
Determine that seizures are refractory to AEDs
Video EEG telemetry to localize seizures
Scans to identify possible causes and location of seizure focus (CT, MRI, PET, SPECT, MEG)
Multidisciplinary evaluations – medicine, nursing, psychiatry, social work, psychology
Neuropsychological testing to evaluate cognitive function, assist in localizing seizure focus
Wada test – to identify location of language and memory functions
Presurgical Evaluation
+Epilepsy Surgery
Most common type of epilepsy surgery is resection in temporal or frontal lobe
Outcomes of surgery depend on the type and location of surgery, whether all or most of the epileptogenic area was removed and other patient-specific factors
+Vagus Nerve Stimulation (VNS) Therapy
30
Used as adjunctive therapy A programmable pulse
generator implanted subcutaneously in upper left chest
Electrode wrapped around the left vagus nerve
Exact mechanism of action not known
Stimulation-related side effects may include hoarseness, coughing and shortness of breath
+VNS Therapy- Use of Magnet
Stop side effects: Magnet temporarily
stops stimulation
Hold magnet over generator in chest for at least 6 seconds.
Stimulation will not be delivered as long as the magnet is over the generator.
To restart stimulation, remove the magnet.
Seizure first aid:
Magnet may activate additional burst of stimulation
Swipe magnet over generator in chest for one second (“one one-thousand one”)
Wait 60 seconds, then repeat, or as recommended in seizure action plan
+ Dietary Therapies for Epilepsy
Ketogenic Diet (KD)
Modified Atkins Diet (MAD)
Low Glycemic Index Treatment (LGIT)
+Dietary Therapies
For people with refractory epilepsy, when medications don’t work or are not tolerable
May allow reduction in AEDs if seizures can be controlled.
Ketogenic diet is the most restrictive, may require a hospitalization and few days of fasting to start it. Difficult for older children and adults to tolerate
Modified Atkins and Low Glycemic diets are less restrictive and easier to tolerate by many people
Indications and General Tips