Anti-Epileptics Flashcards
Seizures are a ______ event due to an abnormal, hypersynchronous discharge from a mass of CNS neurons. It has diverse manifestations ranging from convulsion (observable) to an experience (subjective).
paroxysmal
A Single seizure due to \_\_\_\_\_\_\_\_\_\_ (i.e. provoked) is not necessarily epilepsy. They may include: \_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ Pyrexia Sleep deprivation
1 a correctable or avoidable circumstance
- Alcohol
- Hypoglycemia
These have a lower Risk of being Epilepsy: Single Seizure, Normal ____ and ______.
- EEG
2. Brain scan
These have a higher Risk of being Epilepsy: ______ Seizures, ____ EEG and abnormal brain scan.
- Previous (undiagnosed) seizures
2. Epileptiform
Seizures occur due to unbalanced ______ and ______ receptor / ion channel function which favour depolarization, leading to dysregulated discharge.
- excitatory
2. inhibitory
Causes of Epilepsy include: Congenital or hereditary Brain injury, scarring or \_\_\_\_\_\_ \_\_\_\_\_\_\_\_: meningitis or encephalitis Blood \_\_\_\_\_ alterations Metabolic disorders, eg., adrenal insufficiency leading to \_\_\_\_\_\_\_\_\_\_
- tumor
- glucose
- Infections
- hyponatremia
Generalized seizures generally involve whole brain and loss of consciousness. They include 4 different types. They are: 1. _____ (most dramatic type in movies), 2. ______ (zoning out), 3. Myoclonic and 4. Atonic.
- Tonic clonic
2. Absence
Partial seizures can be _____ (unimpaired consciousness) or _____ (impaired consciousness).
- simple
2. complex
_________ is a serious form of seizure (5 or more mins of seizure before recovery and enters another episode of seizure right away (medical emergency).
Status epilepticus
The rationale of antiepileptics is to ______ by altering Na+ and Ca2+ conductance during action potentials. This is done by enhancing effects of _________ neurotransmitters. We must note that not all compounds are effective against all types of seizures.
- decrease membrane excitability
2. inhibitory GABA (mainly GABA-A)
Phenytoin is suitable for all types of seizures except ______seizures. It exerts its effect via Blockade of ________ channels.
- absence
2. voltage-dependent Na+
Phenytoin has a relative narrow therapeutic range (plasma concentration 40-100μM) shows _____ kinetics and is contraindicated in _____ women.
- saturation
2. pregnant (teratogenic)
Carbamazepine is suitable for all types of seizures except ______seizures. It exerts its effect via Blockade of ________ channels.
- absence
2. voltage-dependent Na+
Carbamazepine is a CYP450 _____ , T½ shortens with repeated doses, accelerating elimination of other drugs. One potentially fatal side effect is ______
- inducer
2. Aplastic anemia
Valproate is suitable for all types of seizures except ______seizures. It exerts its effect via Blockade of ________ channels.
- (none), works for all seizures, including Absence
2. voltage-dependent Na+ and Ca2+
Valproate inhibits ______ , increasing GABA levels. It is Strongly bound to plasma proteins which allows it to ________________.
- GABA transaminase
2. displace other antiepileptics
Some dose related side effects of antiepileptics include: drowsiness, confusion, _______, _____, slurred speech, nausea, unusual behavior, mental changes, coma.
- nystagmus
2. ataxia
Some non- dose related side effects of antiepileptics include _____, acne, gingival hyperplasia, _____deficiency, osteomalacia, _______ reactions (including Stevens-Johnson syndrome)
- hirsutism
- folate
- hypersensitivity
BZDs can be used to treat epilepsy via _____ inhibitory GABA neurotransmitters.
potentiating effects of
Long acting BZDs have a duration of ____ but are not 1st line in treating epilepsy as they have ______.
- 1 - 3 days
2. high addictive potential
Intermediate acting BZDs have a duration of ____.
10-20hrs
Short acting BZDs have a duration of ____ but are usually not used for chronic antiepileptic use as multiple doses = more ______ and _______.
- 3 - 8hrs
- side effects
- addiction
Antiepileptic drug treatment strategy should be individualized according to the seizure ____, _______ syndrome, co-medication, comorbidity and the individual’s ______ (and/or those of their family and/or carers as appropriate).
- type
- epilepsy
- lifestyle and preferences
Patients should be commenced on _______ initially. Should the patient develop an adverse reaction or if the initial __________ is unsuccessful, _______________ should be tried.
- monotherapy
- monotherapy
- monotherapy using another drug
We want to start at _____ dose and ______ as epilepsy is a chronic lifelong condition. (prevent long term adverse effects from chronic dosing)
- lowest
2. monotherapy
All antiepileptic drugs licensed for monotherapy have _____ in newly diagnosed epilepsy. For this reason, the medicine the prescribing physicians are most familiar with can be used.
similar efficacy
Carbamazepine, phenytoin and sodium valproate can be considered first line treatments for newly diagnosed _______ and ___________ seizures.
- partial
2. generalized tonic clonic
Routine checking of antiepileptic drug levels without _______ is not required, and is ______.
- a clear clinical indication
2. not cost effective
Antiepileptic drug levels may help clinical management under the following clinical indications:
(1) Assessment of ________ to drug treatment for patients with refractory epilepsy
(2) Assessment of ______ due to possible antiepileptic drug toxicity
(3) _______ of phenytoin dose.
- compliance
- symptoms
- Titration
The following present increased risk for breakthrough seizures:
– ________ to antiepileptic medication or drug
– Interactions with antiepileptic medications lowering blood levels of antiepileptic drugs. (i.e. ______)
– _____ abuse
– _____ deprivation
– Concurrent illness
- Non-compliance
- Valproate
- Alcohol
- Sleep
Plan for a 35 year old female presenting with a Single seizure, CT normal and EEG normal?
Observe as 60-70% chance of unnecessary treatment/side effects, 30-40% chance of recurrence.
Treatment unlikely to alter long term prognosis.
Plan for a 29 year old newly married female. Newly diagnosed epilepsy. Which 1st line antiepileptic should we give and what are things to consider?
– Phenytoin
– Carbamazepine
– Valproate
Phenytoin is teratogenic.
Consider Efficacy, safety, cost effectiveness (1st line meds are cheaper).
Use lowest dose of C or V (both 1st line) which control seizures.
When it comes to epilepsy, we must “Treat the _____, NOT the ______”.
- patient
2. numbers
