EPILEPSY DRUGS Flashcards
What is epilepsy?
A chronic disorder characterized by recurrent seizures due to abnormal synchronized brain activity.
What percentage of patients achieve seizure control with antiepileptic drugs (AEDs)?
60-70% achieve adequate control with appropriately chosen AEDs.
When are antiepileptic drugs indicated?
When two or more seizures occur within a short interval (6 months - 1 year).
What are common seizure triggers?
Fatigue stress
What are the two major types of seizures based on etiology?
Primary (idiopathic) and secondary (symptomatic due to an identifiable cause).
What is the mechanism of seizure generation?
An imbalance between excitation (glutamate Na+
What is the main excitatory neurotransmitter in the brain? .
Glutamate
What is the main inhibitory neurotransmitter in the CNS? .
GABA
What are narrow-spectrum antiepileptics?
Drugs effective mainly for focal and secondary generalized seizures (e.g. phenytoin
What are broad-spectrum antiepileptics?
Drugs effective for both focal and generalized seizures (e.g. valproate
What is the mechanism of action of phenytoin?
Blockade of Na+ and Ca2+ channels reducing excitatory transmission and potentiating GABA.
How is fosphenytoin different from phenytoin?
Fosphenytoin is a water-soluble prodrug suitable for IV or IM use in status epilepticus.
What are indications for phenytoin?
Partial and generalized tonic-clonic seizures and status epilepticus (slow IV infusion).
What are common adverse effects of phenytoin?
Gingival hyperplasia hirsutism
What is carbamazepine primarily used for?
Partial seizures and tonic-clonic seizures; also used for bipolar disorder and trigeminal neuralgia.
What are the main adverse effects of carbamazepine?
GI upset
hyponatremia
What is sodium valproate effective for?
A broad-spectrum AED for all types of epilepsy including generalized tonic-clonic
What are major side effects of sodium valproate?
GI upset weight gain
What is the primary indication for ethosuximide?
Absence seizures especially in children.
What is the mechanism of action of ethosuximide?
Selective inhibition of T-type Ca2+ channels in thalamic neurons.
What are common side effects of ethosuximide?
GI distress fatigue
What is phenobarbital’s mechanism of action?
Potentiates GABA-A receptor activity prolonging Cl- channel opening and reducing excitability.
What is phenobarbital used for?
Generalized tonic-clonic seizures partial seizures
What are adverse effects of phenobarbital?
CNS depression cognitive impairment
What is topiramate used for?
Partial generalized tonic-clonic
What are major side effects of topiramate?
Cognitive dysfunction weight loss
What is the primary mechanism of lamotrigine?
Blocks Na+ channels and inhibits release of excitatory amino acids (glutamate aspartate).
What is lamotrigine commonly used to treat?
Partial and generalized tonic-clonic seizures Lennox-Gastaut syndrome
What serious side effect is associated with lamotrigine?
Steven Johnson syndrome (severe skin reaction).
What is levetiracetam’s unique mechanism?
Binds to SV2A protein to modulate neurotransmitter release and stabilize neuronal activity.
What are indications for levetiracetam?
Partial-onset generalized tonic-clonic
What is the treatment approach for status epilepticus?
Initial benzodiazepine (lorazepam or diazepam) followed by phenytoin or phenobarbital if needed.
What is the preferred approach to AED therapy?
Monotherapy as it reduces adverse effects and drug interactions.
When can AED therapy be discontinued?
After 2+ years of seizure freedom with a favorable prognosis (single drug
What precautions are needed when AEDs are used during pregnancy?
Use the lowest effective dose supplement with folate
What AEDs are typically considered safe for breastfeeding?
Carbamazepine
phenytoin
