Anti-epileptics Flashcards
What are the two mechanisms for anti-epileptic medication?
1- By suppressing focus and prevent spread by blocking Na+ into cell of Ca2+
2- by increasing activity of GABA (which is inhibitory), enhancing GABA channels, more Cl- into cell
How do Na+ channel blockers suppress seizures?
By binding and stabilising inactive form of Na+ channel, hyperpolarises cell, increases threshold and prolongs refractory period
Name 4 Na+ channel blockers used for epilepsy
Phenytoin, carbamazepine, lamotrigine, sodium valproate
What are the SE of phenytoin?
P450 induction, diplopia, nystagmus, ataxia, sedation, gum hyperplasia
Uses and SE of Carbamazepine
Used for tonic-clonic and partial seizures
Little sedation :)
P450 induction, rash, nausea, jaundice and ADH activity
Uses of Lamotrigine
Used for tonic-clonic, long half life, rare SE of angioedema and toxic epidermal necrolysis
What is the first line drug for petit mal?
Sodium valproate
Enhances synthesis and inhibits breakdown of GABA as well as Na+ blocker
Name 3 GABAa channel enhancers
Phenobarbitone, gabapentin, pregabalin
When do you not use phenobarbitone?
Not used in petit-mal
What is lamotrigine?
Na+ channel blocker used in epilepsy
What is phenytoin?
Na+ channel blocker used in epilepsy
Name 2 benzodiazepines used in epilepsy treatment and when they are used
Diazepam- status epilepticus
clonezepam- tonic clonic seizures
How does vigabatrin work?
Inhibits breakdown of GABA
How does retigabine work?
Neuronal K+ channel opener, hyperpolarises neuron
How does tiagabine work?
Sustains GABA in synapse
