Anticonvulsants

Question 1

what is epilepsy?

Answer 1

 is the condition of recurrent, spontaneous seizures arising from abnormal, synchronous and sustained electrical activity in the brain. Too much excitation. Uncontrolled activity
 A SEIZURE is an episode of neurological dysfunction of abnormal firing of neurones manifesting as changes in motor control / sensory perception / behaviour / autonomic function.

Question 2

what is the pharmcological treatment of epilepsy?

Answer 2

 The various classes of antiepileptic drugs (AEDs) act to restore the inhibitory function in the brain and therefore suppress seizure activity.
 Treatment depends in part on the type of seizure(s) experienced by the patient, this will then determine an appropriate antiepileptic (also known as anticonvulsant) drug regimen, or further treatment could involve surgery to remove the focus of the seizure.

Question 3

what would you use for an generalised tonic/clonic?

Answer 3

1st line

Carbamazepine, Lamotrigine, Sodium Valproate, Oxcarbazepine

Question 4

what would you use for a tonic or atonic seizure?

Answer 4

Sodium Valproate

Question 5

what would you give for an absence seizure?

Answer 5

Ethosuximide, Lamotrigine, Sodium Valproate

Question 6

what would you give for a myoclonic seizure?

Answer 6

Levetiracetam, Sodium Valproate, Topiramate

Question 7

what would you give for a focal seizure?

Answer 7

Carbamazepine, Lamotrigine, Levetiracetam, Oxcarbazepine, Na Valproate

Question 8

what does GABA do/

Answer 8

calms the brain
GABA enchanching drugs would be used as 
- anxiolytics
- sedatives
- anti-convulsants

Question 9

what does glutamate do?

Answer 9

excites the brain
- this might cause convulsion
but
glutamtate blocking drugs could be used asanti-convulsants

Question 10

why are GABA and glutamate important for neurotransmission?

Answer 10

 Regulate and control many functions in the brain- side effects
 Potential for role in very wide range of neuroscience disease states
 Challenge is achieving benefit without side-effects
 We now know understand the requirements for safe and effective receptor modulation (positive/negative)

Question 11

what is neuronal firing?

Answer 11

– Dynamic target of seizure control in management of epilepsy is achieving balance between factors that influence excitatory postsynaptic potential (EPSP) and those that influence inhibitory postsynaptic potential (IPSP).

Question 12

what the four main categories of anticonvulsants?

Answer 12

1) drugs that inhibit Na+ channels
(2) drugs that inhibit calcium channels
(3) drugs that enhance GABA-mediated inhibition- several ways to do this
(4) drugs that inhibit glutamate receptors- however glutamate is everywhere in the brain, this could give problems- side effects.

Question 13

how does a drug inhibit the sodium channels?

Answer 13

drug would prevent the opening of sodium channels so that sodium could no longer rush in

Question 14

what happens if calcium channels are inhibited?

Answer 14

influx of calcium is needed to transmit so if you block this you are toning down excitation

Question 15

how do drugs enhance GABA- mediared inhibition?

Answer 15

In response to an action potential and the presynaptic elevation of intracellular Ca2+, GABA is released into the synaptic cleft by fusion of GABA-containing vesicles with the presynaptic membrane

Question 16

what does activation of AMPA cause?

Answer 16

Activation of AMPA receptors causes depolarisation (Na moves in and pushes towards threshold) which removes the Mg2+ block, and thereby activates

Question 17

what is anxiety?

Answer 17

 Anxiety is a NORMAL component of everyday life. It is a normal response to a stressful or threatening situation. It becomes a disorder when it is inappropriate or disrupts an individual’s social life- when it becomes debilitating
 Anxiety disorders are a group of mental disorders characterized by excessive feelings of anxiety and fear- can’t control or get past them

Question 18

what is the mechanism ofaction of benzodiazepine/

Answer 18

 Typically made up of two α and two β subunits among the five subunits, though the particular subunit composition often varies widely among brain regions and species
 Drugs bind at the subunits but different site to where the GABA binds- can keep the channels open longer- more Cl in and more inhibition
 The receptor complex possesses sites of action for a number of clinically important drugs (Benzodiazepines)
 These are known as GABA modulators because they increase or decrease the effect of GABA (Note: some have no effect in the absence of GABA