ANTIEPLIPETICS

Question 1

What are the positive allosteric modulators of GABA?

Answer 1

-benzodiazepines - clonazepam, barbiturates - phenobarbital

Question 2

Why are barbiturates avoided?

Answer 2

can cause respiratory depression

Question 3

What is the drug that inhibits the enzyme responsible for the inactivation of GABA?
MOA

Answer 3

Vigabatrin - irreversibly inhibits GABA-T
= increased levels of GABA as it is not broken down

used to treat resistant epilepsy in combination with other drugs
- irreversible therefore high risk

Question 4

What drug inhibits the reuptake of GABA into the presynaptic neuron and glial cells?

Answer 4

Tiagabine - inhibits GAT-1 used in combination to treat focal seizures

Question 5

What is the drug that inhibits calcium channels?

Answer 5

• gabapentin - gaba analogue but doesn’t act as a GABA mimic
• inhibit opening of P/Q type calcium channels on neocortex and hippocampus found in excitatory neurones

Question 6

What is the drug responsible for inhibiting sodium channels?

Answer 6

Phenytoin
- inhibit opening of sodium channels found on excitatory neurones
- use-dependent block - reducing aelectrical activity associated with epileptic seizures
- inhibits repetitive neuronal firing by stabilising channels in an inactive state

Question 7

What is the drug responsible for opening of potassium channel

Answer 7

retigabine

• causes hyper polarisation by activating voltage gated KCNQ2 + KCNQ3
• resulting in efflux of K = hyper polarisation
• used as combination therapy for focal seizures

Question 8

What is the drug that is a synaptic vesicle protein 2a inhibitor?

Answer 8

Levitiracetam
- binds to SV2A which allows glutamate to be packaged into release vesicle therefore stops the release of glutamate release from synaptic cleft

• slective inhibition of firing patterns associated with seizures in the hippocampus

Question 9

What drug is an AMPA antagonist?

Answer 9

perempanel - noncompetitive antagonist
- blocking AMPA receptors reducing effect of glutamate

used for treatment of partial onset seizures in patients over 12ys

Question 10

What are the anti epileptic drugs that have more than one MOA?

Answer 10

Valrpoate

Question 11

What is the MOA of valproate

Answer 11

• enhanced GAD activity
• inhibition of histone deactylase
• inhibiting enzyme which influences which parts of the genome that are expressed
• effects on ions channels - affecting firing activity

used in all generalised seizures
- used in pain

Question 12

What anti-epileptic drugs are used for anxiety as well

Answer 12

gabapentin
benzodiazepines