the use of meds for epilepsy

Question 1

antiepileptic drugs

Answer 1

• diazepam (first line - always used first)
• phenobarbital
• pentobarbital
• potassium bromide
• levetiracetam
• midazolam
• propofol

Question 2

MOA and how they work

Answer 2

• inhibition of sodium or calcium channels
• activate chloride channels instead
• activation of GABA and glycine receptors
• inhibition of excitatory neurotransmission (Ach, serotonin and glutamate)

Question 3

sodium channel blocking meds

Answer 3

• carbamazepine & phenytoin

- little sedation action, induce CYP’s

Question 4

how do barbiturates work

Answer 4

• bind to chloride channels and open them
• stabilise electric activity by raising the potential necessary for depolarisation
• targets the reticular activation system (which is responsible for epileptic activity) to decrease the electrical activity

Question 5

phenobarbital MOA/how they work & pentobarbital

Answer 5

• can be taken home, for home therapy
• induces CYP’s
• side effect sedation

pentobarbital

• a back up drug for when seizures are reoccuring (e.g if diazepam isnt working)
• very long lasting (more than diazepam)
• doesn’t work instantly however (diazepam is faster acting)
• can be dangerous as it causes significant sedation

Question 6

how to monitor when using these drugs

Answer 6

• animals are typically on these meds for life

- have to monitor blood concentration from time to time & always adjust doses

Question 7

general PK’s and PDs

Answer 7

• highly protein bound
• variable effects on CYP’s
• extensive hepatic metabolism occurs
• low, narrow therapeutic index