Anticonvulsants Flashcards
(15 cards)
Diazepam
- Drug class
- MOA
- Treatment or prevention?
- Safety?
Anticonvulsant
- Benzodiazepine
- MOA - GABA agonist
- Seizure treatment
- Very safe - no impacts on CVS
Phenobarbitone
- Drug class
- MOA
- Treatment or prevention?
- Important to do regular follow up tests, why?
- Side effects
- Can mask what?
Anticonvulsant
- Barbiturate
- MOA - decrease CNS excitability via GABA agonism (open Cl channels to hyperpolarize the cell) - Stabilizes electrical activity by raising the potential necessary for depolarisation
- Seizure prevention
- Important to do regular follow up tests, why?
1. Induces hepatic metabolism of itself - liver gets better at metabolizing it = break through seizures
2. Can be hepatotoxic - can start destroying structure of liver
- Side effect - Sedation
- Can mask non-idiopathic causes of epilepsy eg. infectious
Pentobarbitone
- Drug class
- Its main use
- Anticonvulsant use
- BUT?
Anticonvulsant
- Barbiturate
- Euthanasia solution
- Main use as an anticonvulsant is for refractory seizures not responding to IV diazepam –> VERY RISKY!
- BUT - does not have the highly selective anti-seizure activity of phenobarbitone so will reduce seizure activity WITH significant sedation
Propofol
- Treatment or prevention?
- Why used?
Anticonvulsant
- Seizure treatment
- Dose to effect to accommodate patients that require very deep sedation/Anaesthesia to prevent seizures
Potassium bromide
- Treatment or prevention?
- What is it used alongside? and why
Anticonvulsant
- Seizure prevention
- Used alongside phenobarbitone - used a dose sparing effect - for breakthrough seizures - dose lowering effect on phenobarbitone
Levetiracetam (“Kepra”)
- Treatment or prevention?
- Side effects?
- Administration?
- Loading dose?
Anticonvulsant
- Seizure prevention
- Very few!
- IV, IM, PO
- Shorter 1/2 life = no loading dose recquired!
Gabapentin (“Neurontin”)
- Treatment or prevention?
Anticonvulsant
- Seizure prevention
- MOA poorly understood - possibly blockade of pre-synaptic Ca channels
Imepitoin (“Pexion”)
- Treatment or prevention?
- MOA
- Combined with?
- Tolerance
Anticonvulsant
- Seizure prevention
- MOA - partial agonist at the benzodiazepine receptor - even safer than diazepam
- Can be combines with phenobarbibtone
- No drug tolerance - big difference to benzodiazepines!!
What is a seizure?
What is epilepsy?
What is ictal?
- Seizure: Sudden depolarisation of a group of neurons leading to an abnormal synchronous electrical discharge from the CNS
- Epilepsy: The condition associated with multiple unprovoked seizures
- Ictal: The physiological event itself
pre- / intra- / inter- / post-ictal –> The before, during, between and after of a seizure
Name 4 causes of seizures
- Idiopathic
- Infectious (toxoplasmosis, neosporosis, cryptococcosis)
- Neoplasia
- Toxins (snail pellet, snake bite, strychnine)
Explain anticonvulsant therapy
Stabilise membranes of neurons to prevent the unwanted depolarisation of the neuron that is manifesting as a seizure
Name the 3 main drugs used in private practice for seizure TREATMENT
- Diazepam
- Phenobarbitone
- Pentobarbitone
Name the 3 main drugs used in specialist practice for seizure TREATMENT
- Benzodiazepine (diaz or midaz) +/- phenobarbitone
- CRI propofol
Name the 3 main take home oral used for seizure PREVENTION
- Phenobarbitone
- KBr
- Levetiracetam/Gaba/Imepitoin
Select the concern that may arise
if an animal is started on an anticonvulsant (to prevent seizures) without first performing a series of diagnostic tests.
a. Breakthrough seizures are more likely.
b. It is more difficult to determine a starting dose of the anticonvulsant.
c. An effective anticonvulsant could mask a cause of seizures that is treatable without anticonvulsants.
d. Higher doses are likely to be needed.
e. Stronger, and less safe, anticonvulsants will be needed.
c. An effective anticonvulsant could mask a cause of seizures that is treatable without anticonvulsants.
