Antiepileptic Drugs (Final)

Question 1

Define seizure

Answer 1

clinical manifestation of abnormal electrical activity in the brain

Question 2

Define epilepsy

Answer 2

seizures that occur intermittently over months to years for which a contributing underlying cause cannot be identified

Question 3

Define Status Epilepsy

Answer 3

repeated seizures without full recovery between them, or a single seizure that lasts more than 5 minutes

Question 4

Define Cluster Seizure

Answer 4

more than one seizure occurring within a 24 hour period with recovery in between

Question 5

What are the 4 mechanisms of action of antiepileptic drugs?

Answer 5

• increase inhibitory neurotransmitters: GABA
• decrease excitatory neurotransmitters: glutamate
• block voltage-gated inward positive currents: Na+ or Ca++
• increase outward positive current: K+

Question 6

What is used for acute therapy?

Answer 6

• IV Benzodiazepines (Diazepam)
• IV Phenobarbital
• IV Propofol

Question 7

Phenobarbital

• class of drug
• type of drug
• administration
• metabolism

Answer 7

• barbiturate
• GABAa potentiator, for chronic use
• PO, but IV available
• metabolized by the liver
• potent inducer of hepatic microsomal enzymes

Question 8

Phenobarbital Cautions

Answer 8

• PU/PD/PP
• sedation
• elevated liver enzymes
• paradoxical hyperexcitability

Question 9

Bromide

• use
• class, formulations
• administration
• cautions

Answer 9

• primary or add-on anticonvulsant in dogs
• salt/chemical powder
• oral only, very long half life
• GI upset, sedation, toxicity in overdose
• do not use in cats: asthma-like conditions

Question 10

Zonisamide

• type of drug
• administration
• class
• cautions

Answer 10

• second or third-line anticonvulsant
• oral
• sulfonamide derivative
• low overall toxicity

Question 11

Levetiracetam

• type of drug
• administration
• half life, excretion
• cautions

Answer 11

• second or third-line anticonvulsant
• oral and IV
• very short half life
• excreted unchanged in urine
• sedation/ataxia in dogs
• inappetence/salivation/lethargy in cats

Question 12

Imepitoin

• type of drug
• administration
• half-life, absorption
• adverse effects

Answer 12

• anticonvulsant, partial benzodiazepine agonist
• PO only
• slow but absorbed well orally
• short half life
• minimal adverse effects: PU/PD/PP, hyperactivity, somnolence, GI signs