Unit 2- Anticonvulsants

Question 1

Anticonvulsants

Answer 1

Reduce frequency of neuron firing to block seizure initiation and propagation

Question 2

Anticonvulsant Metabolism

Answer 2

Metabolized too quickly in dogs, cats metabolize slowly and poorly

Question 3

Anticonvulsant MOA

Answer 3

Activate GABA Cl- channels, bind GABA A receptor, inactivate Na+ and Ca++ conductance

Question 4

Anticonvulsant Adverse Effects

Answer 4

Rapid cessation effect, liver and serum enzyme induction, and hepatotoxicity in dogs

Question 5

Barbiturate MOA

Answer 5

Phenobarbital, Pentobarbital, Primidone, activate GABA gated Cl- channels

Question 6

Benzodiazepine MOA

Answer 6

Diazepam, Midazolam, Clonazepam, and Lorazepam GABA A receptor agonists

Question 7

Hydantoin MOA

Answer 7

Phenytoin targets sodium channels

Question 8

Valproic Acid MOA

Answer 8

Acts via Cl- channels

Question 9

Gabapentin MOA

Answer 9

Synthetic GABA analog inhibiting voltage gated Ca++ channels

Question 10

Levatiracetam MOA

Answer 10

Binds to synaptic vesicle protein 2A

Question 11

Felbamate MOA

Answer 11

Unknown

Question 12

Zonisamide MOA

Answer 12

Inhibits Na+ and Ca++ channels

Question 13

GABA

Answer 13

Major inhibitory neurotransmitter, controls fear and anxiety, inhibits activity of neurons

Question 14

Phenobarbital

Answer 14

Produces anticonvulsant effect at lower doses than those needed to cause sedation

Question 15

Phenobarbital Uses

Answer 15

Long term seizure control

Question 16

Phenobarbital Adverse Effects

Answer 16

Sedation, PU/PD, polyphagia, dogs develop a tolerance to sedative effects

Question 17

Primidone

Answer 17

Metabolized to phenobarbital in dogs, not for use in cats

Question 18

Primidone Adverse Effects

Answer 18

Decreased serum albumin, elevated liver enzymes, and serious liver damage

Question 19

Pentobarbital

Answer 19

Terminates seizures at an anesthetic dose, used for status epilepticus

Question 20

Status Epilepticus

Answer 20

Seizure lasting longer than 5 mins or more than one seizure within 5 minutes

Question 21

Pentobarbital Adverse Effects

Answer 21

CNS Depressant, excitement during anesthesia recovery

Question 22

Benzodiazepine Uses

Answer 22

Anticonvulsants, tolerance is built up quickly in dogs, may be a maintenance anticonvulsant in cats

Question 23

Diazepam

Answer 23

Used in cats for seizure control, used in dogs for status epilepticus and cluster seizures

Question 24

Diazepam Adverse Effects

Answer 24

Changes in behavior, cats can develop acute fatal hepatic necrosis

Question 25

Midazolam

Answer 25

More potent than diazepam, used for status epilepticus, muscle relaxation, tranquilizer, and appetite stimulant, readily crosses BBB

Question 26

Midazolam Adverse Effects

Answer 26

Mild respiratory depression, vomiting, restless behavior and agitation, local irritation

Question 27

Clonazepam

Answer 27

Rapid development of drug tolerance

Question 28

Clonazepam Adverse Effects

Answer 28

Drug resistance, GI disturbance

Question 29

Lorazepam

Answer 29

Safely used in geriatric dogs and patients with liver disease, short term use in dogs, maintenance use in catss

Question 30

Lorazepam Adverse Effects

Answer 30

Increased appetite, anxiety

Question 31

Hydantoins

Answer 31

Impractical in dogs

Question 32

Valproic Acid

Answer 32

Controls seizures in dogs short term, not evaluated in cats

Question 33

Valproic Acid Adverse Effects

Answer 33

GI toxicity, hepatic toxicity, sedation, ataxia, behavioral changes, dermatologic effects, hematologic effects, pancreatitis, edema

Question 34

Potassium Bromide MOA

Answer 34

Enters neurons via Cl- channels to cause hyperpolarization

Question 35

Potassium Bromide

Answer 35

Takes months to achieve stable plasma combinations, used in combo with barbiturates and benzodiazepines to treat refractory seizures in dogs

Question 36

Potassium Bromide Adverse Effects

Answer 36

Transient sedation, GI toxicity, PU/PD, polyphagia, lethargy, irritability, aimless walking, pancreatitis, asthma in cats

Question 37

Gabapentin Adverse Effects

Answer 37

Sedation, ataxia, polyphagia, can cause seizures after rapid discontinuation

Question 38

Levetiracetam

Answer 38

Used for refractory canine epilepsy

Question 39

Levetiracetam Adverse Effects

Answer 39

GI disturbance, changes in behavior, drowsiness, may cause seizures after rapid disruption

Question 40

Felbamate

Answer 40

Used for patients with local and generalized seizure, used in brain tumor or cerebral infarct

Question 41

Felbamate Adverse Effects

Answer 41

Liver dysfunction, bone marrow depression, generalized tremor, dry eye

Question 42

Zonisamide

Answer 42

Used for patients with local and generalized seizures, useful in brain tumor or cerebral infarct