Anticonvulsants

Question 1

What does tonic mean in relation to seizures?

Answer 1

30 seconds
The animal will fall and become unconscious
Limbs are rigidly extended
Opisthotonos
Apnea

Question 2

What does clonic mean in relation to seizures?

Answer 2

1-2 minutes
Clonic limb movements in the form of running or paddling
Chewing movements of the mouth
Autonomic activity

Question 3

Why is it commonly recommended to spay bitches if they are epileptic?

Answer 3

Estrogen can lower the threshold for seizures, so we spay them to remove estrogen

Question 4

What is the goal in using an anticonvulsant in an animal prone to seizures? That is, why is completing stopping all seizure activity not attempted?

Answer 4

The goal is reduction in frequency of seizures: Duration of seizures, Severity of seizures
There is a risk for status epilepticus if you try to completely stop seizures

Question 5

CRIs of either diazepam or midazolam are sometimes used in refractory seizure cases while hospitalized. How do these two drugs differ relative to their binding to soft plastics such as IV bags and lines and their solubility in iv fluids?

Answer 5

Diazepam:
Absorbs to soft plastics
Limited solubility in most IV fluids

Midazolam:
Does not bind to plastics
Water soluble

Question 6

Know that diazepam, unlike in the dog, can be used in cats to prevent seizures. What type B adverse reaction in cats however is diazepam sometimes associated with if used repetitively?

Answer 6

Severe hepatitis

Question 7

What is bromide primarily removed by? Does it require a loading dose?

Answer 7

Kidney

Loading dose is necessary

Question 8

What is gabapentin primarily removed by? Does it require a loading dose?

Answer 8

Kidney

No loading dose

Question 9

What is levetiractem primarily removed by? Does it require a loading dose?

Answer 9

Kidney

No loading dose

Question 10

What is phenobarbital primarily removed by? Does it require a loading dose?

Answer 10

Liver

Loading dose is necessary

Question 11

What is zonisamide primarily removed by? Does it require a loading dose?

Answer 11

Liver

No loading dose

Question 12

Which anticonvulsant has the longest half-life in the dog?

Answer 12

Bromide (28 days)

Question 13

How should you stop treatment with phenobarbital?

Answer 13

Wean off drug, 25% decrease in dose every few weeks

Question 14

Know that you cannot abruptly stop phenobarbital in an animal that has been on it for a substantial period of time (months). In such cases the dose should be tapered over time.

Answer 14

25% decrease in dose every few weeks. Can discontinue ≤ 10 mcg/ml

Question 15

Why is primidone no longer recommended as an anticonvulsant in veterinary medicine? What related drug should instead be used?

Answer 15

More expensive and more likely to cause side effects than phenobarbital
Phenobarbital should be used instead

Question 16

How long does it take intravenous phenobarbital to reach its peak effect?

Answer 16

Maximum effect around 20 minutes post-dosing

Question 17

“Liver function tests” are often recommended for animals on chronic phenobarbital. Name two such tests.

Answer 17

Bile acids or ammonia challenge

Question 18

What endocrine test can show false results (indicate disease when it is not present) for animals receiving phenobarbital?

Answer 18

Thyroid testing

Question 19

Name the anticonvulsants appropriate for use in cats.

Answer 19

Oral Diazepam
Phenobarbital 
Zonisamide 
Gabapentin
Levetiractem

Question 20

Are benzodaizepines appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 20

Status epilepticus

Question 21

Is bromide appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 21

Maintenance

Question 22

Is gabapentin appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 22

Maintenance

Question 23

Is ketamine appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 23

Status epilepticus

Question 24

Is levitarcetam appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 24

Both

Question 25

Is phenobarbital appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 25

Both

Question 26

Is propofol appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 26

Status epilepticus

Question 27

Is zonisamide appropriate to break an on going seizure (status epilepticus), used to prevent additional seizures (maintenance), or both?

Answer 27

Maintenance

Question 28

What effect does diet have on the disposition of bromide?

Answer 28

Bromide comes in salts of potassium or sodium, so if you use potassium they should be on a sodium restricted diet and if you use sodium they should be on a potassium restricted diet

Question 29

What route(s) of administration is (are) used to give loading doses of bromide if the animal cannot receive it orally at that time?

Answer 29

Rectally

Question 30

What non-intravenous route(s) are used for owner to give diazepam or midazolam at home to stop an ongoing seizure?

Answer 30

Diazepam: rectal
Midazolam: intranasally (risk to owner) or IM. Potentially rectally but it’s not as effective as diazepam

Question 31

Bromide for anticonvulsant use must be compounded. Why is the dose different if using sodium bromide versus potassium bromide? Why are solutions of bromide preferred over capsules containing the crystals?

Answer 31

The dose of sodium bromide should be 15% less than the dose used for potassium bromide because there is a higher concentration of bromide in the sodium salt
With the solution, it is easier to adjust the dose, it is cheaper, and it is easier to give to the animal than capsules.

Question 32

Though classified as an anticonvulsant, name two other extra-label uses of gabapentin in cats.

Answer 32

Analgesic in neuropathic pain and manages aggression