Pharm of Behavior-Modifying Drugs

Question 1

Function of Monoamine Oxidase (e.g., Anipryl)

Answer 1

Breaks down monamine NTs - canine cognitive dysfunction syndrome

Question 2

MoA of Selegiline, a Monoamine Oxidase-B (MAO-B)

Answer 2

Selegiline = MAO INHIBITOR — STOPS breakdown of NTs like serotonin

Question 3

Clinical effects of Selegiline

Answer 3

Stops breakdown of NTs -> improves sleeping patterns, house-soiling frequency, activity levels; improved spatial memory in dogs

Question 4

What can and can’t Selegilline be combined with?

Answer 4

CAN: benzodiazepines, anticonvulsants
CAN’T: SSRIs (at least 2 weeks!), other MAO-Is, Alpha-2 agonists

Question 5

Tricyclinc anti-depressants (TCAs) MoA?

Answer 5

SNRIs (serotonin and norepinephrine re-uptake inhibition), Alpha-1 adrenergic receptor antagonist. Anti-histaminic (drowsiness)

Question 6

What is Clomipramine? Used for what?

Answer 6

A TCA class drug. Used in separation anxiety in dogs > 6 months old.

Question 7

Venlafaxine?

Answer 7

SNRI for cats - fear, aggression, house-soiling

Question 8

Common side effects of SNRIs, SSRI, TCAs

Answer 8

GI effects, lower seizure threshold, insomnia

Question 9

Drug class of Fluoxetine? On-label and off-label use?

Answer 9

SSRI
On-label = separation anxiety in dogs
Off-label = behavior modification

Question 10

Inhibition of serotonin and norepinephrine (SNRI) has what function? Functions of each NT?

Answer 10

Anxiolytic (reduce anxiety)
- Norepinephrine = fight/flight (amygdala activation)
- Serotonin = (regulate mood, sleep, body temp)

Question 11

What is serotonin syndrome? Antidote?

Answer 11

Excess [serotonin] -> TACHYCARDIA, HYPERTENSION, HYPERSALIVATION, AGITATION; TREMORS, SEIZURES

Antidote = Cyproheptadine (serotonin antagonist - blocks 5-HT2A receptor with no action -> increase circulation of serotonin)

Question 12

SSRI drug function

Answer 12

sympathomimetic drug -> increase serotonin release

opposite: acepromazine blocks serotonin receptors

Question 13

SARI - function & most common drug?

Answer 13

Serotonin Antagonist and Re-uptake Inhibitor - antagonize 5-HT2A receptor & alpha-1 adrenergic antagonist, + inhibit re-uptake of serotonin & norepi. –> increase circualtion of serotonin + norepi
ANTI-DEPRESSANT!
Antihistamine (drowsiness)

TRAZODONE!! (side effect = drowsiness)

Question 14

When to use a calcium channel blocker like Gabapentin?

Answer 14

When PAIN is a suspected component of pt’s anxiety. Potentiates effects of alpha-2 agonists.

Question 15

Function of Alpha-2 agonists?

Answer 15

inhibit release of norepi, ACh -> decreased sympathetic tone. NO analgesic effects!

Question 16

Benzodiazepine MoA? Use for anxiety?

Answer 16

Prevent GABA dissociating from receptor -> Cl channel stays open // influx of Cl-

Situational anxiety!

Question 17

Why should you not use Acepromazine by itself?

Answer 17

Causes sedation, BUT IS NOT AN ANXIOLYTIC!!

Question 18

Why should Chlorpromazine not be used in horses?

Answer 18

Horse can experience agitation, excitement -> horse loses balance and falls over -> dangerous for surrounding people + horse can injure themselves

Question 19

Why should Fluphenazine not be used in horses?

Answer 19

Can have severe paradoxical reactions (sweating, agitation, circling, severe stupor episodes!, aggression!!!)

Question 20

Why should Reserpine not be used in horses?

Answer 20

Use: sedative, agalactia
COLIC! GI upset.
Severe hypotension (anesthesia).

If given for sedation, do PO, not IM (prolonged effects)

Question 21

Which drugs block the serotonin type 2A receptor?

Answer 21

SARIs (trazodone, cyproheptadine)