CNS (Anxiolytics/Antidepressants) - NICOLE

Question 1

do you need to taper CNS drugs?

Answer 1

YES!

Question 2

behaviour modifying drugs the potential to result in

Answer 2

aggression

Question 3

behaviour modifying drugs generally take ___________ ___________ to exert their full effect

Answer 3

several weeks - neurotransmitters adapt slowly to treatment

Question 4

examples of anxiolytic drug classes

Answer 4

benzodiazepines
azopirones
antihistamines
barbiturates

Question 5

examples of benzodiazepines

Answer 5

diazepam, midazolam

Question 6

are benzodiazepines analgesics ????

Answer 6

NO

Question 7

benzodiazepines clinical effects

Answer 7

-anxiolytic
-sedative and hypnotic at higher doses
-anterograde amnesia (good for pre-anesthetic, bad for long-term behaviour)
-muscle relaxant
-anticonvulsant
-appetite stimulant
-respiratory depressant

Question 8

should you give oral diazepam to cats?

Answer 8

no - hepatic necrosis

Question 9

different effects of benzodiazepines are due to

Answer 9

variations in the GABA receptor

Question 10

benzodiazepines- chronic administration can cause

Answer 10

GABA receptor down-regulation

Question 11

can you get tolerance to benzodiazepines

Answer 11

yeah boiiiii as soon as 1 week after chronic administration

Question 12

when administering benzodiazepines do you need to gradually taper

Answer 12

chronic administration to prevent discontinuation syndrome - nervousness, tremors, seizures

Question 13

what is an excellent sedative for small ruminants (especially goats)

Answer 13

diazepam - has a better safety profile than xylazine
however DOESNT PROVIDE ANALGESIA

Question 14

midazolam - can it be given IM?

Answer 14

yes - DIAZEPAM CANNOT

Question 15

Buspirone - the only clinically relevant

Answer 15

azapirone - but not licensed in vet med in Canada

Question 16

serotonin is very important bc

Answer 16

regulates sleep, sensory perception, cognition, motor activity, appetite, intestinal motility, temperature regulation, mood, and behaviour

Question 17

many hallucinogens have structures similar to

Answer 17

serotonin

Question 18

there are many different subtypes of serotonin receptors - most are

Answer 18

G protein coupled

Question 19

are serotonin receptors presynaptic or postsynaptic

Answer 19

either

Question 20

the 5-HT1A receptor can get sensitized by

Answer 20

buspirone and SSRIS

Question 21

buspirone is used for

Answer 21

fear/poor socialization in cats
- causes increased friendly behaviour and reduced anxiety and doesn’t affect memory, so animal learns behaviour

Question 22

behavioural effects of buspirone seen after

Answer 22

1-4 weeks of regular administration

Question 23

examples of antidepressants

Answer 23

-selective serotonin reuptake inhibitors (SSRIs)
-Tricyclic antidepressants
-monoamine oxidase inhibitors (MAOs)
-atypical antidepressants

Question 24

how do antidepressants work (very general)

Answer 24

generally potentiate (ether directly or indirectly) the actions of serotonin and/or norepinephrine in the brain

Question 25

antidepressants take how long to work

Answer 25

several weeks to see full effects

Question 26

antidepressants work best if combined with

Answer 26

behavioural therapy

Question 27

how to dose antidepressants

Answer 27

-start at low end of dose and assess response to minimize adverse effects -wait an appropriate amount of time between dose adjustments (generally at least 2 weeks) - CAN TAKE 4-6 WEEKS to see full response

Question 28

examples of SSRIs

Answer 28

fluoxetine (most important), paroxetine, sertraline

Question 29

SSRIs are antidepressants with what effects

Answer 29

anxiolytic, anti compulsive, and anti-aggressive effects

Question 30

SSRIs work by

Answer 30

blocking the reuptake of serotonin, making more available at the synapse. VERY SELECTIVE - competitive inhibitors of cytochrome P450 enzymes which may lead to increased concentrations of drugs metabolized by cytochrome P450 enzymes

Question 31

SSRIs effect on blood glucose levels

Answer 31

can lower blood glucose levels, so use with caution in diabetic patients

Question 32

is there a relationship between SSRI plasma concentrations and clinical effect?

Answer 32

very little relationship

Question 33

should you discontinue SSRIs gradually

Answer 33

ya

Question 34

Fluoxetine is also known as

Answer 34

prozac

Question 35

use GREAT CAUTION if combining fluoxetine with

Answer 35

monoamine oxidase inhibitors (MAOIs) as this can lead to serotonin syndrome

Question 36

serotonin syndrome occurs when

Answer 36

excessive stimulation of serotonin receptors results in muscle rigidity, myoclonus, salivation, agitation, and hyperthermia. It is more likely to occur if 2 SSRis are used together or and SSRI is combined with a MAOI. CAN BE FATAL

Question 37

tricyclic antidepressants examples

Answer 37

clomipramine (more important) and amitriptyline

Question 38

tricyclic antidepressants work by

Answer 38

inhibiting serotonin and norepinephrine reuptake - also have anticholinergic and antihistaminic effects

Question 39

tricyclic antidepressants (TCA) have what effects

Answer 39

antidepressant, anxiolytic, anticompulsive, and antiaggressive

Question 40

TCA mechanism of action

Answer 40

block NE and serotonin re-uptake

Question 41

adverse effects of TCA are due to

Answer 41

lack of receptor specificity

Question 42

adverse effects of TCA

Answer 42

sedation, miosis, urinary retention, + others related to anticholinergic effects

Question 43

clomipramine is approved for use in

Answer 43

dogs for obsessive compulsive disorder and for dominance aggression & separation anxiety

Question 44

when using clopramine, what do you need to do

Answer 44

increase & decrease doses gradually - know cats metabolize it more slowly than dogs & require a lower dose - know there's a narrow therapeutic index - overdoses can be life threatening

Question 45

Trazadone is an atypical antagonist - it works by

Answer 45

serotonin antagonist and reuptake inhibitor

Question 46

trazadone effects

Answer 46

antidepressant, anxiolytic, hypnotic (sleep-inducing) - used as anxiolytic prior to vet appointments in nervous dogs and cats +/- gabapentin

Question 47

trazadone antagonizes which serotonin receptors

Answer 47

ALL except 5-HT1a - at low doses primarily acts as a 5HT2a antagonist, which is associated with neuronal excitation, anxiety, and learning

Question 48

Monoazmine Oxidase is a mitochondrial enzyme found in the

Answer 48

NS, heart, liver, kidneys, spleen, platelets with 2 diff types -MAO-a and MAO-B

Question 49

in the CNS, MAO-B catalyzes the oxidative deamination of

Answer 49

catecholamines, including dopamine, norepinephrine, epinephrine, 2-phenylethylamine, and serotinin

Question 50

MAOIs inhibit the oxidative deamination of hormones/neurotransmiters listed in last question, which means

Answer 50

more neurotransmitters are available

Question 51

example of MAO-B inhibitor

Answer 51

selegiline - used to treat cognitive dysfunction in older dogs