serotonin related pharmacology

drugs that are used in behavioral pharmacotherapy work by...

alteration of neurotransmission activity in the brain (dopamine, norepinephrine, serotonin)

what behavior problems can we use pharmacotherapy to treat in animals?

-separation anxiety

-fears and phobias

-hyperactivity

-compulsive disorders

-cognitive dysfunction in older dogs

-house soiling in cats

what are the neurotransmitters of clinical importance in behavioral pharmacotherapy?

serotonin

dopamine

norepinephrine

(these are all monoamine neutrotransmitters, transmit the control and expression of emotions)

serotonin is especially important in what behaviors?

mood

feeding

reproductive behavior

norepinephrine is associated with what type of emotion?

alertness and focus

which neurotransmitter is related to mood, feeding, and reproductive behaviors?

serotonin

what neurotransmitter is important in regulating alertness and focus?

norepinephrine

which neutrotransmitter has a big role in cognitive functions, motivation, and awakeness?

dopamine

what type of functions does dopamine regulate?

Cognitive functions or brain activities: attention, memory, processing speed, and executive functions (i.e., reasoning, planning, problem solving, and multitasking).

motivation

awakeness

how do drugs increase the activity of monoamines (dopamine, serotonin, epinephrine)?

they block their reuptake, allowing their accumulation in the synapses

what are the most common drugs in treating behavioral problems in veterinary medicine?

antianxiety and antidepressant medications

serotonin (5-HT) is involved in the regulation of:

-mood

-feeding behavior

-sleep/wakefulness

-control of sensory pathways (including nociception)

-control of body temperature

-vomiting

-emotional behaviors (including aggression)

where in the body are serotonin receptors found?

enteric nervous system

CNS

how do selective serotonin reuptake inhibitors (SSRIs) work?

block the reuptake of serotonin, making more available in the synapse

they have little effect on the reuptake of norepinephrine

what drugs do we use in vet med that are in the category of selective serotonin reuptake inhibitors (SSRIs)?

Fluoxetine (prozac)

Paroxetine

Sertraline

Fluvoxamine

Citalopram

what type of drug is Fluoxetine (prozac)?

SSRI

what type of drug is paroxetine?

SSRI

what type of medication is sertraline?

SSRI

what type of drug is fluvoxamine?

SSRI

what drug is Citalopram?

SSRI

what are the clinical uses of SSRIs (Fluoxetine, Paroxetine, Sertraline, Fluvoxamine, Citalopram) in veterinary medicine?

obsessive disorders

phobias

aggression

separation anxiety

cats- fluoxetine and paroxetine are used for treating urine spraying, inappropriate urination, anxiety disorders, aggression, obsessive compulsive disorders

dogs- fluoxetine, sertraline, and citalopram are used to treat acral lick dermatitis, anxiety disorders, and obsessive compulsive disorders

what SSRIs are used in dogs?

fluoxetine

sertraline

citalopram

what SSRIs are used in cats?

fluoxetine

Paroxetine

what are the possible side effects of SSRIs in animals?

-mild sedation

-temporary lack of appetite

-anorexia

-increased anxiety

-decreased sexual motivation

-nausea and vomiting

the side effects are mild because these drugs are selective for serotonin receptors

why are SSRIs not commonly used in veterinary medicine?

because they are expensive, so we tend to use tricyclics instead

do SSRIs have severe side effects?

yes but mild. their side effects are mild because they are selective for serotonin receptors

which is the first choice and second choice in behavioral pharmacotherapy in vet med?

first- SSRIs

second- TCAs

but a lot of owners choose TCAs because they are cheaper

how do TCAs (tricyclic antidepressants) work?

inhibit the reuptake of serotonin and norepinephrine, potentiating their effects in the brain

which drugs only inhibit the reuptake of serotonin?

SSRIs

which drugs inhibit the reuptake of both serotonin and norepinephrine?

TCAs (tricyclic antidepressants)

which TCA is the most selective for serotonin?

clomipramine

what is the most used TCA in veterinary medicine?

Clomipramine

what is the use of Clomipramine in veterinary medicine?

used as an adjunct to behavior modification programs, especially in longstanding and severe anxiety

Cats: treatment of urine spraying, aggression, obsessive compulsive disorders

Dogs: treatment of separation anxiety, obsessive compulsive disorders, and to modify owner-directed dominance aggression

what type of drug is Clomipramine?

TCA

what is the main pharmacological effect of Clomipramine?

antidepressant (it inhibits the reuptake of serotonin)

what are the adverse reactions we can see with Clomipramine treatment?

anorexia, vomiting, diarrhea, lethargy, appetite changes, hepatobiliary disturbances

what medication is considered an "atypical" antidepressant?

Trazodone

what is Trazodone?

an "atypical" antidepressent that works as an agonist and antagonist for serotonin receptors- it is a weak serotonin reuptake inhibitor and a serotonin 5HT2A receptor antagonist

which antidepressant works as both a serotonin antagonist and agonist?

Trazodone

how do we administer Trazodone?

orally

which antidepressant has high binding to plasma proteins so has a risk of drug interactions?

trazodone

how is trazodone excreted?

urine

what are the adverse reactions possible with Trazodone?

Sedation, GI issues, Serotonergic syndrome (hyperthermia,

agitation, ataxia, hypertension, convulsions and

coma) when combined with other drugs that facilitate serotonin activity

what is serotonergic syndrome?

a result of elevated serotonin levels in the body

clinically, it presents as hyperthermia,

agitation, ataxia, hypertension, convulsions and

coma. it can even result in death if untreated.

the symptoms tend to appear quickly- within 10 min to 4 hours of taking the drug

this can be caused by high doses, mixing drugs that effect serotonin, high sensitivity to the drugs, and interaction with certain foods (cheese, turkey, red meat, bananas, peanut butter, anything with L-tryptophan)

what are the therapeutic applications of Trazodone?

dogs: treatment of mild thunderstorm phobia, as an adjunct to TCA or SSRI treatment (increases calmness, decreases agitation, and aids sleep), facilitating behavioral calming in dogs following

elective orthopedic surgeries

cats: treatment of travel anxiety and during veterinary examinations

what antidepressant can be used to calm cats during veterinary examinations?

Trazodone

what antidepressant can be used with TCA or SSRIs to increase the calming effect, decrease agitation, and aid with sleep?

Trazodone

what antidepressant is prescribed for treating mild thunderstorm phobia in dogs?

Trazodone

which drugs are monoamine oxidase inhibitors?

selegiline

how does selegiline work?

it is a monoamine oxidase inhibitor, so inhibits the metabolism of serotonin, norepinephrine, and dopamine. this increases the levels of all 3 neurotransmitters

what are the therapeutic applications of selegiline?

dogs: treatment of canine cognitive dysfunction syndrome (senility in older dogs)

not used in cats

which drug is useful for treating canine cognitive dysfunction syndrome?

selegiline

because it increases the amount of dopamine, which is useful for treating cognitive disorders