Behaviour Modifying Drugs Flashcards
what are the 5 key neurotransmitters for behaviour modification
- NE
- dopamine
- serotonin
- GABA
- acetylcholine
T/F the current drugs used to modify behaviour in vetmed are extra-label use of human drugs
T
what is the effect of behaviour modifying drugs on behaviour modifying techniques
it can decrease latency to responses
what are the two types of aggression? which is more common and which is more of a concern?
offensive and defensive; offensive more of a concern but defensive more common
what are some subtypes of aggression
- fear
- dominance
- territorial
- possessive
- maternal
drugs that do what can reduce aggression
drugs that increase central serotonergic activity
what general category of drugs (3) can reduce compulsive behaviour
TCA’s, SSRIs, opioid antagonists
what types of drugs can help fear/anxiety/phobias
anxiolytics
treatment of behaviour disorders with drugs will vary in duration with:
- drug class
- the individual/species
- the unwanted behaviour
- the owner’s compliance
how are most behaviour modifying drugs given (constantly or as needed)
most are NOT given as needed
how do we ideally want to manage behaviour modifying drug dosage
gradually reduce (taper) the dose based on the animals response; identify the lowest effective dose
what is an important consideration re. pharmacokinetics and pharmacodynamics if you think a behaviour modifying drug is not working
It takes time! approx 5 half-lives before reaching steady state; receptor modification also takes time
what can you do if the behaviour modifying drug is not working
- adjust dose (consider ADRs)
- switch drug class
- combination drug therapy
Are behaviour modifying drugs good transdermal
N
many behaviour drugs used in vet med are weak (acids/bases)
what does this mean?
bases
- good lipophilicity
- low protein binding
- good CNS penetration
most behaviour drugs are metabolized by
liver
what are the principal anxiolytics in vetmed
benzodiazepines
how do benzodiazepines work? where is the anxiolytic effect coming from
stimulate GABA-A receptors; believed that the anxiolytic effect is due to modulation of 5-HT and NE neurons in the CNS
T/F the anxiolytic effects of benzos can be immediate and increase with dosing
T
what is the use of benzodiazepines for anxiolysis
separation anxiety and general anxiety
why should we avoid using benzodiazpines in aggressive dogs
can cause disinhibition
what are some potential adverse effects of benzodiazepines as an anxiolytic drug
what can we use to reverse these effects
- disinhibition
- excitement and amnesia
- hepatotoxicity in cats with diazepam
- sedation
- mm relaxation
- ataxia
- hyperphagia
flumazenil
is the half life of diazepam higher in dogs or cats and what does that mean
cats (5.5h vs 1h in dogs); can be used chronically in cats only
what are some caveats of diazepam as a behaviour modifying drug
disappointing for immediate effects; daily use better than as needed use; may need higher doses in panic states
what is a benefit of alprazolam over diazepam
more potent so it produces better results in dogs with panic disorders where a rapid response is needed
what is a benefit of lorazepam over alprazolam and diazepam
lower hepatic metabolism before excretion, making it better for liver dz patients, geriatric patients, and cats
what is the MoA of buspirone
5-HT receptor partial agonist
what is the use of buspirone
for generalized anxiety
what are the pros and cons of buspirone
pros:
- less sedation and side effects vs BZDs
- less abuse potential
- no withdrawal
cons:
- poor immediate effects
the general category of antidepressants includes many classes of drugs including:
- selective serotonin re-uptake inhibitors: SSRIs
- tricyclic antidepressants: TCAs
- monoamine oxidase inhibitors: MAOI
what is the general property (effect) of all antidepressants
altering NE and 5-HT levels in the CNS
what is the MoA of tricyclic antidepressants
inhibit 5-HT and NE re-uptake in the CNS (produces the anxiolytic and decreased arousal)
also anticholinergic and antiadrenergic effects
some also inhibit histamine receptors
what are some ADRs associated with tricyclic antidepressants
- CVS effects
- GI effects
- urinary effects
- sedation
when are tricyclic antidepressants contraindicated
- KCS
- glaucoma
what is a benefit of tricyclic antidepressants over BZDs
tricyclic antidepressants do not produce disinhibition
what is the MoA of clomipramine
primarily blocks 5-HT re-uptake but a metabolite (desmethyl clomipramine) blocks NE re-uptake
what are the uses of clomipramine (4)
- anti-anxiety
- treatment of stereotypies
- storm and noise phobias
- aggression
what is the MoA of amitriptyline
more selective for 5-HT re-uptake over NE reuptake
both decreased arousal/calming and pain management
what is the most common use of amitriptyline in cats
idiopathic interstitial cystitis
T/F SSRIs are classified as anti-depressants but display a wide array of effects
T
what are the main safety concerns with SSRIs
generally considered very safe
- anorexia and sedation
- serotonin syndrome
serotonin syndrome is more likely when SSRIs are combined with:
- 5-HT agonists
- TCAs: also decrease 5-HT reuptake
- MAOI: decrease SSRI metabolism
- OTC herbal supplements
what is the MoA of fluoxetine
5-HT reuptake inhibition
fluoxetine is metabolized to
norfluoxetine
what are the consequences of fluoxetine metabolism to norfluoxetine
creates a 6 week washout as norfluoxetine is an active metabolite; there is a long elimination half-life of both drugs as accumulation occurs with multiple doses
T/F transdermal fluoxetine exists
T but poor and variable bioavailability
what is the idea behind opiate receptor antagonists for behaviour disorders
believed that some stereotypies are a coping mechanism that is reinforced by endorphin release; these drugs block that reinforcement by blocking the opioid receptor
what is naltrexone and what are its pros and cons
opiate receptor antagonist; expensive; not a controlled substance
what is the MoA of antipsychotics
inhibit dopamine D2 receptors
what are pros and cons of antipsychotics
pros:
- quieting
- transquilizers
cons:
- inhibit learning
- lower bp
- sedation
- extrapyramidal effects
- ataraxia
- poor anxiolytics
what are some examples of low potency antipsychotics
acepromazine, chlorpromazine
what are the major side effects of acepromazine and chlorpromazine
greater cholinergic (sedation) and a-adrenergic (hypotensive) blocking effects
when are acepromazine and chlorpromazine mainly used
as needed for noise and thunderstorm phobia (max effect 1h after dosing)
what is the MoA of medroxyprogesterone acetate
acts on GABA-A receptors, increases endogenous opioid release, stimulates central steroid receptors
what are the uses of medroxyprogesterone acetate
mostly in males to reduce aggression, urine marking and roaming
what are some adverse effects of medroxyprogesterone acetate
- mammary enlargement
- BM suppression
- diabetes mellitus
- addisons dz
- liver damage
- hyperphagia
where are pheremones extracted from in dogs and in cats
dogs: intermammary sebaceous gland
cats: facial pheremone glands
how can anticonvulsants be used to manage behaviour? name 3 examples
behaviour with a neurological basis only
- gabapentin
- trazadone
- dexmedetomidine
what is the MoA of trazadone and how is it used
5-HT and NE reuptake inhibition; used for thunderstorms and as an adjunct for TCA and SSRI treatment
