Animal Behaviour - Psychopharmacological Agents Used in Practice
Drug therapy in animal behaviour is advocated when behavioural responses are extreme, deeply ingrained, or occur at very low thresholds, making behavioural therapy difficult to initiate. It is also used when there's a strong organic basis (e.g. neurological disorders) or when rapid improvement is necessary to maintain client motivation and compliance.
When would drug therapy be advocated?
Behavioural response extreme and well established
Difficult to start any form of behavioural therapy due to response at a low threshold
Strong ‘organic’ component (eg. neuro pathologies)
Rapid changes are needed for client compliance/motivation
Key Terms
When would drug therapy be advocated?
Behavioural response extreme and well established
Difficult to start any form of behavioural therapy due to response at a low threshold
What 3 things should be considered when thinking about drug use?
Possible side effects/costs/risk of misuse v pros.
Owner aware that drugs are an adjunct not alternative?
Non-specific action of drugs ...
Why is off-label drug usage common with behavioural drugs?
Few licensed in the species we need them for.
ensure sufficient quality scientific evidence to support use
ensure owner has given infor...
What are the six main NTs behavioural drugs will work on?
Ach (Achetylcholine)
DA (Dopamine)
NA (Noradrenaline)
GABA (Gama-aminobutyric acid)
5-HT (Serotonin)
Melatonin
List the 8 classes of anxiolytic drug
Benzodiazepenes
B Blockers
Azapirones
Barbituates
Antihistamines
Tri-Cyclic Antidepressants (TCAs)
Selective se...
List the anxiolytic medications useful for SHORT TERM use.
Benzodiazepenes (Diazepam, Alprazolam)
- B Blockers (Propanolol)
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
When would drug therapy be advocated? | Behavioural response extreme and well established Difficult to start any form of behavioural therapy due to response at a low threshold Strong ‘organic’ component (eg. neuro pathologies) Rapid changes are needed for client compliance/motivation |
What 3 things should be considered when thinking about drug use? | Possible side effects/costs/risk of misuse v pros. Owner aware that drugs are an adjunct not alternative? Non-specific action of drugs -> Disinhibitoin risk? |
Why is off-label drug usage common with behavioural drugs? | Few licensed in the species we need them for. ensure sufficient quality scientific evidence to support use ensure owner has given informed written consent use in accordance with published guidelines |
What are the six main NTs behavioural drugs will work on? | Ach (Achetylcholine) DA (Dopamine) NA (Noradrenaline) GABA (Gama-aminobutyric acid) 5-HT (Serotonin) Melatonin |
List the 8 classes of anxiolytic drug | Benzodiazepenes B Blockers Azapirones Barbituates Antihistamines Tri-Cyclic Antidepressants (TCAs) Selective serotonin reuptake inhibitors Monoamine oxidase inhibitors |
List the anxiolytic medications useful for SHORT TERM use. | Benzodiazepenes (Diazepam, Alprazolam) - B Blockers (Propanolol) |
List the anxiolytic medications useful for LONG TERM use. | Azapirones (Buspirone) TCAs (Amytriptaline, clomipramine (Clomicalm), Imipramine, Doxepin, Desiprsamine, Nortriptyline SSRIs (Fluoxetine (Prozac), Paroxetine (Paxil), Sertraline (Zoloft), Citalopram, Fluvoxamine) MAO inhibitors (Selegiline, MAO-B inhibitor) |
What is another name for Diazepam? What is it commonly used for? | Valium Seizure medication in dogs and cats |
What is the main effect of the benzodiazepines? | Facilitate the INHIBITORY effect of GABA in the CNS -> dampen excitation in the brain |
Why are benzodiazepines well formulated to affect the CNS? What repercussions does this have? | They are highly lipophilic. Pharmacokinetics/dynamics affected depending on obesity level of dog - fat dog -> absorption and slow release - skinny dog -> rapid ^conc and then vconc |
What side effects are associated with benzodiazepines and how soon is their onset? | Very quick onset sedation ataxia mm relaxation ^apetite esp in cats paradoxical excitement in 10-20% cases memory deficits hepatic necrosis in cats (rare) |
Why are benzodiazepines not good to give in conduction with behaviour therapy? | Block consolidation of memory so will not learn new things |
How might these effects change with time? | Tolerance to sedation and ataxia after a few days |
How can these side effects be predicted? | Give test doses to evaluate reaction |
What are benzodiazepines useful for in behavioural medicine? | Anxiolytic Amnesic if given ~1 hour before event |
What are the potential problems associated with benzo use? | Disinhibition of aggression Interference with learning Risk of fatal liver failure in cats Human abuse potential Addictive properties/dependence Teratogenic properties Drug interactions |
How should benzos be stopped? | Gradually - suddenly stopping -> recurrence, extreme nervousness, seizures |
What is the half life of diazepam in dogs? | Hours (v short) |
What is the greatest risk associated with the use of diazepam in cats? Other risks? | Hepatic necrosis Reduced depth perception (do not let outside!) Apetite stimulant |
What is the efficacy of diazepam like? | Varied - dose adjusted to effect Sometimes dose required causes unacceptable level of ataxia |
How does alprazolam compare to diazepam? | Higher potency Better retrograde amnesia (NB: no anxiolytic effect until given obviously) Longer half life - 12 hrs, peak levels in 1-2hrs Increased friendliness in cats (but still loss of depth perception and ataxia) |
How do B-blockers work? | Selective blocking of b1 and/or b2 adrenergic receptors in myocardium, bronchi and vascular smooth muscle Reduced sympathetic response in a fearful situation -> v feeling of anxiety feedback loop Possibly also central activity |
When would B-Blockers be useful in a behavioural therapy programme? | When animal is too hyper-reactive to even begin training. Only mild anxiolytics but no cognitive impairment |
What are the potential side effects of B-blockers? | Bradicardia Hypotension Lethargy Depression Hypoglycaemia Bronchoconstriction Syncope Diarrhoea |
What is syncope? | Fainting |
Where are B-blockers contra-indicated? | Hypotension Heart failure Bronchospastic disease Bradycardia |
What type of drug is Propanolol? | Non-selective B-blocker (b1+b2) | Metabolised in liver |
What is the half life of propanolol in dogs? | 0.77-2hours |
What four mechanisms of actions do azapirones have? | Serotonergic, noradrenergic, dopaminergic and cholinergic | "Dirty" |
What is the only azapirone used in behavioural therapy? | Buspirone |
What is buspirone's main mechanism of action? | Partial 5-HT1a agonist at PRE and POST synaptic receptors. | Mixed ag/ant properties on DA receptors |
How is buspirone excreted? | Inactive metabolite in the urine |
Why will buspirone have varying effects in individual animals? | As it acts on PRE and POST synaptic receptors, effects will depend on number of receptors in individual animal. if more PRE synaptic receptors to be affected, will DEcrease activity if more POST synaptic receptors to be affected, will INcrease activity |
How and why do effects of buspirone differ in the short and long term? | Short term: ^ likelihood of 5-HT impulses | Long term: Downregulation of post synaptic receptors -> v likelihood of 5-HT impulses |
How commonly is buspirone used? | RARELY some success reported in feline spraying but high relapse rate, no placebo controlled trials poor efficacy in specific fears |
How quickly does Buspirone act? | Slow onset of action (1-3 weeks) | Short half life - BID/TID |
What are the side effects of buspirone? | GI disturbance, irritability, ^aggression, paradoxical excitability, humans - headaches, dizziness, insomnia, bradycardia, cramps, stereotypic behaviours |
What makes buspirone a good choice of drug? (despite not commonly used) | Wide safety margin No sedative/hypotic effect No withdrawal phenomenon No abuse potential |
Give examples of TCAs | Amitryptaline Clomipramine (licensed for dogs) Imipramine Doxepin Desipresamine Noritryptaline |
How do TCAs work? | Block reuptake of 5HT and NA (different compounds block each to a different degree) Most have active metabolites |
Which behaviour problems are TCAs advocated for? | Wide variety - compulsive disorders, separation anxiety, urine marking |
How long does it take for TCAs to reach therapeutic levels? | Long time - 2-4 weeks |
What are the side effects of TCAs and when do they begin? | RAPID ONSET (despite therapeutic action slow onset) mild transient sedation Anticholinergic effects (urinary retention, constipation, dry mouth) Antihistiminic effects - Hypotension, motor incoordination, cardiac conduction disturbance (in healthy animals this is not pathological), agranulocytosis (rare) |
When may the antihistaminic effects of TCAs be useful? Which TCA is particularly antihistaminic? | Itching/scratching based problems Cystitus amytriptaline good |
Which two drugs should NEVER be given together? | Clomipramine and Selegeline inexact with MAObs -> SEROTONIN SYNDROME hyperthermia, rigidity, myoclonus, confusion, delerium, coma - fatal |
What conditions are TCAs contraindicated for? | Heart disease Hypertension Hypothyroidism Epilepsy (lowers seizure threshold) Concurrent use with MAOBs Other potential problems - bitter taste - potential for human misuse - OD fatal with no antidote |
When is amitryptaline usually used? | Greater NA and H1/2 effects required FLUTD (although beware urine retention due to Anticholinergic side effects) Pyschogenic alopenia ALD in dogs |
What is the most common use of Clomipramine? | Clomicalm - licensed for separation anxiety in dogs multi centre, palcebo controlled, blinded trial Main effect 5HT used in cats off label but tolerated less well than dogs, side effects worse and more variable |
Give examples of` SSRIs | Fluoxetine (Prozac) Paroxetine (Paxil) Sertraline (Zoloft) Citaloproam Fluvoxamine (also NA effects -> anxiety) |
What are SSRIs most commonly used for? | Fear responses - sudden, immediate and unconsidered, sometimes anxiety sometimes compulsive disorders |
Which response is NA responsible for? | Panic/stress |
What is serotonins role? | Anti depressive, antianxiety |
What is the time until therapeutic onset of SSRIs? | Long - 3/4 weeks |
What may occur with short term SSRI use? | ^anxiety due to v 5HT (negative feedback of serotinergic auto receptors) with longterm use v anxiety due to receptor (up?) regulation and ^ [5HT] |
How may the initial antigenic properties of SSRIs be combatted? | Short course benzodiazepenes |
Where other than the CNS are serotinergic pathways found? How does this impact side effects? | The gut -GI irritability (can be reduced by gradual increase of dose) |
What other side effects of SSRIs? | Insomnia, sedation, potential for human misuse |
Which SSRI is licensed for separation anxiety? | Fluoxetine "Reconcile" (USA) long half life active metabolite rapid onset side effects GI irritation, inappetance , lethargy, nervousness |
What kind of molecule are all NTs? | Monoamines |
How do MAO inhibitors work? | Prevent mono amine oxidase working to break down generalised NTs in synaptic clefts -> ^[NT] NTs include NA, Adrenaline, DA, 5HT, tyramine |
What are the 2 different forms of MAO inhibitors? | MAO a - inhibtis all monoamines, has dietary requirements - no tyramine containing foods (not used in dogs therefore) MAO b - inhibits all monoamines except 5HT, NO dietary requirements |
Give an example of a MAOb inhibitor. Is it licensed? | Selegeline licensed in Europe (disorders of emotional origin) and USA(cognitive dysfunction=alzheimers)- different purposes some evidence of neuroprotective effect |
What should Selegeline never be given in conjunction with? | SSRIs, TCAs or St Johns Wort- Serotonin syndrome can be fatal Remember long half life (20d!) |
Give 4 antipsychotics/neuroleptics (=tranquillisers/anti-scizophrenics) | ACP (acepromazine) Chlorpromazine Haloperidol (parrots feather plucking, lots of side effects) Risperidone |
How do antipsychotics work? | Block DA receptors (and newer compounds may also have 5HT antag) |
Are antipyschotics used regularly in animals? | No because of side effects | Although still used a bit in Europe |
What are the side effects of antipsychotics? | ^PRL (-> milk production) Seizures Sedatino and anticholinergic effects Extra-pyramidal symptoms eg. muscle tremor (due to blocking of DA receptors in basal nuclei, controlling motor function) - seen more in high potency neuroleptics eg. haloperidol |
Give some examples of low potency antipsychotics | Chlorpromazine, acepromazine | - low specificity, hence many side effects |
Give some examples of high potency antipsychotics | Haloperidol, azaperone (eg. Suicalm, give to pigs before mixing) more specific less sedation but greater risk of extra-pyramidal effects |
Give some examples of atypical neuroleptics/antipsychotics | Clozapine, ripseridone | - newer, potentially better, less side effects |
Is ACP recommended for tranquillising anxious animals? | NO - provides motor sedation but no anxiolytic effect |
Give some examples of anticonvulsants | RARELY USED (Antiepileptics) Phenobarbitone (Epiphen) Phenytoin (Epanutin) Primidone (Mysolene) Carbamazepine (Tegretol) |
When may carbamazepine be used? | Peripheral sensory neuropathy/ectopic firing eg. Burmese cats with facial pain where scratching -> neuralgia erratic absorption so best administered with food |
What types of partial seizures are possible? | Anywhere in the brain eg. visual (fly snapping) Motor/central brain (absent seizure) Amygdala/limbic system (sudden emotional response/jump up) |
Which drug is advocated for use with motor partial seizures? What must be wary of? | Phenobarbitone (used to be used more widely but effect due to sedation only) regular blood monitoring to check hepatotoxicity |
What is the action of Phenytoin? | Reduces spread of focal seizures | - used extensively in humans |
How does the pharmacokinetics of phenytoin differ in cats and dogs? | Dogs - metabolised very rapidly, high and frequent dosing needed Cats - metabolised slowly, problems with toxicity |
What is the effect of progestagens? | Anti-testosterone, secondary sedative effect - non-specific |
Are progestagens advocated? What are the side effects? | NO common and severe side effects - ^apetetie, weight gain - hyperglyceamia - diabetes - lethargy - poor cognitive function - mammry hyperplasia - adencarcinoma (mammary) - endometrial hyperplasia - pyometra - aspermatogensis - adrenocroticol supression - bone marrow suppression -retinal detachment |
Are progestagens licensed? | Yes unfortunately dogs also advocated for use in cats sometimes used to test for effect of castration beware secondary sedative effect which may mean castration doesnt have same impact testosterone driven tumours may shrink with progestagen use - if this proves true then castration will hope treat tumour |
Give 4 treatments of age related changes | selegeline A antag Xanthine derivative Dietary intervention |
Give a common drug combination | Benzodiazepenes and TCAs to manage acute episodes in dogs |
What does polypharmacy increase the risk of? | Side effects and problems with long term use |
What should be carried out throughout pharmacological treatment? | Blood monitoring (prior to starting medication swell to check for normal levels) |
Can off label drugs be used? | Yes providing informed consent is given |