Clinical Pharmacology of Sedatives Flashcards
what is a tranquilizer and examples
relieves anxiety without drowsiness
ex. phenothiazines, butyrophenones
what are neuroleptics and examples
tranquilizer used in treatment of psychoses
ex. penothiazines
what are sedatives and examples
calming effect with drowsiness
ex. alpha 2 adrenoreceptor agonists
what are hypnotics
induce sleep
ex. benzodiazepines, propofol
what is the mechanism of action of acepromazine
non-selective dopamine antagonism
what is the effect of acepromazine
- tranquilization/sedation
- anti-emesis
what other receptor types does acepromazine antagonize and what do these cause
- alpha 1 adrenergic receptors: vasodilation and hypotension
- muscarinic: decrease GIT motility
- histamine H1
what are the cardiovascular effects of acepromazine
- vasodilation leading to hypotension
- anti-arrhythmic action
why does acepromazine cause vasodilation and hypotension
alpha 1 adrenergic antagonist causes drop in BP initially
how does acepromazine cause ant-arrhythmic action
increases threshold for adrenaline/epinephrine induced arrhythmia
what are the respiratory effects of acepromazine
in bracycephalics sometimes causes an effect
sedation may worsen or improve the distress
what are the GI tract effects of acepromazine
- reduced smooth muscle activity
- anti-sialagogue action: reduced saliva
what are the other effects of acepromazine (4)
- hypothermia: peripheral vasodilation
- penile prolapse and/or priapism –> paramphimosis
- decrease in hematocrit
- mild anti-histamine activity
what are the routes of admin of acepromazine
IM (IV, SC)
oral pastes/tablets (20-55% oral bioavailability)
what is the duration of action of acepromazine
up to 4 hours or more
where is acepromazine metabolized
liver
what are potential drug interactions of acepromazine
potentiates effects of opioids, injectable and inhaled anethetics
what are the clinical indications of acepromazine (4)
- premedication prior to general anesthesia
- sedation
- motion sickness
- “calming” effects
what are the contra-indications of acepromazine
- hypovolemia
- breeding bulls and stallions
what are the cautions of acepromazine in some breeds (2)
- brachycephalic & giant breeds: increased sensitivity
- vasovagal syncope in boxers
what is vasovagal syncope in boxers caused by acepromazine
vasodilation leads to hypotension and then inappropriate bradycardia causing the dog to faint
how is vasovagal syncope treated in boxers after acepromazine administration
anti-muscarinic drugs –> atropine +/- fluids
how do you prevent the vasovagal syncope in boxers after acepromazine
use lower doses
or combine with anti-muscarinic
what is the mechanism of action of butyrophenones
dopamine antagonism
what are the effects of butyrophenones
- sedation/tranquilization
- anti-emesis
what are the side effects of butyrophenones
- vasodilation & hypotension (a1 adrenergic antagonism)
- hallucinations
- agitation
what are examples of butyrophenones
- azaperone (Stresnil)
- fluanisone + fentanyl (Hypnorm)
what is azaperone used for
sedation, premedication or behavioural modificaiton in pigs
how is azaperone administered
deep IM
what are the side effects of azaperone
- hypotension (mild)
- hypothermia
- priapism
what is hypnorm used for
sedation and premedication in mice, rats, rabbits, guinea pigs
how is hypnorm administered
IM or IP
what can hypnorm antagonize
fentanyl (ex. butorphanol)
what are examples of benzodiazepines
- diazepam (Valium)
- midazolam (Hypnovel)
what is the mechanism of action of benzodiazepines
potentiate activity of inhibitory neurotransmitter GABA
what are the effects of benzodiazepines
- anxiolytic action
- muscle relaxation
- anticonvulsant properties