Sedatives Flashcards
what classes are in sedative hypnotics?
phenothiazine derivatives
butyrophenone derivatives
benzodiazepine derivatives
alpha-2-adrenergic receptor agonists
what is the most common phenothiazine derivative?
acepromazine
what do phenothiazine derivatives do?
neuroleptics
major tranquilizer
antiemetic
what is the mechanism of action for phenothiazine derivatives?
D2 antagonist
sedate by inhibiting postsynaptic central dopaminergic receptors
D2 receptors are GPCRs
D2 receptors in chemoreceptor trigger zone produce antiemetic effects
peripherally block norepinephrine from binding alpha1 adrenergic receptors: peripheral vasodilation
what are the indications of phenothiazine derivatives?
routine sedation
preanesthetic period
often combined with opioids to produce synergic effects of each class (better sedation and analgesia)
what are some butyrophenone derivatives?
haloperidol
doperidol
what are butyrophenone derivatives?
antipsychotics
what is the mechanism of action for butyrophenone derivatives?
D2 antagonist
D1, 5HT, alpha1, and histamine antagonist
what are the indications for butyrophenone derivatives?
azaperone for swine for calming effects (mixing weanlings and feeder pigs)
transportation
obstetrical conditions
anesthetic adjunct for wildlife
what are the benzodiazepine derivatives?
diazepam (valium)
midazolam
lorazepam
zolazepam
what is the mechanism of action for benzodiazepine derivatives?
increase frequency of the opening of the chloride ion channel
majority GABAa receptors in cerebral cortex, very few outside of CNS
synergistic effect with barbituates
what are the indications for benzodiazepines?
anticovulsants
adjuncts to anesthetic induction agents
skeletal muscle relaxants
behavioral modification (anxiolysis and sedation)
what are the CNS effects of benzodiazepines?
often sedation
when administered alone: different effects can occur (excitement, agitation, vocalization, dysphoria)
reduction in cerebral blood flow and oxygen consumption
what are some side effects of benzodiazepines?
minimal cardiovascular effects
may decrease respiratory rate bur rarely affect ventilation and oxygenation at clinical doses (dose dependent respiratory depression)
relaxation, ataxia, recumbency in musculoskeletal
no analgesia
do benzodiazepines have analgesia effect?
no
when can benzodiazepines cause respiratory depression?
higher doses
exacerbated by other CNS depressants or in debilitated patients
where do many of the side effects of diazepam hydrochloride (valium) arise from?
vehicle: propylene glycol
what side effects can propylene glycol have?
hemolysis (especially in cats)
pain on infusion
what can repeated PO administration of diazepam hydrochloride lead to in cats?
hepatic necrosis