Sedative And Anesthetics Flashcards
______________induces a state of behavioral change where anxiety is relieved and the patient is relaxed, but aware of their surroundings
Tranquilizer (neuroleptic)
____________ induces a state characterized by CNS depression and drowsiness, decreased awareness of surroundings
Sedative
__________ induces sleep
Hypnotic
_____________ attenuated nocicpetive input leading to reduced rain
Analgesic
______________ decreases central sensitization to pain
Antihyperalgesics
do not block transmission of stimulus
_______________ diminishes ability to perceive pain
Antinocipcetion
____________ induces analgesia and stupor bordering on anesthesia
Narcotic
________________ causes analgesia and amnesiac state produced by admin of a neuroleptic and narcotic
Neuroleptanalgesia
________________ are drugs given before a medical, surgical, or invasive produced to induce sedation, analgesic, ad relieve anxiety
Premedication
What makes up the blood brain barrier?
Tight capillary endothelial junctions
Glial cells
Active transport for removal of organic acids or bases
CSF into venous drainage
What re the excitatory neurotransmitters?
Glutamate (NMDA receptor) ACh Epi/ Norepi Dopamine Serotonin Histamine
What are the inhibitory neurotransmitters?
GABA
Glycine (spinal cord)
Neuroleptics (tranquilizer) can be classified into
Phenothiazine derivative
Benzodiazepine derivative
Butyrophenone derivative
A2 agonists
What are the main effects of neuroleptics
Sedation and hypnosis
Emotional quietness
Dissociation from surroundings
What are the only group of neuroleptics to have analgesic effects?
A2 agonists
T/F: none of the neuroleptics have true anesthetic effects
T
What is the most common phenothiazine?
Acepromazine
What is the MOA of phenothiazines?
Competitively antagonize excitatory dopamine receptors in the CNS
Inhibit vomiting
Prolactin release
Muscle relaxation
How are phenothiazines administered?
IV, IM,SQ, PO
What is the oral bioavailability of phenothiazines in dogs?
Low
About 20%
Where are phenothiazines metabolized
Liver, excreted in urine
What effects do phenothiazines have in the CNS?
Sedation (dopamine receptor)
Decreased spontaneous motor activity
Hypothermia and hyperprolactinemia (hypothalamus)
Anti-emetic (alpha 2 receptor)
What are the effects of phenothiazines on the CVS?
Block alpha 1 receptor
Vasodilation-> hypotension ‘epinephrine reversal’
What breeds are more susceptible to the CVS effects of phenothiazines
Boxers/brachydephalics
Large breed dogs and sighthounds
What effects do phenothiazines have on the respiratory system
Minimal at therapeutic dose
Depression at hight dose or with other opioids
What effects do phenothiazines have on skeletal muscle
Moderate relaxation
What are the precautions to using phenothiazines?
Boxers/brachycephalic/large dog/sighthounds.MDR1 mutations
When vasodilation is contraindicated
Stallions: penile prolapse
Cattle: not approved ->ruminal regurgitation
Aggressive dog: increase aggression
Excited animals : reduced sedative effect
Toxins: extrapyramial effect
Liver disease: hepatotoxic
Concurrent epinephrine use
What two phenothiazines are used as anti-emetics
Prochlorperazine and chlorpromazine
What phenothiazine is used as a antihistamine
Trimeprazine
What are the benzodiazepines
Agonists:
Diazepam
Midazolam
Alprazolam
Antagonist:
Flumazenil
Partial agonist:
Imepitoin
What is the MOA of benzodiazepines?
Bind and active benzodiazepine binding site on GABA receptor to cause hyperpolarization of neurons
(GABA is main inhibitory NT in CNS)
What is the distribution of benzodiazepine
Lipid soluble
Wide distribution
Cross BBB
Protein bound
What benzodiazepine is given IV
Diazepam
What benzodiazepine is given IM
Midazolam
What benzodiazepine is given orally
Alprazolam (diazepam has short duration and can cause hepatic necrosis in cats)
What are the clinical uses for benzodiazepines?
Anxiolytics (behavioral modifiers)
Anticonvulsant
Premedication (combine with other agents)
Sedation (not reliable on its own!) -> most reliable in ruminants
Muscle relaxation -> central effect but short lived
Appetite stimulation
What is used for specific reversal of benzodiazepines?
Flumazenil
Competing antagonist on GABA receptor
What are contraindications to using benzodiazepine
CAT: hepatotoxicity with oral diazepam
What are precautions to use in benzodiazepine ?
Horse: muscle fasciculations seen (ataxia at high dose)
Paradoxical excitement (fear/aggressive animals)
Propylene glycol (diazepam injection-> pain IM and hypotension IV
Pregnancy -teratogenic
Hepatic and renal disease - altered metabolism and excretion
T/F: acepromazine has tranquilizer going and analgesic effects
F
What is the most important cardiovascular side effect of acepromazine ?
Hypotension
Why is oral diazepam contraindicated in cats
Hepatotoxicity
What are the A2 agonist neuroleptics
Dexmedatomidine
Medetomidine
Xylazine
Yohimbine
Where is the pain pathway will A2 agonist have and effect
Perception
Modulation
Transmission
Dexmedetomidine is used in what species
Dogs
Cat
Exotic
Xylazine is used in what species
Horse, deer, elk
What is the reversal agent for dexmedetomidine
Atipamezole
What is the reversal agent to xylazine
Yohimbine
What is the MOA of Xylazine and dexmedetomidine ?
Competitive a2 agonism
- > Brian (sedation)
- > dorsal horn (analgesic and muscle relaxation)
Competitive agonism of a1 receptors
-> vasoconstriction
Activation of a2 receptors stimulates what pathway of action
G(inhibitory) protein receptor pathway
- > negative coupling to reduce adenylyl cyclase and decrease cAMP
- > increase outward flow of K+
Hyperpolarization
Inhibit neurons
Decrease NE release