Sedatives and Analgesics Flashcards
catecholamine receptor types
- domapine (D1, D2)
- adrenergic (a1, a2, B1, B2)
are dopamine receptors ionotropic or metabotropic
metabotropic
D1: Gs –> increase cAMP
D2: Gi –> decrease cAMP
D1 agonists
vasodilation of splanchnic organs
increased blood flow
D1 antagonists
vasoconstriction of splanchnic organs
decreased blood flow
D2 agonists
emesis
anxiety and fear
D2 antagonists
antiemetic
reduce anxiety and fear
a1 agonists
excitement
vasoconstriction
splenic contraction –> elevated HCT
hypertension
a1 antagonists
sedation
vasodilation
splenic relaxation –> low HCT
hypotension
a2 agonists
sedation
analgesia
muscle relaxation
high dose: vasoconstriction + hypertension
low dose: vasodilation + hypotension
bradycardia
increase urination (inhibit ADH)
hyperglycemia (decrease insulin)
a2 antagonists
excitement
muscle tone
tachycardia
decrease urination
hypoglycemia
acepromazine
D2 and a1 antagonist
central and peripheral effects
effects of acepromazine
D2 antagonist:
1. tranquilization
2. antiemetic
a1 antagonist:
1. sedation
2. vasodilation
3. hypotension
4. decreased PCV
dexmedetomidine
a2 agonist
central and peripheral effects
effects of dexmedetomidine
- sedation
- analgesia
- relaxation
- vasoconstriction + hypertension followed by vasodilation and hypotension
- bradycardia
- hyperglycemia
- polyuria
are opioid receptors ionotropic or metabotropic
metabotropic
Gi protein –> decreases cAMP
opioid receptor subtypes
mu
kappa
mu > kappa efficacy
opioid receptor agonists
overall decreased neuronal excitability
- analgesia
- species dependent CNS effects
- hypoventilation
- decreased peristalsis (constipation)
species dependent CNS effects of opioid agonists
sedation: dogs, primates, rodents
euphoria: cats (low dose)
excitement: cats, horses (high dose)
morphine
mu and kapp opioid receptor agonist
central and peripheral effects
effects of morphine
- analgesia
- sedation
- hypoventilation
- decreased GI motility
GABAa receptor structure
2 a subunits
2 b subunits
+/- y subunit (benzodiazepines)
ionotropic:
forms a central Cl pore
GABAa function
inhibitory receptor
hyper polarizes the cell to decrease cell excitability
benzodiazepine sensitive GABA receptors
contains a, B, and y subunits
benzodiazepine binds to a DIFFERENT site than GABA
anesthetic sensitive GABA receptors
contains a and B subunits
anesthetics bind to SAME site as GABA
may have y subunit for benzodiazepine to bind
GABAa agonists
inhibits RAS to inhibit arousal
- species dependent effects
- amnesia
- anticonvulsant
- muscle relaxation
- anesthesia
- decreased respiratory drive, ventilation, and altered breathing pattern
species dependent GABAa agonist effects
sedation: sheep, goats, cattle, pigs, primates
excitement: dogs, cats, horses
midazolam
benzodiazepine (GABA agonist)
central and peripheral effects
effects of midazolam
- sedation/excitation (spp.)
- amnesia
- anticonvulsant
- muscle relaxation
propofol
anesthetic GABA agonist
central and peripheral effects
effects of propofol
- sedation (low dose)
- anesthesia (high dose)
- amnesia
- anticonvulsant
- muscle relaxation
- hypoventilation
NMDA receptors
ionotropic:
forms a central cation pore
inhibited by Mg blocking pore
function of NMDA receptors
excitatory receptor
depolarizes the cell to increase cell excitability
important in hippocampus for long term memory
NMDA antagonists
- amnesia
- hallucinations
- dissociative anesthesia
- increased muscle tone/rigidity
- decreased spontaneous movement
- analgesia
ketamine
dissociative anesthetic
central and peripheral effects
effects of ketamine
- amnesia
- increased muscle tone/rigidity
- decreased spontaneous movement
- hallucinations
- dissociative anesthesia
- analgesia