Narcs Flashcards
(20 cards)
Pharmacological response of µ and δ receptor subtypes
µ: analgesia + respiratory depression
δ: analgesia
Analgesic actions of opoids (ascending vs descending control)
Opioids BLOCK ascending pathway
Opioids ACTIVATE descending pathway
What do opioids relieve better, dull, constant pain, or sharp intermittent pain?
dull, constant pain
Do opioids reduce neurogenic pain, nociceptive pain, or both?
Just nociceptiive
If pt is having respiratory depression due to opiods, what do you give them?
Naloxone! (Narcan)
How does CO2 affect ICP? And why are opioids important?
Opioids decrease sensitivity to CO2 → CO2 levels rise → vasodilation → Increase ICP
(Basically, opioids cause vasodilation and increase ICP)
How do opioids have therapeutic effects in cardiovascular therapy?
Myocardial infarction: Fentanyl and morphine good
- analgesia
- alleviates apprehension
- decreases cardiac load
SHould you use opiods if pts has resp dysfxn? When can you?
No! But if there is pulmonary edema assoc. w/ cardiac dysfxn, then yea.
DDI for opioids
- CNS depressants (barbits)
- synergistic dep. - Antipsychotics (Phenothiazines)
- resp dep - TCADS, MAO inhibitors
- resp dep
Most commonly used opioid analgesic? Why should you be careful?
Codeine:
10% of pts metabolize it to morphine
(can give to babes)
Tramadol
mu agonist
also blocks monoamine uptake (ie: 5HT - potentiates descending pathway)
Fentanyl
100x more potent than morphine
- break thru pain
TRANSDERMAL, IV, lozenges, requires mech venti.
How do µ opoid receptors work in PAG?
In PAG, they block GABA release and remove tonic inhibition resulting in activation of PAG outflow
How do µ opoid receptors work in the spinal cord?
they are activated by enkephalins
-Presynaptically: decrease release of excitatory transmitters Glu + Sub P
- Post-synaptically (on 2nd order n): hyperpolarizes the neuron.
Both of these MODULATE transmission whose end result is decreased transmission of noci stim
Ketamine
NMDA receptor antagonist:
blocks glutamate receptor depolarization at 2nd order neuron in the ASCENDING PAIN PATHWAY
(decrease TRANSMISSION of noci stim)
Clonidine
a-2 agonist at dorsal horn in locus ceruleus - mod pain
Decrease in central sensitization to controle pain can be achieved by blocking what 2 things?
- Block VSCC: anticonvulsants (a2d ligand)
2. Block NMDA-GLu receptors: ketamine
Decrease in peripheral sensitization to control pain can be achieved by blocking what ?
VSSC: anticonvulsants, local anesthetics
Anticonvulsants MOA
Na+ channel block
Ca2+ channel block (a2d subunit)
Tricyclic antidepressants MOA
inhibit reuptake of NE/5HT
