opiods Flashcards
what are the 4 basic parts to the pathophys of pain
- transduction
- transmission
- modulation
- perception
what are the 3 receptor families that opiod receptors elicit effects on?
mu, kappa and delta
what does agonizing mu (u) receptors do?
Agonizing leads to analgesia, bradycardia, sedation, respiratory depression, euphoria, and physical dependence
what does agonizing kappa (k) receptors do?
Agonizing leads to analgesia and respiratory depression
what does agonizing delta (d) receptors do?
Agonizing leads to analgesia, respiratory depression, and sedation
Analgesia is produced when agents act as agonist on the three opioid receptors to inhibit the transmission of what?
nociceptive input and the perception of pain
what is the main MOA of opiods in regards to the mu opiod receptor?
Bind to mu opioid receptors in the
-CNS, GI TRACT and BLADDER causing inhibition of ascending pain pathway altering the perception of and response to pain
what are opiod receptors MOA in regards to kappa and delta receptors (less important that mu receptor MOA) ?
kappa- act in dorsal horn of spinal cord, inhibit substance P release
delta- inhibit release of excitatory neurotransmitters from nerve terminal
what is the benefit/downsides of transdermal patch preparation of opiod?
better longterm pain control but takes longer to work
benefit of using intranasal prep of opiod?
avoid 1st pass and dont need as high of a dose
what is the difference between a full and partial opiod agonist ?
full: no clinically relevant max response (no ceiling effect) - as dose is raised, analgesia effects increase until analgesia is achieved OR dose-limiting side effects occur
partial: produces less than a max response when fully-occupying receptors (ceiling effect)
what is a mixed agonist/antagonist?
Drug acts as a full agonist, but antagonist component binds to receptor without activating it to prevent increased binding of agonist. (ceiling effect)
what is a Naturally occurring opioid that is weak analgesic compared to morphine?
codeine
what is codeine used for?
use low for anti-tussive, then at higher doses for mild-moderate pain
codeine is contraindicated in children under age ____ or undergoing what procedures?
18
tonsillectomy/adenoidectomy
what do we need to worry about with the metabolism of codeine?
codeine is converted to morphine by CYP2D6…
rapid metabolizers: convert codeine to higher than usual levels of morphine causing toxicity
poor metabolizers: who when taking CYP2D6 inhibitors (ex. Fluoxetine) the cannot convert codeine to morphine and may not experience analgesic effect
what is a Semi-Synthetic opioid (means we tweaked a naturally occuring one and manufactured it) that is metabolized by CYP2D6 to hydromorphone?
hydrocodone (loratab)
what is the absorption and metabolism of morphine?
good abs, extensive 1st pass metabolism
what patient population do you need to be careful prescribing morphine for?
patients with renal insufficiency because of accumulation of toxic metabolite
(Patients have agitation, confusion, & delirium)
what are “abuse deterrent formulations” of morphine and oxycodone?
formulations that, when crushed/dissolved for injection either illicit NO EUPHORIC effects or illicit ADVERSE effects
what kind of drug is hydromorphone? strength compared to morphine?
semi-synthetic opiod, several times more potent than morphine (more lipophilic = faster abs)
what are the different formulations of hydromorphone?
IV, rectal, PO (short and long acting)
what would be a safer choice than morphine for someone with renal insufficiency?
hydromorphone
fentanyl is ___ times more powerful than morphine
100