pharm 5 Flashcards
steps of experiencing pain
transduction, transmission, modulation, perception
what is transduction
chemicals activate peripheral nerves, cause immune cells to release proinflam compounds
turn into an AP
what nerve fibers transmit pain
a dela- fast pain (sharp and well localized)
c fibers- slow pain (dull and poor localized)
what is pain moulation
modulated as it goes towards cerebral cortex
most important sitte: substantia gelatinosa in dorsal horn
perception
processing of afferent signals in cerebral cortex and limbic system
MOA of opioids
reduces adenylate cyclase and camp
mu1, mu2, m3
mu1- analgesia, bradycardia, euphoria, low abuse, hypothermia
mu2- analgesia, bradycardia, constipation, dependence, resp depression
mu3- immune suppression
kappa receptor
antishivering, diuresis, dysphonia, delerium, hallucination
do opioids affect bp and contractility
minimally; hypotension seen with moprhine and meperidine are likely from histamine release
contracility is not affected
when there is decreased vent respose which way oes co2 curve shift
right
gi effects from opioids
biliary pressure: contraction of sphincter of oddi- increases biliary pressure
reversed by narcan of glucagon
gastric emptying prolonged
peristalsis slowed
gu effects from opioids
mu and delta
urinary sphincter contraction (relaxation causes voiding)
detrusor relaxation (contraction causes voiding)
what opioids have histamine release
morphine, meperidine, codeine
what are the immunologic effects of opioids
inhibition of cellular and humoral immune function
suppression of natural killer cell function
how do opioids affect thermoregulation
opioids reset hypothalmic temp set point
decrease core body temp
IV opioids most to least potent
sufentanil > fentanyl = remi > alfentanil > hydromorphone > morphine > meperidine
what opioids have an active metabolite
morphine and meperidine
how are opioids metabolized
except for remi- all of the opioids undergo hepatic biotransformation
morphines active metabolite
morphine-> m6p -> resp depression
active metabolite of meperidine
normeperidine-> seizures
what opioid has the fastest onset of action
alfentanil (b/c of its pka 6.5)
what opioid has the largest vs smallest vd
largest- fentnayl
smallest- femi
how do you calculate remi infusion (what weight)
LBW - b/c it does not distribute through body fat- metabolized too fast
remi contains a __ linkage
ester
