apex opioids Flashcards
tolerance
associated with opioids. due to receptor desensitization and increased synthesis of cAMP.
tolerance does not develop
to mitosis or constipation
early signs of withdrawal
diaphoresis insomnia restlessness
late signs of withdrawal
abdominal cramping n/v
most potent opioid
sufentanil
least potent opioid
meperidine
which opioids have active metabolites
morphine and meperidein
remifentanil and dosing
lean body weight for dosin
methadone receptor
mu
meperidine receptor
mu and kappa
mu endogenous ligand
endorphin
delta endogenous ligand
enkephalin
kappa endogenous ligand
dynorphin
mu-3
immune suspression
morphine metabolism
morphine 6 glucuronide
very potent if it builds up it will create respiratory depression and toxicity after morphine
patients on dialysis are unable to excrete m6g and are more likely to experience respiratory depression and toxicity after morphine
meperidine metabolism
metabolite is normeperidine
half as potent
it reduces the seizure threshold and increases ins excitability. caution in elderly and dialysis.
remifentanil metabolism
hydrolyzed in the plasma by erythrocyte and tissue esterase’s. (not pseudocholinesterase)
what is meperidine structurally related to ?
atropine and exhibits anticholinergic effects such as tachycardia, mydriasis and dry mouth
which opioid does not get metabolized by the liver?
remifentanil
which opioid can produce skeletal muscle rigidity
fentanyls
what is the treatment for skeletal muscle rigidity
paralysis and intuabtion
common characteristics of partial agonists
produce analgesia with a reduced risk of respiratory depression
have a ceiling effect beyond which additional analgesia is not possible
reduce the efficacy of previously administered opoids
can cause acute opioid withdrawal in the opioid dependent patient
can cause dysphoria reactions
carry a low risk of dependence
are used in patients who cannot tolerate a full opioid agonist
naloxone (which receptors) which has the greatest affinity
mu has the greatest affinity
kappa
delta receptors.
naloxone indications
acute reversal of opioid induced respiratory depression
reversal of respiratory depression in the neonate whose mother received an opioid
treatment of opioid overdose
does naloxone cross the placenta
yes it does if giving it to an opioid abusing mother it can precipitate acute opioid with drawl in the neonate
naloxone please remember
last 45 minutes- it may be shorter than the opioid you are reversing- remember to tell PACU you gave it. may need an infusion.
naloxone side effects
pul edema tachycardia, cardiac death
nalmefene who do we give it to?
can be used to maintain recovering opioid abusers.
the experience of pain are divided into 4 steps. please name them
transduction
transmission
modulation
perception
transduction
peripheral nerves are activated to organize the inflammation response so the brain can interpret
a delta fibers- fast sharp
c fibers- slow dull
transmission
3 neuron pain pathway along the spinothalamic track
1-periphery-drg
2-drg-thalamus
3thalamus-cortex
modulation
modulation is at substantial gelatinous in the dorsal horn
the descending inhibitory pain pathway begins in the periaqueductal gray and the rostroventral medulla it projects to the substantial gelatinous.
pain is inhibited when spinal neurons release gaba and glycine
the descending pain pathway releases NE, 5HT, and endorphins .
pain is augmented by central sensation and wind up
perception
how we feel about pain
allodynia
reduced threshold to pain stimulus
hyperalgesia
increased response to pain stimulus.
gender plays a role in pk/pd differences
how is morphine different for women
greater analgesic potency
slower onset of action
longer duration of action
lower post operative opioid consumption
name the opioids most potent to least potent
sufentanil-fentanyl-remifentanil-alfentanil-hydromorphone-morphine-meperidine
meperidine is structurally related to?
atropine
meperidine is structurally related to atropine meaning it will exhibit what effects
tachycardia, mydriasis, and dry mouth
name drugs that cause histamine release
meperidine, morphine, codeine, and oxycodone
how quickly does alfentanil equilibrate?
1.4minutes
due to it being 90% unionized- readily crosses the BBB
how quickly does fentanyl and sufentanil cross the blood brain barrier
6ish minutes
methylnaltrexone
unable to cross the BBB
it does not reverse respiratory depression
helpful in reversing opioid induced bowl dysfunction
nalmefene
used to maintain recovering opioid abusers last 10 hours
naltrexone
last 24 hours- DOES NOT UNDERGO SIGNIFICANT FIRST PASS METABOLISM. used to maintain opioid abusers
