Term
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Definition
opioid = any natural or synthetic chemical with morphine-like actions
opiate = natural product from the opium poppy |
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Term
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Definition
receptors in the body that have as their endogenous ligands (dynorphins, endorphins, enkepalins) opioid-like peptides
endogenous peptide and opioid drugs act as same site
4 main classes |
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Term
| main classes of opioid receptor |
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Definition
*mu, *kappa, delta, sigma
*mu and kappa (not as much so) play the biggest role in pain relief |
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Term
| responses from mu, kappa activation |
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Definition
analgesia
sedation
decreased gut motility
ventilatory depression+
euphoria+
physical dependence+
+mu only |
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Term
| abusive/dependent properties opioids |
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Definition
ventilatory depression, euphoria, physical dependence
only from mu receptor activation, NOT kappa |
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Term
| classifications of opioid agonists and antagonists |
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Definition
"pure" opioid agonists
opiod agonist-antagonists
"pure" opioid antagonists |
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Term
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Definition
"does nothing but..."
drugs doesn't do anything other than directly act on the opioid receptors |
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Term
| where do opioids work to cause their effects? |
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Definition
analgesia: act mainly on brain (and brainstem, spinal cord, primary afferent peripheral terminals)
medullary respiratory control center
chemoreceptor trigger zone (nausea, vomiting)
GI tract |
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Term
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Definition
prototype is MORPHINE
activated both mu and kappa opioid receptors |
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Term
| morphine pharmacokinetics |
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Definition
extensive first-pass metabolism = don't use orally to initiate analgesia
oral OK to maintain treatment once liver enzymes have been saturated so more can escape liver to reach systemic circulation |
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Term
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Definition
"gold standard" tx for severe pain
relieves anxiety and sedates - suppression in the perception of pain as an unpleasant stimulus (good in MT pts)
venodilation to decrease pulmonary vascular congestion (MI, pulm edema)
sometimes as general anesthetic |
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Term
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Definition
euphoria
ventilatory depression
increased ICP
nausea, emesis
urinary retention or urgency
gall bladder pain/bile duct spasm
hypotension |
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Term
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Definition
dose-dependent medullary depression leads to a decrease in ventilatory rate and depth causing decreased pO2, increased pCO2, and increased ICP
opioids inhibit brain's protective response - it is unable to sense this decrease in pH
*ventilatory depression is #1 cause of death* |
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Term
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Definition
CHI can decrease ventilation and increase ICP (same as opioids)
opioid drugs for pain can exacerbate these effects and cause other SE that may interfere with a MSE
morphine can alter the physiology and pathophysiology
avoid these drugs unless/until ventilation/ICP can be controlled |
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Term
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Definition
BIOLOGIC process that causes decreased drug effectiveness over time
increased drug dose required to restore level of effect |
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Term
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Definition
BIOLOGIC changes in various homeostatic "Set-points"
further changes (withdrawal) occur when drug administration is stopped |
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Term
morphine tolerance
(and most other pure opioid analgesics) |
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Definition
YES tolerance: to analgesia, vent depression, euphoria, some others
*NO tolerance: to miosis...always have pin-point pupils unless severe vent failure/death ensues (then dilate) |
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Term
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Definition
ratio of lethal and effective dose of a drug
TI = LD50 / ED50 |
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Term
| tolerance, therapeutic index (TI), and morphine |
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Definition
*TI of morphine does NOT chance much with development of tolerance to the drug
with tolerance, ED and LD both rise in parallel (tolerance persons can survive otherwise lethal opioid doses)
(in contrast to alcohol -- ED rises significantly more than LD) |
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Term
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Definition
| a patient who develops tolerance to one opioid agonist automatically is tolerant to all others |
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Term
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Definition
| suitable doses of any opioid that is only a strong agonist (e.g. morphine) can substitute for any other that has caused dependence, thereby preventing withdrawal syndrome for as long as drug administration lasts |
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Term
pain treatment in the opioid-tolerant patient
(e.g. heroin addict) |
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Definition
very high opioid doses may be needed to provide adequate analgesia
these would cause serious or fatal ventilatory depression in a "naive" patient |
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Term
| pain treatment in the respiratory-compromised patient |
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Definition
| the does of opioid that works for a patient with perfect pulmonary function may be too much for a patient with COPD/sleep apnea, etc... |
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Term
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Definition
intense/painful...but rarely fatal
inverse relationship between half-life and withdrawal s/sx
morphine/heroin: short acting drugs; brief but intense withdrawal s/sx
methadone: long acting drug; longer-lasting but milder withdrawal |
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Term
strong opioid agonists
examples |
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Definition
fentanly
sufentanyl
methadone
meperidine
hydropmorphone
oxymorphone |
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Term
| "-tanyl" morphine-like agonists |
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Definition
fentanyl, sufentanyl
same actions, desired and unwanted effects as morphine
about 50-75 times as potent as morphine
different actions indicated based on method of administration: parenteral, transdermal, transmucosal |
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Term
-tanyl
parenteral administration |
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Definition
general anesthesia induction, maintenance
combines with BDZs for "conscious sedation" in certain procedures where anterograde amnesia is desired (e.g. colonoscopy...of which Shlafer has had two in the past 12 months) |
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Term
-tanyl
transdermal administration |
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Definition
maintenance of severe, chronic pain (long-term control)
NOT for initiation of analgesia or fast management of pain spikes |
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Term
-tanyl
transmucosal administration |
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Definition
lozenges for pre-anesthetic medication or conscious sedation
lollipops for intermittent management of pain spikes in cancer patients |
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Term
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Definition
strong opioid agonist
PRO: great oral bioavailability, little 1st pass metabolism
CON: rate of elimination gets longer with repeat administration |
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Term
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Definition
long-term pain control
detox or maintenance therapy for morphine/heroin addiction (longer t1/2=longer but more tolerable withdrawal) |
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Term
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Definition
strong opioid agonist
PRO: less biliary tract spasm than morphine; shorter half life so less AEs (vent dep) is they occur
CON: short half life means more frequent dosing; toxic metabolite that can cause seizures; DDI with MAOIs/SSRIs/TCAs deadling to delirium, seizures, possible death |
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Term
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Definition
strong opioid agonists
morphine-like oral, parenteral, analgesics
5-10 times as potent and morphine
*substitution for morphine on a mg-for-mg bases can be lethal |
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Term
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Definition
very lipophilic - gets into brain fast
active metabolite ~ morphine in the CNS (accounts for the main effects that lead to its abuse) |
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Term
| top drugs for pain relief in US |
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Definition
all are "moderate" opioids
1: hydrocpdon/APAP
32: oxycodone/APA
34: codeine/APAP
combination analgesic products
APAP = tylenol/acetaminophen |
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Term
"moderate" opioids
codeine, hydrocodone, oxycodone |
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Definition
oral
suitable for moderate pain - severe pain would require doses too high based of their SE/toxicity
aspirin/acetaminophen potentiate the analgesic effects (combo have much lower potential for abuse)
good antitussive activity |
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Term
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Definition
oxycodone controlled-release tablets
designed to be swallowed whole and have gradual release/GI absorption
abused by crushing and ingesting/injecting/snorting to cause rapid absorption and intense opioid-like euphoria |
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Term
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Definition
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Term
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Definition
good kappa opioid receptor agonist: analgesia, respiratory depression (but not as severe as morphine)
weak agonist at mu opioid receptors, simultaneously blocks binding of stronger mu agonists
toxicity limits use for severe pain |
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Term
| morphine and mixed opioid agonist/antagonist |
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Definition
mixed agonist/antagonist (e.g. pentazocine) should NOT be used with patients already on a "pure" agonist because it will provid eonly modest analgesia, block effects of the "pure", and induce withdrawal and worsening of pain
OK as sole drug for moderate pain |
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Term
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Definition
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Term
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Definition
sole action is competitive bloackage of ALL opioid receptors (mu and kappa)
NO agonist activity
no effect on any other class of CNS depressants or the receptors they act on...means you will only see an effect in someone who is taking an opioid agonist |
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Term
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Definition
| main use: diagnosis and treatment of opioid overdose |
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Term
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Definition
injection, NO oral bioavailability
fast-acting, short duration compared to the opioids they are blocking = need repeat dosing when treating opioid OD |
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Term
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Definition
no intrinsic toxicity
if opioid originally given for pain, analgesia may be reversed
if given to opioid-dependent person, may quickly induce withdrawal syndrome |
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