opioid agonist-antagonist Flashcards
name the 5 agonists/antagonists we need to know
- Pentazocine (Talwin)
- Butorphanol (stadol)
- Nalbuphine (Nubain)
- Buprenorphine (Buprenex)
- Buprenorphine/Naloxone (Suboxone)
reversibly binds
receptor at same site as agonist but does NOT
activate receptor.
competitive antagonist
what are the effects from competitive antagonists from?
preventing agonists from binding
to and activating the receptor
what does the clinical response of competitive antagonists depend on?
the concentration of agonists in the system that the drug has to compete with to bind to receptor site
irreversibly binds
receptor at a separate site from agonists.
Non-competitive antagonists
think non-comp = drug does not care about winning receptor
2 important things that Non-competitive antagonists do
– Inhibits the full agonist response
Prevents conformational changes in receptor which
are required for receptor activation.
Drug has a high affinity for the receptor but not
so much intrinsic activity
Partial agonist
this type of drug binds to a receptor but causes a decrease in receptors response
• Partial agonist
greater effects at the receptor than the defining receptor agonist (morphine)
Superagonist
*fent vs morphine
Opioid Agonists/Antagonists have most Successful use in these type of patients
opioid addiction/chronic use population
Opioid Agonists/Antagonists have what effect on morphine and pure agonists?
Produce a degree of competitive antagonism
to morphine and pure agonists
What type of pain are opioid agonist/antagonists appropriate for?
acute & chronic pain
even tho agonist/antagonists are Synthetic or semi-synthetic analgesics, what drug are they structurally r/t?
morphine
what characteristics to ag/ant have on mu receptor (broad)
Partial µ agonist producing limited to no effects (less resp depression)
what two receptors do ag/ant effect most?
kappa and delta!
what is the cool thing about ag/ant?
Reverses opioid overdose while continuing to
provide analgesia
are Opioids that have antagonist effects on µ and к
receptors useful in pain management?
Yes
6 Benefits of Opioid Agonists/Antagonists
- great when pt cant tolerate full agonist
- analgesia (k) without resp depression (mu)
- used in pt with opioid dependency hx
- ceiling effects limit toxicity of drug
- no significant elevation of interbiliary pressure
- less constipation
because ag/ant do not cause significant elevation of interbiliary pressure, what pts are these good for?
Useful in patients with biliary colic
kappa receptors main side effect
Psych
dysphoria
will giving morphine after giving an ag/ant work well for analgesia?
Subsequent doses of agonist after opioid A/A may NOT provide
adequate analgesia
3 undesirable effects from kappa receptor
- dysphoria, confusion (elderly)
- no euphoria
- depression
these ag/ant are typically not appropriate for what patient population?
cards because of catecholamine release so increase in BP, CO
in regards to ceiling effect of response with ag/ant:
Depression of ventilation (advantage)
– Weak ability to decrease anesthetic requirement, really not great for “balanced” anesthesia plan
what receptor antagonist can lead to withdrawal
mu
CNS effects of kappa receptor
depression sedation dysphoria hallucinations delirium