pharmacology of opioids Flashcards
what are the chemical classes of opioids?
phenathrenes
phenylpiperidines
benzomorphans
dipheylheptanes
what are the functional classes or opioids
opioid agonists
mixed agonists/antagonists
opioid antagonist
give a classic example of opioid agonists (5)
morphine
methadone
fentanyl
codeine
hydrocodone
give an example of a mixed opioid agonist/antagonist (2)
pentazocine
buprenorphine
given an example of opioid antagonists (2)
naloxone and naltrexone
opioid drugs MOA
bind to the opioid receptors in the CNS and inhibit pain pathways giving a generalized CNS depression
onset of action of an opioid is dependent on what
patient
duration of pain relief in opioids
immediate release
extended release
epidural/intrathecal
suppository
immediate release: 3-5 hrs
extended release: 8-24 hrs.
epidural/intrathecal- up to 24 hrs
suppository - 3 to 7 hrs
when do we use opioid therapy
in acute/chronic pain and pain management
MI, sickle cell crisis, back pain, cancer, post operative procedures, adjunct to anesthesia, antitussive*
antidiarrheal
opined drug side effects
CNS depression
Respiratory depression-BBW
constipation
hypotension
what is the black box warning associated with using opioids?
respiratory depression (can be fatal) monitor closely especially during initiation or dose escalation.
*carbon dioxide retention from opioid induced respiratory depression can exacerbate the sedating effects of opioids
acute effects of opioids
sedation, euphoria, loss of cough reflex (antitussive), slowed CNS and heart
chronic effects of opioids
tolerance, hepatic and brain damage, dependance and addiction, loss of appetite, loss of libido
hepC from sharing needles
how do sedatives/hypnotics interact with opioid drugs
they increase the central nervous system depression (respiratory depression)
how to antipsychotics interact with opioids?
increase sedation and cardiovascular effects
how do monamine oxidase inhibitors interact with opioids?
they are contraindicated because they can cause hyper pyrexic coma
fentanyl is _ times more potent than morphine
100
lower doses of opioids before analgesic effects are
antidiarrheal
antitussive
euphoria
nausea
higher doses of opioids after analgesic effects are?
mitosis/vomiting
sedation
respiratory depression
coma/death
what is the function of the mu receptor
and what is its endogenous opioid peptide affinity
supraspinal and spinal analgesia
INHIBITION OF RESPIRATION
slowed GI transit
modulation of hormone and NT release
**ENDORPHINS
what is the function of the delta receptor
and what is the endogenous opioid peptide affinity
supra spinal/spinal analgesia
modulation of hormone and NT release
ENKEPHALINS
what is the function of the kappa receptor
and what is the endogenous opioid peptide affinity
supra spinal and spinal analgesia
PSYCHOMIMETIC EFFECTS
slower GI transit
DYNORPHINS
which drug is an agonist at the mu, delta, and kappa receptors
morphine!
which drug is an agonist at the mu receptor
methadone
what drug is a partial agonist at the mu, delta, and kappa receptor
buprenorphine
what drug is an antagonist at the mu and delta receptor
naloxone
_ is an opioid agonist that is indicated for the management of pain not reponsive to non-narcotic analgesics
do not use if there is sulfa allergy, bronchial asthma, or respiratory depression
morphine
what opioid is indicated management of persistent moderate to severe chronic pain that requires continuous around the clock opioid administration for an extended period of time
**pain is not controlled with non-narcotic anaglesics, combination opioids, all option exhausted
fentanyl
which opioid is most appropriate to manage abstinence symptoms and treat opioid use disorder in an outpatient rehabilitation setting (withdrawal acute and active)- full agonist
methadone
(clinics)
detoxification and maintence
which opioid is used for moderately to severe pain that is a semi synthetic narcotic with antitussive qualities (anti cough)
very common and highly prescribed
hydrocodone
hydrocodone is frequently combined with ?
acetaminophen
what opioid is a mixed agonist/antagonist that is used in the management of severe pain that alternative treatments have failed to treat
pentazocine
pentazocine is used when?
addiction?
used as a preoperative or preanaethesia medication and as a supplement
does not work for addiction
concomitant use of opioids with _ or another other CNS depressants including alcohol can result in sedation, depression, coma and death
benzodiazepines
prolonged used of _ during pregnancy can result in neonatal opioid withdrawal syndrome
pentazocine
which opioid is used in the management of severe pain that was not mitigated by other option and CANNOT be mixed with a mixed agonist/antagonist analgesics because it can precipitate withdrawal symptoms
meperidine
what opioid is an analgesic, antitussive and contains the least opioid analgesic activity
codeine
which opioid exposed patients and users to the risks of opioid addiction, abuse and tissues
codeine
uses of codeine
mild pain, cough, diarrhea
when discontinuing chronic opioid therapy the dose should be
gradually tapered down
which opioid is used to treat diarrhea and decrease the amount of drainage in patients with ostomies
patient with addiction can take this to minimize withdrawal effects (OTC)
loperamide
which opioid is indicated in the treatment of pain, addiction to opioids (withdrawal - acute and maintenance) it is a partial agonist and can be abused in similar ways to opioids
buprenorphine
what should you be monitoring in patients if you start them on buprenorphine
monitor for overdosing or underusing since it is a CYP3A4 inhibitor and inducers
MOA of naloxone
opioid antagonist at all sites
use of naloxone
opioid overdose (reversal of opioid reversal )
give even in opioid overdose is SUSPECTED
side effects of opioid antagonists
release of catecholamines that can cause acute withdrawal and cause pain
what is the MOA of naltrexone
opioid antagonist that is a competitive inhibitor at the mu receptors
(opioid addiction - maintenance)
use of naltrexone
alcohol disorder
opioid dependence
what is the concern surrounding naltrexone in opioid overdose
people treated with naltrexone may response to lower opioid doses than used before which can lead to intoxication (life threatening)
what is the concern surrounding naltrexone in opioid withdrawal
may precipitate symptoms of acute withdrawal in the opioid dependence in patients
acute withdrawal of opioids in neonates
naltrexone - shrill cry
can opioids exacerbate OTC pain relievers
yes
aspirin
ibuprofen
bismuth
naproxen
diphenhydramine
