Drugs for Pain - Martin Flashcards
opiod full agonst
morphine
fentanyl
opiod partial agonist
codeine
hydrocodone
oxycodone
mixed agonist/antagonist at opiod
buprenorphine
opiod antagonist
naloxone
loss of pain perception
analgesia
morphine tx
aware of pain sensation - but not unpleasant
opiod to pt with no pain
nausea and vomiting
pain
sensory - component due to activation of pain receptors
reactive - altered by level of anxiety and stress
narcotic
any substance producing stupor and analgesia
opiate
any derivative of opium poppy
opioids
compounds that bind opioid receptors
endogenous opioid agonists
endorphins
enkephalins
dynorphins
synthesis of endogenous opioid peptides
from POMC
opioid receptors
mu - euphoria
kappa - dysphoria
delta
opioid receptor mechanism
all GPCRs
inhibit cAMP
modulate K channels - K efflux and hyperpolarization
reduce Ca influx - inhibit NT release - glutamate, substance P
spinal cord opiod receptors
pain signaling
limbic system
addiction potential
-with opioid receptors
heroin OD death
resp depression
euphoria
with mu receptors
adverse of opioids
constipation
opioid effects
analgesia euphoria/dysphoria sedation resp depression cough suppression
coma and resp depression with miosis
pupil constriction
hint that pt is drug user - opioids
dilated pupil - other types of coma
if asphyxia develops with opioid overdose
get mydriasis - pupil dilation
severe brain injury
CI for opioid use
because they increase CSF pressure
constipation
with chronic therapy with opioids
opioids and asthmatics
no - because release histamine
can result in bronchoconstriction
morphine
binds all opioid receptor
-high affinity at mu
high abuse potential and analgesia
high addiction potential**
pharmacokinetics of morphine
high first pass effect
need to give 4x oral vs. IV dose
distributed to tissues - even fetus - not during pregnancy
fentanyl
start quickly and stop quickly
severe constant pain tx
morphine
sharp intermittent pain tx
NSAIDs
pain and anxiety with MI
tx - morphine - 1st line
relief of dyspnea from left ventricular failure and acute pulmonary edema
tx - morphine
- anxiolytic
- reduced perception of SOB
cough suppression
dextromorphan and codeine
diarrhea
loperamide
diphenoxylate
difenoxin
atropine added to dephenoxylate and difenoxin - to prevent addiction
fentanyl
100x more potent than morphine
used in anesthesia
rapid onset of action and short duration of action
epidural - analgesia post op and during labor
methadone
less euphoria and long duration of action
used for withdrawal of heroin or morphine users
oral
pt slowly weaned off methadone
-causes a withdrawal syndrome that is milder
meperidine
OB/GYN use
-dilates pupils
less effect on smooth muscle - so can use in obstetrics
short term use only - toxins accumulate
heroin
diacetylmorphine
- schedule I
- converted to morphine in body
partial agonists
codeine
hydrocodone
oxycodone
combined with NSAIDs - increase analgesia
outpatient analgesics
tylenol with codeine codeine/aspirin hydrocodone/acetaminophen oxycodone/acetaminophen oxycodone/aspirin
buphrenorphine
partial agonist at mu receptor
use - opioid detox
not as bad withdrawal as methadone
tx opioid OD
naloxone
naltrexone
opioid antagonists
antagonist to pt dependent on opioids
precipitates withdrawal syndromes
opiate reward pathways
GABA and dopamine pathways
opiate agonist - reduce excitability and transmitter release
inhibit in VTA on GABA interneurons
increase outflow from ventral pallidum - correlated with positive reinforcing state
opioid tolerance
to analgesia, resp depression, euphoria, and sedation
NOT to miosis and constipation
cross-tolerance
to all opioid agonists
withdrawal rom opioid sx
rhinorrhea, lacrimation, yawning, chills, piloerction, hyperventilation, hyperthermia, mydriasis, vomiting, diarrhea, anxiety
tx of opioid withdrawal
supportive care
clonidine - alpha2 agonist
-reduce craving, anxiety, and sympathetic outflow
opioid overdose
1 lethargy/coma
2 depression of respirations
3 pinpoint pupils
also - hypotension, hypothermia, pulmonary edema, convulsion, hypoxia - dilated pupils
tx opioid OD
opioid antagonist - naloxone
