Opioid Use Disorder Flashcards
which opioid receptor is mainly responsible for the opioid analgesic effect?
mu
T or F
kappa opioid receptors contribute to physical dependence
false
T or F
OUD can be cured?
false
can be treated and managed but not cured
what is the leading cause of death OUD?
overdose and trauma
what are the three stages of addiction?
- binge/intoxication
- withdrawal/negative affect
- preoccupation/anticipation
what happens when an opioid attaches to the mu opioid receptor?
triggers a structure in the brain called the mesolimbic (midbrain) reward system in the ventral tegmental area (VTA)
VTA system is responsible for release of DA in the nucleus accumbens (NAc) in the basal ganglia
release of DA in the NAc = pleasure
in the locus coeruleus: suppress release of NE –> drowsiness, slowed respiration, low BP –> opioid intoxication
what happens in the brain when opioids are taken repeatedly?
triggers the brains reward system driving a compulsion to take the drug again and again
feedback to the prefrontal cortex to the VTA regulates the drive to obtain pleasure - overtime this feedback pathway becomes dysregulated impairing decision making
additionally, opioid receptors in the VTA become less sensitive to opioid stimulation - DA production is reduced and the experience of pleasure/opioid effect is diminished
How fast does naloxone restore breathing?
within 2 to 5 minutes
how long does naloxone last?
effects wear off after 30-90 minutes
what are early symptoms of opioid withdrawal?
seen in hours to days
anxiety/restlessness
sweating
rapid rapid respiration
runny nose, tearing eyes
dilated reactive pupils
other: sympathetic/stimulation
brief increase in pain
what are the late symptoms of opioid withdrawal?
days to weeks
runny nose, tearing eyes
rapid breathing, yawning
tremor, diffuse muscle spasms, bone/joint aches
pilo-erection (gooseflesh skin)
nausea and vomiting; diarrhea; abdominal pain
dysphoria
fever, chills
increase WBCs (if sudden withdrawal)
what are the prolonged symptoms of opioid withdrawal?
weeks to 6 months
irritability, fatigue, malaise, psychological/wellbeing (dysphoria, coping, craving)
bradycardia
decreased body temperature
what can be used to treat aches and pains in opioid withdrawal?
NSAIDs (give regularly initially), acetaminophen
what can be used for nausea/vomiting in opioid withdrawal?
dimenhydrinate, haloperidol
what is used to treat insomnia in opioid withdrawal?
non-drug and sleep hygiene measures
trazodone
what can be used to manage the physical symptoms of opioid withdrawal?
clonidine
what can be used to manage sweating associated with opioid withdrawal?
oxybutynin
why should benzodiazepines be avoided in opioid withdrawal?
increase risk of CNS depression/opioid toxicity
how long does opioid withdrawal last?
physical symptoms generally resolve over 5-10 days
psychological symptoms such as dysphoria and insomnia may take longer
what are the s/sx of opioid overdose?
difficulty walking, talking, staying awake
blue lips or nails
very small pupils
cold and clammy skin
dizziness and confusion
extreme drowsiness
choking, gurgling or snoring sounds
slow, weak, or no breathing
inability to wake up, even when shaken or shouted at
what can lower your tolerance for opioids?
taken a break from using
recently been in detox/treatment
recently been incarcerated
started using recently
lung, liver, and other health issues (e.g., asthma, COPD, hep C)
has a recent overdose
which route of administration is the most dangerous for taking drugs
injecting
T or F
if you are going to mix drugs and alcohol, it is better to drink before doing drugs?
false
drugs before alcohol
how strong is fentanyl?
50-100 times more toxic than morphine
lethal dose is 2mg
why is it dangerous to take too much of an opioid?
lose the urge to breath
breathing slows decreasing oxygen to the brain
can lead to permanent brain injury or death if untreated
T or F
naloxone works for non-opioid ODs
false
what is the MOA of naloxone?
displaces opioids at receptors NOT destroyed
what are the key features of an opioid overdose?
unresponsive
slow breathing
may also have: small pupils, snoring or gurgling, blue lips and nails, cold clammy skin
what is the protocol for an opioid overdose?
SAVE ME
- stimulate
- airways
- ventilate
- evaluate
- muscular injection (naloxone)
- evaluate
how do you ventilate someone ODing?
pinch nose
start with 2 breaths
1 breath every 5 seconds x 2 mins = 24 breaths
why is rescue breathing so important in an OD?
crucial to prevent brain injury and death
how do you use naloxone injection?
tap or swirl all medication to the bottom
snap away from you
draw up all fluid into the Vanishpoint syringe
remove most of the air
at 90 degrees into large muscle: thigh (recommended), upper arm, butt
be firm and steady
push the plunger in all the way until you hear a click
when should you consider a second dose of naloxone?
20-30 rescue breaths with no response
2-3 minutes between doses
what are the recommendations regarding naltrexone in OUD?
for patients wishing to avoid long term opioid agonist treatment, provide supervised slow (>1 month) outpatient or residential opioid agonist taper rather than rapid (<1 week) inpatient opioid agonist taper
during withdrawal management, patients should be transitioned to long term addiction treatment to prevent relapse and associated harm
oral naltrexone can be considered as an adjunct upon cessation of opioid use
how does naltrexone work in OUD>
opioid receptor antagonist
blocks the euphoric effects of opioids
what are the risks involved with naltrexone?
increased risk of OD for patients who stop treatment and relapse to opioid use due to decrease tolerance
what are the benefits of naltrexone in OUD?
ease of administration
no induced tolerance during prolonged tx
no potential for dependence/misuse
what are the current guidelines regarding OUD treatment?
1st line: buprenorphine/naloxone (suboxone)
2nd line: methadone
3rd line: slow release oral morphine
what are the available dosage forms of suboxone
2/0.5 mg or 8/2 mg SL tablets
what is sublocade?
buprenorphine extended release injection
SC abdominal monthly injection
what are the receptor effects of buprenorphine?
high affinity for mu opioid receptor
- displaces heroin or other opiates from receptors
- occupies receptor and blocks other opiates effects
- partial agonist at mu receptor
- antagonist at kappa and delta opioid receptors
slow dissociation from opioid receptor
- duration of action increases with increase dose
what is the labelled max of buprenorphine?
24 mg/d
but dosed up to 32 mg/d for some
what is the duration of action of buprenorphine?
increases with increased doses
4 mg = 12 hrs
8-12 mg = 24 hrs
>16 mg = 24-48 hrs
why is buprenorphine safer in OD compared to other opioids?
partial agonism –> opiate ceiling effects
- no further opioid effects above a certain dose
why is suboxone formulated with naloxone?
naloxone oral or SL is not absorbed - no effect unless injected
may negate opiates effects if injected
what are some AEs of suboxone?
common
- headache, pain, withdrawal syndrome
- constipation, nausea, abdominal pain
- insomnia
- runny nose, sweating
other
- flu-like symptoms, muscle aches
- tooth disorder, dyspepsia
- depression, anxiety, nervousness, somnolence, dizziness, paresthesia
what are some DIs of suboxone?
opioids for analgesia: diminished effect
alcohol, BZDs: increased risk of respiratory depression
what are the advantages of suboxone over methadone?
decrease risk of OD
decrease s/e
decrease risk of diversion
decrease DIs
milder withdrawal symptoms when d/c
T or F
methadone is more effective than suboxone?
false
they are equally effective in decreasing illicit opioid use
how to take suboxone?
dissolve under tongue
may take up to 10 minutes to dissolve
avoid eating and drinking during that time
no therapeutic effect if swallowed
when will precipitated withdrawal occur?
30-60 min after 1st dose of suboxone
what is precipitated withdrawal?
buprenorphine displaces opiate agonist from opioid receptor
buprenorphine partially activates receptor compared to full agonists
overall net decrease in receptor activation –> withdrawal symptoms
how can you minimise precipitated withdrawal with suboxone?
delay first dose until moderate withdrawal (COWS 12)
start with low dose
communicate risk
monitor patient
micro-dosing induction
at what COWS score must a patient be below in order to initiate suboxone?
12
what is the theory behind microdosing suboxone?
repetitive administration of very small buprenorphine doses should precipitate opioid withdrawal
buprenorphine will accumulate at the receptor due to long t1/2
over time, an increasing amount of the full agonist will be replaced by buprenorphine at the receptor
when is methadone used over suboxone?
for individuals responding poorly to buprenorphine-naloxone, consider transition to methadone
initiate with methadone when suboxone not preferred option
in which people does methadone seem to have better rention rates?
moderate-severe OUD
heroin addiction
long history of OUD
what are the advantages of methadone over suboxone?
flexible dosing
safer in pregnancy
what is the onset and duration of methadone?
onset: 0.5-1 hour
duration:
- analgesia: 4-8 hrs
- OAT: 22-48 hrs (with repeated dosing)
half-life: 24-36 hrs (can accumulate)
what are ADEs associated with methadone?
QT prolongation
somnolence
agitation
mild cognitive dysfunction
hormonal dysfunction
weight gain
nausea
sweating
constipation
tooth decay
what are DIs of methadone?
CYP3A4 and 2D6
additive QT prolongation
serotonin syndrome
additive CNS depression
T or F
higher doses of methadone are more effective than lower doses
true
what is the dosing of methadone?
most studies suggest >80 mg/d
>120 mg/d may be needed to prevent w/d
when should methadone dosing be adjusted?
no sooner than every 5 days due to long t1/2
when is slow release oral morphine used in OUD?
in patients for whom second line treatment options are ineffective or CI, opioid agonist treatment with slow-release oral morphine can be considered
what are the benefits of SROM compared to methadone?
shorter QTc intervals
decreased heroin cravings
reduced dysthymic symptoms
when should SROM dose be adjusted?
no sooner than q48 hours
what are the benefits of iOAT?
in individuals that are treatment refractory to methadone, prescription diacetylmorphine, administered under the supervision of trained health care providers in a setting is beneficial in reducing
- illicit opioid use
- premature treatment d/c
- criminal activity
- incarceration
- mortality
also improves overall health and social functioning
which iOAT was approved in Canada for use?
hydromorphone injection
