Pain Management: Opioids Flashcards
(129 cards)
1
Q
opiate
A
any of the narcotic alkaloids found in the poppy
including morphine, codeine, and thebaine.
2
Q
opioid
A
any substance, endogenous or synthetic, that produces morphine-like actions which can be blocked by naloxone.
3
Q
thebaine is the precursor to (3)
A
precursor for oxycodone, hydromorphone, oxymorphone
4
Q
3 classes of opioids
A
morphine like
meperidine like
methadone like
5
Q
derivatives of morphine: full agonists (3)
A
heroin
hydromorphone
oxymorphone
6
Q
derivatives of morphine: partial agonists (2)
A
codeine
hydrocodone
7
Q
opioid antagonist examples
A
naltrexone
naloxone
buprenorphine
8
Q
mixed agonist antagonist
A
buprenorphine: acts as an agonist at one subtype of opioid receptor and an antagonist at another.
9
Q
meperidine class
A
fentanyl
sufentanil
alfentanil
10
Q
heroin is morphine with
A
two acetyl groups added to it
diacetyl morphine
11
Q
the active ingredient in heroin is
A
morphine
12
Q
why do people with opioid use disorder prefer heroin to morphine?
A
the 2 acetyl groups make heroin get into the brain faster than morphine does because it is much more lipophilic.
13
Q
fentanyl vs heroin
A
more potent
more lipophilic
gets into the brain faster
14
Q
which type of receptors do opioids work through?
A
G protein coupled receptors
15
Q
true or false: endogenous and exogenous opioids both work through G protein coupled receptors
A
true
16
Q
the opioid receptors
A
mewe
delta
kappa
ORL1
17
Q
Which type of G protein do all 4 of the opioid receptors couple to?
A
Gi
18
Q
opioid receptors are expressed both
A
pre synaptically an post synaptically
19
Q
opioid receptors are coupled to calcium channels on which side of the synapse?
A
pre synaptic terminal
20
Q
when calcium enters the pre synaptic terminal,
A
the axon terminal releases its neurotransmitter into the synaptic cleft.
21
Q
what happens when you activate opioid receptors on pre synaptic terminals?
A
By activating the Gi protein, inhibiting calcium channels and keeping Ca from entering the pre synaptic terminal, which stops NT release. (halting pain transmission)
22
Q
opioid receptors are coupled to potassium on which side of the synapse?
A
post synaptic side
23
Q
Opioid receptors on the post synaptic side do what?
A
open potassium channels, causing K to flood out of the neuron.
24
Q
pre synaptic and post synaptic mechanism act to
A
shut down pain transmission at the level of the synapse
25
By activating the opioid receptors on the presynaptic and postsynaptic terminals,
neuron is inhibited from transmitting a pain signal to another neuron
26
effects of opioids on the CNS(7)
```
analgesia
euphoria
sedation
resp depression
cough depression
n/v
pupillary constriction
```
27
gold standard for treating moderate to severe pain, especially for nociceptive/inflammatory pain
opioids
28
because of ____, you can keep increasing the dose of opioids
tolerance
29
diagnostic tool for diagnosing an opioid overdose
pupillary constriction (armyosis)
30
opioid effects on GI tract (4)
increased tone, decreased motility
delay in gastric emptying
constipation
increase in intrabiliary pressure
31
opioids: pruritis
histamine release from mast cells
32
immune suppression: opioids
occurs with long term use.
Reduced hypothalamic pituitary adrenal (HPA) access and direct effects on immune cells themselves. immune cells have mew opioid receptors.
33
opioids: endocrinopathies
chronic long term use
| decrease circulating sex hormones. can lead to osteroporosis
34
opioids: hyperalgesia
extreme response to pain from chronic prescribing of opioids
35
pure agonists: morphine like
| Scientific name
phenanthrenes
36
example of morphine like pure agonists (phenanthrenes) 7
```
morphine
codeine
oxycodone
oxymorphone
hydromorphone
etorphine
dimorphine
```
37
examples of meperidine-like phenylpiperidines
```
meperidine
fentanyl
alfentanyl
sufentanyl
remifentanyl
```
38
example of methadone-like (diphenylheptanes)
methadone
loperamide
tramadol
tapentadol
39
mixed agonists-antagonist (4)
buprenorphine
butorphanol
nalbuphine
pantazocine
40
buprenorphine and butorphanol
| receptors
partial agonists at mew opioid receptors
| antagonists at kappa opioid receptors
41
nalbuphine and pentazocine
| Antagonize/agonize where?
antagonist at mew receptors
| agonist at kappa receptors
42
mixed agonist-antagonist can be used
as analgesics
43
mainstay treatment for chronic moderate/severe nociceptive or inflammatory pain
pure agonists
44
opioids in neuropathic or functional pain
no efficacy
45
opioids having no clinically relevant ceiling effect to analgesia is related to
tolerance with repeated administration
46
true or false - morphine is superior to other mu agonists
false
| variation exists among all pure agonist
47
MoA morphine
| pre and post synaptic
activation of mu, kappa, and delta.
pre synaptic - block calcium channels and reduce NT release
post synaptic - open K channels, cause hyperpolarization of post synaptic neuron, leading to a decrease in cell firing.
48
PO bioavailability of morphine
25%
| low
49
low bioavailability of morphine means
you have to give a much higher dose po to achieve the same effect that you would IV
50
M6G
the active metabolite of morphine
51
M3G
neurotoxic metabolite of morphine
if metabolism of morphine is changed, we have to be careful about M3G.
52
renal impairment and morphine
you will have a buildup of m6G and m3G.
| toxicity.
53
half-life of morphine
~2 hr
54
adverse effects of morphine
```
resp depression
N/V
dizziness
mental clouding
dysphoria
pruritis
constipation
urinary retention
hypotension
```
55
Contraindications for morphine are related to (4)
impaired liver function
impaired response function
asthma
hypotension
56
drug:drug interactions with morphine
any drugs with major significance relating to additive effects of morphine.
57
half lives of oxy, hydromorphine, oxymorphone, codeine
relatively short
58
which opioid is preferred for those with renal insufficiency and why?
hydromorphone as it does not have a lot of active metabolites.
59
notable side effect of hydromorphone
chest pain
60
codeine metabolism
phase I via CYP2D6
| converts to morphine
61
ultrametabolizers of codeine
cyp2d6
codeine poisoning
converting to morphine at dangerous levels
may be seen in breastfed infants
62
meperidine class drug example
fentanyl
63
half life of meperidine
short
64
meperidine as compared to morphine
less constipation
| more lipophilic and gets to the brain quicker, doesn't effect peripheral tissues.
65
meperidine for chronic pain
not recommended because of the metabolite toxicity
66
med that is contraindicated with meperidine
MAOI
67
Meperidine and tachycardic patients
contraindicated. can raise HR further
68
routes of admin for fentanyl
paraenteral
transdermal
transmucosal
69
potency of fentanyl
high, about 100x morphine potency
70
half life of fentanyl
high
71
lipophilicity of fentanyl
high
| which makes it a good candidate for transdermal route.
72
why isn't there po fentanyl?
it goes through significant first pass effect and does not reach systemic circulation
73
T or F: fentanyl and its congeners are devoid of active metabolites
true
74
carfentanyl potency
1000x morphine
| 100x fentanyl
75
why is fentanyl safe to give those with renal impairment?
lack of active metabolites
76
advantages of fentanyl (4)
speed of analgesia in the setting of spontaneous breakthrough pain (given transmucosal)
transdermal
preferred to morphine in renal insufficiency
less prone to constipation
77
who cannot be prescribed transdermal or oral transmucosal fentanyl?
opioid naive patients
78
transdermal fentanyl is inappropriate for what kind of pain?
acute, intermittent, or mild
79
transmucosal fentanyl is always dosed
in the lowest dose in an opioid tolerant patient
80
methadone is
a long acting agonist
81
half life of methadone
20-35 hours
82
does methadone have active metabolites?
no
83
opioids safe for renal impaired patients
hydromorphone
fentanyl
methadone
84
EKG changes with methadone
possibility of QTc interval prolongation
85
neuropathic pain and methadone
more effective than other opioids
86
why does methadone produce less tolerance?
because it antagonizes NMDA receptors, altering glutamate levels in the CNS. tolerance does not develop at the same rate.
87
why is methadone usable for neuropathic pain?
because it antagonizes NMDA receptors, altering glutamate activity.
88
pharmacokinetic drug:drug interactions of methadone
many drugs induce or inhibit CYP3A4
| methadone itself induces 3A4
89
pharmacodynamic drug:drug interactions of methadone
- anything that may cause CNS depression
| - anything that may cause QTc prolongation
90
what are the two opioids that are lipophilic enough to be given transdermally?
buprenorphine
| fentanyl
91
which 2 opioids are not available PO?
buprenorphine
| fentanyl
92
which 4 opioids can be given extended release?
hydromorphone
morphine
oxycodone
oxymorphone
93
which opioids can be given as suppositories?
hydromorphone
| morphine
94
which 2 opioids are not offered injectable?
codeine
| oxycodone
95
which is the only opioid that is given transmucosally?
fentanyl
96
which opioids stand out for breakthrough pain?
fentanyl
| methadone
97
opioid tolerance
progressive loss of effect with sustained administration of an opioid receptor agonist
98
tolerance can be up to
30-fold
99
tolerance to a particular opioid is comprised of either
- tolerance unique to that opioid
| - tolerance that extends to other opioid agonists
100
cross tolerance
tolerance that extends to other opioid receptor agonists
101
different responses to an opioid develop tolerance at different rates, ie:
tolerance to respiratory depression happens quickly, while tolerance to constipation never really happens.
102
tolerance to a drug is combatted with
higher doses
| watch for adverse effects
103
opioid induced tolerance (4) characteristics
progressive decrease in efficacy
increased dose decreases pain
adverse effects with increased dosing
*decreased sensitivity to opioid analgesics(
104
opioid induced hyperalgesia (4) characteristics
paradoxical increase in sensitivity to painful stimuli
increased dose increases pain
may be a different pain altogether
*increased sensitivity to pain*
105
why is methadone spot blank on equianalgesic chart?
because tolerance is nonlinear in methadone. you'll need to see a chart specific to methadone.
106
what is the issue with equianalgesic tables?
- single dose studies in opioid naive patients with acute pain
- variables such as bioavailability are not taken into account
- undirectional vs bidirectional equivalencies *pay attention to sedation when going from one drug to another
107
when changing from IR to ER
start with the same daily total dose
108
if changing from one opioid to another, what must you do with the new dose?
reduce the new med dose by 25-50% to begin with
109
breakthrough pain types (4)
spontaneous
incidental volitional
incidental nonvolitional
end of dose
110
volitional pain
pain under the patients control. ie raising arm after shoulder surgery would cause volitional pain
111
Non volitional pain
unpreventable pain. ie coughing after surgery
112
management of spontaneous, volitional, and volitional breakthrough pain
IR opioid PRN
113
management of end of dose breakthrough pain
increase the dose or frequency of the around the clock analgesic
114
breakthrough pain dosinf
10-15% total daily dose of the same opioid
115
management of volitional pain
consider premeditating 30-45 min in advance of anticipated pain trigger
116
what medications might you consider in the case of spontaneous or non volitional pain that comes on quickly
transmucosal fentanyl
or
PO methadone
117
onset of analgesia is directly related to
lipophillicity
118
oral transmucosal fentanyl black box warning
- only dosed by titration, beginning with 100 mcg
| - use only in opioid tolerant individuals
119
opioid receptor antagonists
naloxone
naltrexone
methylnaltrexone
alvimopan
120
short acting opioid receptor antagonist
naloxone
121
long acting opioid receptor antagonist
naltrexone
122
naloxone and naltrexone are antagonists of
mu kappa and delta
123
naloxone is given ____ while naltrexone is given ____
naloxone - IM, IV, intranasal
| naltrexone - oral
124
naloxone and naltrexone block ____ and exacerbate ____
block stress induced analgesia
| exacerbate clinical pain
125
what rebound effects do you need to monitor for after use of naloxone
htn
tachycardia
ventricular arrhythmias
126
what can naloxone and naltrexone also reverse
gi immotility/constipation
127
opioid receptor antagonists that do not cross the BBB
| and what does this mean?
methylnaltrexone
alvimopan
adverse effects may be reversed but analgesia will not ie you can relieve constipation without reversing pain control
128
buprenorphine can be abused and require naloxone. how many attempts of naloxone may it take?
3-4
129
Suboxone SL
| how it works
you'll only feel the agonist, not the antagonist part.
it's buprenorphine and naloxone.
if you crush it and inject it, you can't get high bc the naloxone blocks it.
