Opioid Agonist-Antagonists & Antagonists (Exam II) Flashcards
(79 cards)
1
Q
What is the primary indication for opioid agonist-antagonists?
A
- Used if unable to tolerate full agonist
2
Q
Name the four advantages of opioid agonist-antagonists.
A
- Analgesia
- Less respiratory depression
- Low dependence potential
- Ceiling effect (prevents ODing)
3
Q
Opioid antagonists bind to their receptors how?
A
Mu: partial effect (agonist) or No effect (comp. antagonist)
K and delta: partial effect (agonist)
4
Q
How potent is Pentazocine?
A
- 1/5 as potent as morphine and Nalorphine
5
Q
What is the gold standard for opioid agonist-antagonists?
A
Nalorphine
6
Q
What receptors does pentazocine bind to?
What type of activity does it exhibit?
A
- κ & δ receptor partial agonist activity
7
Q
How is pentazocine excreted?
A
- Glucuronide conjugates in the urine.
8
Q
Which opioid agonist-antagonist crosses the placental barrier causing fetal depression?
A
Pentazocine
9
Q
What is the chronic pain dose of Pentazocine?
What dose and route would be equivalent to morphine 10mg?
A
- 10 - 30mg IV or 50 mg PO
- 20-30mg IM = 10mg morphine
10
Q
Where is butorphanol excreted?
A
Bile > urine
11
Q
What receptors does butorphanol bind to?
A
- κ = analgesia & anti-shivering
- μ (low)
- Sigma = σ (low)
12
Q
Sigma (σ) receptors are associated with what side effect?
A
Dysphoria
13
Q
2 to 3 mg of butorphanol is equivalent to _____ mg of morphine.
A
10
(depression of ventilation)
14
Q
Which receptor has a moderate affinity for Butorphanol’s effects to mitigate shivering and produce analgesia?
A. Mu
B. Kappa
C. Sigma
D. Delta
A
B. Kappa
15
Q
Pentazocine Side effects: (5)
A
- sedation
- diaphoresis
- dizziness
- dysphoria (high doses)
- increased HR, BP, PArtPress, LVEDP with high doses
16
Q
By what route is butorphanol rapidly and completely absorbed?
A
Intramuscular
17
Q
Elimination half-time of ____ is 2-3 hrs and it is 2.5-3.5 hrs in _____
A
Pentazocine
Butorphanol
18
Q
What drug is an excellent choice for cardiac catheterization patients?
Why?
A
- Nalbuphine
- No increase in BP, pBP, HR or Atrial filling pressures
19
Q
What receptors does nalbuphine bind to?
How potent is it?
A
- μ receptor agonist that is equipotent to morphine.
20
Q
Which agonist-antagonist has 50 times greater μ receptor affinity than morphine?
A
Buprenorphine
21
Q
What is buprenorphine’s onset?
Duration?
A
- 30min onset
- 8 hour duration
22
Q
0.3 Mg IM of Buprenorphine =
A
10 mg of morphine
23
Q
What is buprenorphine’s greatest use?
A
- Opioid use disorder (has low risk of abuse)
24
Q
What are 3 side effects of Buprenorphine?
A
- Pulmonary edema
- withdrawal
- low risk of abuse
25
Which two drugs have resistance to naloxone?
- Buprenorphine and Bremazocine.
26
Which opioid has high incidence of dysphoria and is therefore not utilized clinically?
Nalorphine
27
which drug is 25% bound to protein, ...
Meptazinol
28
which drug has 2x potency than morphine at the K receptors?
Bremazocine
29
Which drugs are pure μ-opioid receptor antagonists?
- Naloxone
- Naltrexone
- Nalmefene
30
Which Opioid Agonist-Antagonist is more potent than Morphine?
A. Nalorphine
B. Nalbuphine
C. Buprenorphine
D. Meptazinol
Buprenorphine
31
What receptors is naloxone effective on?
- μ, κ, δ (non-selective)
32
Which drugs are competitive antatgonists for µ opioid receptors and has high affinity for it?
Naloxone, Naltrexone, and Nalmefene
33
What **non-opioid** uses does naloxone have?
- ↑ contractility for shock
- Antagonism of general anesthesia **at high doses.**
34
What is the dose for Naloxone?
1 to 4 µg/kg IV
5 µg/kg IV continuous infusion
35
What dose of naloxone is use for shock?
- > 1mg/kg IV
36
How long does Naloxone last?
- **30 - 45 minutes**
*Often needs redosing for overdoses*.
37
Metabolism of this drug is by the liver, has an elimination half-time of 60-90 min and the hepatic first pass is 1/5th PO
Naloxone
38
What are the possible side-effects of naloxone? (5)
- **Analgesia reversal**
- **N/V**
- ↑ SNS ( ↑ HR, BP)
- Pulmonary edema
- dysrhythmias (v-fib)
39
What use does naltrexone have?
How long does it last and how is it adminstered?
- EtOH
- Given PO (more effective) lasts for 24 hours.
40
How does nalmefene's potency compare to naloxone?
What is it's dose and max?
- Nalmefene = naloxone
- 15 - 25 mcg IV (max of 1 mcg/kg)
41
Half-time of this drug is 10.8 hrs
Nalmefene
42
What is methylnaltrexone's use?
- Anti-emetic (antagonizes N/V from opioids)
- promotes gastric emptying
43
What is Alvimopan and what is it used for?
How is it metabolized?
Why can't it be used long term?
- μ-selective PO peripheral opioid antagonist for **post-op ileus**.
- Gut flora metabolism
- CV problems with long term use
44
What are the abuse-resistant opioid formulations?
- Suboxone (buprenorphine + naloxone)
- Embeda (long-release morphine + naltrexone)
- OxyNal (oxycodone + naltrexone)
45
What opioid-agonists have a significant effect on volatile anesthetics?
- Fentanyl & it's derivatives decrease the MAC of volatiles by 50% or greater.
46
Fentanyl 3 μg/kg IV 25-30 min prior to incision will have what effect on which volatile gasses?
- 50% MAC reduction for isoflurane and desflurane.
47
Sufentanil decreases MAC with Enflurane by
70-90%
48
Alfentanil decreases MAC by
up to 70%
49
Remifentanil decreases MAC by
50-91%
50
Which opioid partial agonists have an effect on decreasing MAC?
- Pentazocine
- Butorphanol
- Nalbuphine
51
Where are receptors targeted with opioid neuraxial anesthesia?
- Opioid receptors of the **substantia gelatinosa.**
52
What is general rule of dosing for epidural opioids?
- Dose = 5 - 10 x normal
53
Name the three blanks
54
Diffusion of opioids across the _____ ______ results in systemic absorption.
dura mater
55
Neuraxial opioids do not cause
Sympathectomy
sensory block
weakness
56
Where can opioids be injected during an epidural that results in systemic absorption?
What should be done if this occurs?
- Epidural venous plexus
- Add epi or neo to the infusion.
57
Spinal/Intrathecal/Subarachnoid Block (SAB) are ___
all interchangeable
58
Epidural uptake takes place in
slide 34
Uptake in the **fat**
in the **venous** plexus = systemic aborption
59
The goal of the epidural is to ____
have it cross the dura and enter the or bath the CSF
60
Fent epidural
Peak:
Strenght compared to morphine
Peak: 20 min
Fent is 800x stronger than morphine
61
Sufentanil epidural
Peak:
Strenght compared to morphine
Peak: 6 min
Sufentanil is 1600x stronger than morphine
62
What is Cephalad movement (in regards to epidurals)?
Cephalad Movement = the movement of drug/injectate **up the spinal cord towards the brain**.
63
What drug attribute decreases cephalad movement?
- the higher the Lipid solubility --> the less cephalad movement (up)
64
T1 - T4 are our ____ _____
Cardiac accelorators
64
PCA doses for Fentanyl
Basal rate:
Bolus dose:
Bolus interval (min):
Basal rate: 0 - 60 mcg/hr
Bolus dose: 20 - 50 mcg
Bolus interval (min): 5 - 10 min
65
What is shown here?
The lack of oversedation and dip into longer pain with PCA administration compared to PRN administration
66
PCA doses for morphine
Basal rate:
Bolus dose:
Bolus interval (min):
Basal rate: 0-2 mg/hr
Bolus dose: 1-2 mg
Bolus interval (min): 6-10 min
67
PCA doses for Hydromorphone
Basal rate:
Bolus dose:
Bolus interval (min):
Basal rate: 0-0.4 mg/hr
Bolus dose: 0.2-0.4 mg
Bolus interval (min): 6-10 min
68
________ exhibits much more cephalad movement than __________.
Why is this?
- Morphine ; fentanyl
- Fentanyl and it's derivatives are much more lipid soluble and thus exhibit **less** cephalad movement.
69
What can cause cephalad movement? (besides characteristics of drugs themselves)
Coughing and/or straining
70
When would epidural CSF levels peak for the following drugs:
- Fentanyl
- Sufentanil
- Morphine
- Fentanyl - 20min
- Sufentanil - 6min
- Morphine - 1-4 hours
71
When would epidural administered plasma levels peak for the following drugs:
- Fentanyl
- Sufentanil
- Morphine
- Fentanyl - 5-10 min
- Sufentanil - 5 min or less
- Morphine - 10 - 15 min
72
For Neuraxial morphine
CSF peak time:
Plasma peak time:
cervical/CSF levels maintained for:
CSF peak time: 1-4 hrs
Plasma peak time: 10-15 min
cervical/CSF levels maintained for: 1-5 hrs
73
When would epidural administered intrathecal/cervical CSF levels peak for the following drugs:
- Fentanyl
- Sufentanil
- Morphine
- Fentanyl - N/A
- Sufentanil - N/A
- Morphine - 1 - 5 hours (due to cephalad movement)
74
What is the most common side effect from neuraxial opioid administration?
Why does this occur?
- Pruritis
- Cephalad migration to **trigeminal nucleus**
75
What are the treatments for pruritis induced by neuraxial opioids? (4)
- 10mg **Propofol**
- Naloxone
- Antihistamines
- Gabapentin
76
Name the list (its a lot) of side effects that can occur with neuraxial opioid administration. (8)
- Pruritis
- N/V
- Urinary retention (males)
- Respiratory depression
- Sedation
- Skeletal muscle rigidity
- Herpes virus reactivation
- Neonatal effects.
77
If neuraxial opioids induced a reemergence of a herpes virus, how long would this occur after opioid administration?
- 2 - 5 days
78
What sign would indicate respiratory depression from neuraxial opioid administration?
What is the treatment?
- ↓LOC from ↑CO₂
- Naloxone 0.25 μg/kg/hr IV
