Lecture 9 (Exam 2) - Opioid Agonist/Antagonist & Opioid Antagonists Flashcards

1
Q

What is pentazocine used for and at what dose? (IV, IM, PO)

A

Moderate chronic pain
IV: 10-30mg
IM: 20-30mg
PO: 50mg

slide 14

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2
Q

What is the PO dose (50mg) of Pentazocine equivalent to?

A

60mg Codeine

slide 14

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3
Q

What is the IM dose (20-30mg) of Pentazocine equivalent to that produces similar sedation and depression of ventilation?

A

10mg Morphine

slide 14

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4
Q

Why do we like Pentazocine for epidural analgesia?

A

Bc it has shorter duration < morphine

slide 14

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5
Q

Pentazocine s/e are similar to morphine’s.
What can it cause at high doses?
What cardiac effects do you see?

A

Dysphoria ✨
❤️: ⬆in HR, BP, pulmonary artery BP, LVEDP

slide 14

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6
Q

What must you consider when giving Pentazocine to pregnant women?

A

It crosses the placental barrier and can cause fetal depression. 👶🏻

slide 14

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7
Q

Is Butorphanol (Stadol) more potent than pentazocine? (Agonist and Antagonist effects)

A

Yes.
Agonist: 20x > (more potent than morphine)
Antagonist: 10-30x >

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8
Q

Butorphanol’s (Stadol) affinity for mu receptors to produce antagonism is ____.
It also has a ____ affinity for sigma, so dysphoria ✨ is low.
Its affinity for Kappa receptors is ______.

A

Mu: low
sigma: low
kappa: moderate ❄️

slide 15

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9
Q

What is the IM dose for Butorphanol (stadol) and how many Mg of morphine is this equivalent to?
And why is it given this route?

A

-2-3mg IM = 10mg morphine (depression of ventilation)
-absorbed immediately

slide 15

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10
Q

Which receptor has moderate affinity for Butorphanol (stadol) to prevent shivering and analgesia?

A

Kappa receptor! ❄️

slide 15 (he asked this question on a slide)

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11
Q

Butorphanol is metabolized in the liver, eliminated via _____ > urine and its E1/2 is ____ to ____ hours.

A

bile; 2.5-3.5 hours

slide 16

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12
Q

S/E of Butorphanol (stadol). (❤️, ✨, 💦)

A

sedation, nausea, diaphoresis 💦, dysphoria ✨, depresses ventilation, W/D can occur

❤️: ⬆ BP, PA BP, CO

slide 16

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13
Q

What can Butorphanol (stadol) cause synergistic effects with?

A

Other opioid agonists.

slide 16

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14
Q

Castillo wants us to know the least and most of the table (flip card)

Alfentanil:
most - % ionized & protein binding
least - clearance & Vd

Remifentanil:
most- clearance (4000)

Fentanyl:
most - Vd & effect site (brain equilibrium time)

A
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15
Q

Mu 1: “slow, cold, cant see, cant pee, but happy”
Mu 2: “cant breathe, cant poo & im addicted too”
Kappa: “sad, sleepy, peeing, cant see”
Delta: “ cant breathe, cant pee, cant poo & addicted too” (similar to Mu2)

A
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16
Q

What are the 7 Opioid Agonist-Antagonists from lecture?

A
  1. Pentazocine
  2. Butorphanol
  3. Nalbuphine
  4. Buprenorphine
  5. Nalorphine
  6. Bremazocine
  7. Dezocine

(Slide 11)

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17
Q

When are Opioid Agonist-Antagonists used?

A

They are used if unable to tolerate a pure agonist.

(Slide 12)

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18
Q

What receptors do Opioid Agonist-Antagonists bind to?

A
  1. µ receptors: partial effect (agonist) or no effect (competitive antagonist)
  2. Κ and δ receptors: partial effect (agonist)

(Slide 12)

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19
Q

What are the generalized side effects of Opioid Agonist-Antagonists?

A

They are the same as opioid agonists + dysphoric reactions. 😒

(Slide 12)

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20
Q

What are some of the advantages of Opioid Agonist-Antagonists?

A

Analgesia
Limited depression of ventilation
Low potential for physical dependence
Ceiling effect prevents additional responses

(Slide 12)

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21
Q

Pentazocine
1. What receptors does it bind to?
2. Will you have withdrawal symptoms?
3. It is ____ as potent as Nalorphine.
4. What is it antagonized by?
5. How is it excreted?

A
  1. Agonist effects on δ and κ receptors with weak antagonist activity
  2. Yes
  3. 1/5th as potent as Nalorphine
  4. Antagonized by Naloxone
  5. Glucoronide conjugates = urine
    Extensive hepatic first pass (20% available post PO)
    Elimination half-time: 2 to 3 hours

(Slide 13)

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22
Q

Why are opioid agonists used?

A

They are used to control acute or chronic pain.
Some are used for diarrhea & cough.

(Video 00:12)

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23
Q

Opioids bind to opioid receptors in the ____, _____, & ____.

A

Brain, spinal cord, & GI tract

(Video 00:43)

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24
Q

Nalbuphine, an opioid agonist-antagonist has equipotency with what gold standard drug?

A

Morphine, so 10 mg of Nalbuphine = 10 mg morphine. (Slide 17)

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25
Q

Which agonist antagonist opioid is good to use in patients with cardiovascular dz?

A

Nalbuphine. This drug does not cause an increase in BP, pulm pressures, HR, or atrial pressures. (Slide 17)

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26
Q

Nalbuphine is _____ as potent as Nalorphine.

A

The antagonist effect of Nalbuphine is 1/4th as potent as Nalorphine. (Slide 17)

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27
Q

With EPIDURAL admin of Fentanyl, Sufentanil, and morphine, what are their individual CSF Peak times?

A

Fentanyl: 20 min
Sufentanil: 6 min
Morphine: 1-4 hours

(slide 35)

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28
Q

With EPIDURAL admin of Fentanyl, Sufentanil, and morphine, what are their individual Plasma Peak times?

A

Fentanyl: 5-10 min
Sufentanil: < 5 min
Morphine: 10-15 min

All times are similar with IM admins

(slide 35)

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29
Q

Which opioid agonist - antagonist has a long duration and 50 x more affinity with the receptor than morphine?

A

Buprenorphine. Very high receptor affinity and slow dissociation. Nice long lasting drug but also has a prolonged resistance to Naloxone! (Slide 18)

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30
Q

Buprenorphine dosing: ______ mg IM = 10 mg morphine.

A

0.3 mg IM, onset in 30 min. Duration 8 hrs. (Slide 18)

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31
Q

Types of pain that Buprenorphine is indicated for?

A

Moderate to severe pain in the post op period, cancer, renal colic, and MIs. (Slide 18)

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32
Q

Side effects of Buprenorphine?

A

Pulmonary edema, drowsiness, N/V, depression of ventilation, withdrawal. (Slide 18)

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33
Q

With INTRATHECAL admin of Fentanyl, Sufentanil, and morphine, what are their individual Cervical Level migration expectations?

A

Fentanyl: minimal
Sufentanil: minimal
Morphine: 1-5 hours cephalad migration can be expected

(slide 35)

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34
Q

Nalorphine is not used as an opioid agonist antagonist because of?

A

High incidence of dysphoria with sigma receptor activation. (Slide 19)

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35
Q

Bremazocine has a receptor affinity for _____ receptors that is ____ more potent than morphine

A

Kappa, 2x (slide 19)

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36
Q

______ is similar to Nalbuphine, in that they both do not exhibit cardiovascular effects.

A

Dezocine (slide 19)

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37
Q

You start an epidural and have since administered an opioid agonist. The pt begins complaining of itching. This is aka ________.

Which pt populations do you expect to this s/e more commonly in?

What is the cause of this?

Treatment?:

A

pruritis
OB
Cause: cephalad migration to trigeminal nucleus
Rx: Naloxone (will fully reverse the opioid tho*), antihistamines, and gabapentin, and apparently propofol

(slide 36)

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38
Q

Dezocine IM dose?

A

10 - 15 mg IM, rapidly absorbed or 0.15 mg/kg IM. (Slide 19)

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39
Q

100 mg of Meptazinol is = to ____ mg of morphine.

A

100mg Meptazinol = 8 mg morphine. (Slide 19)

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40
Q

Meptazinol has a low protein binding of ____ %.

A

25% (slide 19)

41
Q

True or False:
- Neuraxial opioids can cause N/V
- Neuraxial opioids cause urinary retention more in females

Bonus: why does urinary retention occur?

A

True
False; occurs more in males

UR occurs d/t interaction at sacral spinal cord with PNS and peripheral outflow

(slide 36)

42
Q

So we all know opioids make our pts STFU and cause ventilation depression. How long will EARLY s/s of vent depression? How long are DELAYED s/s?

What’s are most reliable s/s of ventilation depression?

Rx (dose)?

A

Early: within 2 hours

Delayed: 6-12 hours (most likely will be seen with Morphine specifically)

Most reliable s/s: ⬇️ LOC secondary to………………..HYPERCARBIA

Rx: Narcan of 0.25 mcg/kg/hr IV; be sure to monitor EtCO2

(slide 37)

43
Q

Besides sedation, pruritis, vent depression, N/V, Urinary retention, what else do some opioid agonists (like Fentanyl) cause?

CNS ___________, especially in the _______ causing…, which can make it difficult to _________.

________ activity. We treat this with…

A

CNS excitation, especially in the thorax causing skeletal muscle rigidity which needs to be considered because this can make it difficult to ventilate**

Seizure activity* - make sure to have benzo’s or propofol PRN

(slide 37)

44
Q

You’re taking care of Ms. Funkibritches who has a hx of HSV-2, and administer an epidural opioid. What should you warn her about post-op days 2-5?

A

Herpes simplex viral reactivation secondary to your neuraxial opioid you administered. (She should be resting anyways)

(slide 38)

45
Q

You’re following up with post-op care for a something y/o mother who underwent a C-section, whom you had administered a neuraxial opioid pre-op. But she’s concerned that she won’t be able to breastfeed her new baby. What should you tell her?

A

Don’t worry momma. Baby will be fine breastfeeding as neuraxial opioids do not affect the she-brew

(slide 38)

46
Q

Which has a longer half-time, Naloxone or Nalmefene?

A

Nalmefene (10.8 hours)
Naloxone’s half-time is 60 to 90 minutes
Slide 25

47
Q

What is naltrexone typically used for?

A

Alcoholism
Slide 25

48
Q

What is the duration of Naltrexone?

A

24 hours
Slide 25

49
Q

What is the dose for Nalmefene?

A

15 to 25 mcg IV (q 2 to 5 minutes)
OR
1 mcg/kg
Slide 25

50
Q

Nalmefene is equipotent to…

A

Naloxone
Slide 25

51
Q

Is Methylnaltrexone ionized or nonionized?

A

Highly ionized
Slide 26

52
Q

This opioid antagonist promotes gastric emptying and antagonizes nausea/vomiting

A

Methylnaltrexone
Slide 26

53
Q

What is the newer, mu-selective PO peripheral opioid antagonist that is used mainly for post-op ileus?

A

Alvimopan
Slide 26

54
Q

Where is Alvimopan metabolized?

A

Gut Flora
Slide 26

55
Q

What is a risk of using Alvimopan long term?

A

Adverse CV Events
Slide 26

56
Q

What are the three tamper/abuse-resistant opioids discussed in class?

A

Suboxone
Embeda
OxyNal
Slide 27

57
Q

Buprenorphine plus naloxone…

A

Suboxone
Slide 27

58
Q

Extended release morphine plus naltrexone…

A

Embeda
Slide 27

59
Q

Oxycodone plus naltrexone…

A

OxyNal
Slide 27

60
Q

what are the 3 pure µ opioid receptor competitive antagonists with no agonist activity discussed?

A

Naloxone, Naltrexone, and Nalmefene

(slide 22)

61
Q

For the 3 Opioid Antagonists discussed in class to be considered a “Competitive Antagonists” what 2 things must be present in the body?

A
  1. An opioid
  2. Must have a large enough dose of the antagonist drug to able to outcompete/displace the opioid from the receptor site

(slide 22)

62
Q

Which Opioid Antagonist is a nonselective antagonist with all 3 opioid receptors?

A

Naloxone

(slide 23)

63
Q

Lungs are __________ and affect the drug’s pharmacokinetics’ _____________ phase (i.e. association and dissociation from plasma proteins and diffusion rates)

A

Reservoirs

Dispositional

(Lung First Pass slide)

64
Q

Removal of endogenous compounds from the pulmonary arterial blood is known as…

A

Pulmonary Uptake/Extraction

(Lung first-pass slide)

65
Q

Define the First Pass Effect

A

Drugs gets retained/accumulated and removed/cleared/metabolized at a specific location in the body that results in a reduced concentration of the active drug upon reaching its site of action

(Lung First-Pass slide)

66
Q

What are the uses of Naloxone (Narcan)?

A
  • opioid-induced depression in post op
  • neonate* (from mom)
  • opioid overdose
  • detect dependence (will require more)
  • Hypovolemic/septic shock
    (It Increased myocardial contractility)
  • Antagonism of general anesthesia (high doses)**

(slide 23)

67
Q

What opioid is most known for its Lung first-pass effect in its metabolism?

(HINT): Castillo mentioned this one specifically in lecture

A

Fentanyl

(Lung first-pass slide; Castillo)

68
Q

What do we need to remember when giving Naloxone to opioid OD in a pregnant mother?

A

It crosses the placental barrier and if mom goes into withdrawals so will the fetus.

(slide 23)

69
Q

What does neuroaxial means?

A

That does not involve brain and only involves axial component of the spinal cord.
Slide 31

70
Q

Neuraxial opioids are used in _______ and _______ space.

A

Epidural and subarachnoid space (spinal according to lecture)
Slide 31

71
Q

Why do we use Neuraxial opioids?

A

It is used for acute or chronic pain management.
Slide 31

72
Q

Where does neuraxial opioid work in spine and its receptor?

A

It works in substantia gelatinosa (lamina II) of spinal cord and work in mu receptor.
Slide 31

73
Q

What is Naloxone’s:
- Dose:
- Dose during Intra-op:
- Dose during Post-op:
- Dose with continuous IV Infusion (and dose with shock infusion):
- Dose with epidural infusion:

A
  • Dose: 1 to 4 µg/kg IV
  • Intra-op: 40-80mcg
  • Post-op: 40-80mcg
  • 5 µg/kg IV continuous infusion
    (> 1 mg/kg IV (shock))
  • 0.25 µg/kg/hour IV Epidural

(slide 24 and Slide 2 in additional notes)

74
Q

Do you see sympathectomy, sensory block, or weakness associated with Neuraxial opioids?

A

No, It only helps with pain.
Slide 31.
( When we do spinal, we go through our skin, fat, ligamentum flavum and spinous ligament until we reach to epidural space)
Slide 31

75
Q

What is Naloxone’s:
-Onset:
-Duration:
Metabolism’s
- Elimination 1/2 time:
- 1st pass:

A

Onset: 1-5min
Duration: 30 min (30-45)
Metabolism: Liver (glucuronic acid)
- E1/2 time: 60-90 min
- Hepatic first pass: 1/5th PO
(Naloxone is absorbed orally, but metabolism during its first pass through the liver renders it only one-fifth as potent as when administered parenterally.)

(slide 24 and Slide 2 in additional notes, Pg. 437)

76
Q

What are the names that can be referred to subarachnoid space?

A

intrathecal space and spinal space.
Slide 31
(SAB –>Subarachnoid block is spinal block)
Slide 31

77
Q

What’s Naloxone’s Side Effects:

A
  • reversal of analgesia*
  • N/V** (If given too fast)
  • increased SNS (HR, BP, pulmonary edema, cardiac dysrhythmias [v-fib])

(slide 24)

78
Q

When giving Naloxone, HOW should we give it to help prevent some side effects?
Also, due to its duration of effect, what should we consider?

A

SLOW (over 2 to 3 minutes)

Since duration is only approx. 30min, may have to do an infusion.

(slide 24, pg. 437)

79
Q

Why is the dose given via epidural 5 to 10x more?

A

The drug need to cross the dura
(unless we give spinal then we give lower dose)
Slide 32

80
Q

Drugs given via epidural _____ into dura and may cause _______ absorption.

A

diffuse and systemic absorption
Slide 32

81
Q

Fentanyl and sufentanil is highly ________.

A

Lipophilic ( so they diffuse more, so their onset and duration of action is not too long)
Slide 32

82
Q

Why morphine does not diffuse across dura faster?

A

Morphine is not as non-ionized fentanyl and sufentanil hence it has slower onset but longer duration of action.
Slide 32

83
Q

When meds are given via epidural where does the absorption occur?

A

epidural fat and systemic absorption via epidural venous plexus.
Slide 33

84
Q

What can you do to prevent the systemic absorption of the medication given via epidural?

A

Add epinephrine or phenylephrine into our solution.
(this shrinks venous plexus and the medication stays in epidural space longer)
Slide 33

85
Q

Where do we want our epidural medication to work in spine?

A

We want meds to diffuse across the dura to CSF
( where we get attachment of mu1, mu2, kappa, and delta occurs in substantial gelatinosa.)
Slide 33

86
Q

What is the lipid solubility of fentanyl compared to morphine and when does it peak?

A

800x more lipid soluble than morphine.
Peaks in 20 mins.
Slide 33

87
Q

What is the lipid solubility of sufentanil compared to morphine and its peak time?

A

1600x more lipid soluble than morphine in the epidural space.
Peak: 6 mins.
(sufentanil works quickly when we give epidural for moms vs when we give fentanyl to hip surgery patients. Great for moms, they can walk and does not cause sympathectomy. )
Slide 33

88
Q

Does cephalad movement in CSF occur with subarachnoid/spinal/intrathecal uptake?

A

Yes, upward movement of CSF occurs depend on lipid solubility of the meds.
Slide 34

89
Q

Since fentanyl and sufentanil is very lipid soluble will the meds diffuse out of CSF or move up the spinal region?

A

Fentanyl and sufentanil diffuse out of CSF to spinal region and less medication will have a cephalad movement occur via CSF.
(It will affect HR as T1 and T4 are cardiac accelerators and also affect breathing as C3,C4,C5 and C6 controls diaphragm.)
Slide 34

90
Q

Does cephalad movement occur with morphine?

A

Yes, morphine being more water soluble stays in CSF longer and more cephalad movement occurs.
( morphine is less lipid soluble so less movement of meds go to spinal cord.)’
Slide 34

91
Q

What is possible with an abrupt withdrawal after prolonged exposure to opioids?
(long term, not just 1 operation).

A

Immunosuppression

Slide 28

92
Q

Is an opioid allergy more a proven fact or myth?

A

More so a myth. Only 3 documented cases to date.
People associate the common side effects as “allergies”.

Slide 28

93
Q

Per Dr. Castillo what is the Minimum Alveolar Concentration needed to be in stage 3 of anesthesia?

A

100%

Slide 29

94
Q

What is given that decreases MAC of Iso or Desflurane to 50%?

A

Opioid Agonists
Fentanyl 3mcg/kg IV 25-30 minutes before surgical incision.

Slide 29

95
Q

What are the effects on MAC with the following opioid agonists?
Sufentanyl
Alfentanyl
Remifentanyl

A

Sufentanyl decreases MAC with Enflurane by 70-90%
Alfentanyl can decrease MAC up to 70%
Remifentanyl can have a 50-91% decrease in MAC

Slide 29

96
Q

Not sure if we need to know this or not for this exam but here ya go:

MAC percentages for the following volitiles
Isoflurane
Sevoflurane
Desflurane

A

Isoflurane: 1.2%
Sevoflurane: 2%
Desflurane: 6%

Mentioned during slide 29

97
Q

What are the Patient-Controlled Analgesia doses for:
Morphine
Hydromorphone
Fentanyl

A

Slide 30

98
Q

When treating pain, what are the goals of using opioid agonists?

A

To use short acting opioids
-At the lowest effective dose
-Used for just a few days
Slowly increase their dose as needed!

(Video 00:18)