Opioid agonists pt 2 (Ex2)

Question 1

How potent is fentanyl?

Answer 1

• 75 - 125 x morphine.

Question 2

What is the blood-brain equilibration of fentanyl?
What does this mean?

Answer 2

• 6.4 minutes
• Potent with rapid onset and ↑ lipid solubility.

Question 3

What percent of fentanyl is subject to lung first-pass effect?
What does this mean?

Answer 3

• 75%
• Drug is taken up into lung tissue and possibly subjected to breakdown via pulmonary esterases.

Question 4

Where is fentanyl metabolized?
What is its principal metabolite?

Answer 4

• Liver via CYP3A
• Norfentanil

Question 5

How does fentanyl dosing change for the elderly or liver cirrhosis?

Answer 5

No change in elderly or cirrhotic patients.

Question 6

Describe what the graph below is showing.

Answer 6

Fentanyl has the greatest context-sensitive half-time of any of the fentanyl derivatives.

Question 7

What is the analgesia dosage of fentanyl?
Induction dose?

Answer 7

• Analgesia: 1 - 2 μg/kg IV
• Induction: 1.5 - 3 μg/kg IV

Question 8

1mg of PO fentanyl = ____ mg of IV morphine

Answer 8

5

Question 9

What is the intrathecal dosage of fentanyl?

Answer 9

25 mcg

Question 10

What is the adult oral dose of fentanyl?
Pediatric?

Answer 10

• Adult: 5 - 20 mcg/kg
• Peds: 15 - 20 mcg/kg

Question 11

What is the transdermal dose of fentanyl?

Answer 11

• 75 - 100 μg (18 hours steady delivery)

Question 12

What cardiovascular side effects should be known about fentanyl?
What CNS side effects should be known?

Answer 12

• ↓BP & ↓CO
• Can cause seizures & modestly increase ICP.

Question 13

How much more potent is sufentanil than fentanyl?

Answer 13

• 5-12 times more potent.

Question 14

How much of sufentanil is subject to first pass effects?

Answer 14

• 60% lung first-pass

Question 15

How much of sufentanil is protein bound? What protein is it bound to?

Answer 15

92.5% α-1 acid glycoprotein bound.

Question 16

What is the analgesia dose of sufentanil?

Answer 16

• Analgesia: 0.1 - 0.4 μg/kg IV

Question 17

What is the induction dose of sufentanil?

Answer 17

18.9 mcg/kg IV

Question 18

What is the potency of alfentanil?
What is its onset?

Answer 18

• 20% as potent as fentanyl
• Onset: 1.4 min (faster than all derivatives except remifentanil)

Question 19

What is the alfentanil induction dose?
What about laryngoscopy dose?
What about maintenance?

Answer 19

• Induction: 150 - 300 μg/kg IV
• Laryngoscopy: 15 - 30 μg/kg IV
• Maintenance: 25 - 150 μg/kg/hr IV with inhaled anesthetics

Question 20

What drug can cause acute dystonia when given to a Parkinson’s patient?

Answer 20

Alfentanil

Question 21

What receptor affinity does remifentanil have?
How potent is it?

Answer 21

selective μ opioid agonist
same potency as fentanyl

Question 22

What is remifentanil’s structure and why is it important?

Answer 22

Ester Structure = hydrolyzed by plasma & tissue esterases.

• Rapid onset & offset
• Very titratable
• No accumulation

Question 23

Answer the following characteristics of remifentanil below:
Clearance:
Peak effect:

Answer 23

• Clearance: 3-4L/min (8x faster than alfentanil)
• Peak: 30-60 seconds (fastest fentanyl derivative)

Question 24

What is the induction dose of remifentanil?

Answer 24

• 1 μg/kg IV over 1 min

Question 25

What is the maintenance dosing of remifentanil?

Answer 25

- 0.005 - 2 μg/kg/min IV

Question 26

How potent is hydromorphone? What dose should be given? What benefits does hydromorphone have over morphine?

Answer 26

- 5x more potent than morphine - 0.5mg IV → 1-4 mg total - **No histamine release & no active metabolites.**

Question 27

Why is codeine not given IV?

Answer 27

- Induced hypotension via histamine release.

Question 28

What is the dose of codeine for cough suppression? Analgesia?

Answer 28

- Cough: 15mg - Analgesia: 60mg (= about 5mg morphine)

Question 29

Which opioid is most cleared?

Answer 29

- Remifentanil (3-4L/min)

Question 30

Which opioid(s) is/are the most protein bound? Which is the least?

Answer 30

- Sufentanil, alfentanil, & remifentanil - Least = morphine

Question 31

Which opioid is the highest percent non-ionized?

Answer 31

- Alfentanil

Question 32

Morphine tends to relieve _____ type pain more than _____ type pain.

Answer 32

Dull: sharp

Question 33

Opioid + N2O or benzos can lead to?

Answer 33

CV depression (CO & BP)

Question 34

What negative effect does post-op shivering have?

Answer 34

increased metabolic demand 500%

Question 35

What is the sufentanil intraop dose? What is the infusion dose?

Answer 35

intraop: 0.3 - 1μg/kg IV infusion: 0.5 - 1μg/kg/hr IV

Question 36

What is the metabolism profile for alfentanil? (metabolized by and metabolite)

Answer 36

metabolized by hepatic p450 metabolite: noralfentanil

Question 37

What is the E1/2 time of remifentanil?

Answer 37

6.3 minutes

Question 38

How potent is tramadol?

Answer 38

5-10x **less** than morphine