Fentanyl Flashcards
1
Q
What are the uses of fentanyl?
A
- periop analgesia
- obtunds hypertensive response to airway manipulation
- opioid based anaesthesia
- sedation by infusion
- chronic pain
2
Q
What is the MOA of fentanyl?
A
Potent agonist at MOP (mu) receptor
3
Q
What are the effects of fentanyl?
A
- same as morphine but:
- 50-80x more potent
- less histamine release
- decreases stress response to surgery
- associated with bradycardia
- chest wall rigidity in high doses
4
Q
What is the absorption/distribution of fentanyl?
A
- absorption orally from small intestine
- bioavailability 33%
- 80-95% protein bound
- vol of distribution - 0.88 - 4 L/kg
- short duration of action due to distribution
5
Q
What is fentanyl?
A
- synthetic opioid
- clear colourless solution 50mcg/ml
- patches/lozenges/PCTS (patient controlled transdermal system)
6
Q
What is the dose of fentanyl?
A
- for induction adjuct (1 - 100mcg / kg)
- pain relief - 1 mcg/kg + repeat to titrate to pain
- spinal 10-30 mcg
- epidural 25 - 100 mcg
7
Q
What are the chemical properties of fentanyl?
A
- pKa 8.4
- 9% unionized at pH 7.4
- highly ionized in stomach (99.9%)
- highly lipid soluble (600x more than morphine)
- syntehtic phenylpiperidine
8
Q
What is the pKa of fentanyl?
A
8.4
9
Q
What % of fentanyl is unionized at pH 7.4?
A
9%
10
Q
What % of fentanyl is plasma protein bound?
A
84%
11
Q
What is the relative lipid solubility of fentanyl?
A
580
12
Q
What is the terminal half life of fentanyl?
A
3.5
13
Q
What is the clearance of fentanyl?
A
10-15 ml/min/kg
14
Q
What is the volume of distribution of fentanyl?
A
3-5 L/kg
15
Q
What are the SEs of fentanyl?
A
- bradycardia
- hypotension
- PONV
- itch
- constipation
- resp depression
- urine retention
16
Q
What is fentanyl?
A
- synthetic opioid, takes 5 min for effect
- 100 times more potent than morphine
- analgesia lasts 15-30mins
17
Q
What is the does of fentanyl?
A
- 1-3 mcg/kg at induction
- 2-3 mcg/kg if tubing to decrease response to laryngoscopy
18
Q
What is fentanyl metabolised to?
A
Inactive products by the liver
