Propofol Flashcards
BONUS
Which of the following is the chemical structure of propofol (Diprivan)?
Drug B is 2,6 diisopropylphenol - AKA Propofol
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
What is the pharmacologic category/class of propofol?
- General Anesthetic - Hypnotic
- Alkylphenol
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
What is the mechanism of action of propofol?
Direct GABAA receptor agonist and potentiates actions of endogenous GABA → ⇑ Cl- conductance → neuronal hyperpolarization
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
Nagelhout (7th ed.), p. 103
What is the adult dosing of propofol for induction?
What is the pediatric dosing of propofol for induction?
- 2-3 mg/kg
This is related to a larger volume of distribution
What is the dosing range of propofol for continuous infusion (sedation, TIVA)?
What is the onset of action for propofol?
- Immediate - 9-51 seconds (avg. 30 seconds)
- “Textbook” answer is 30-60 seconds
Dose dependent and influenced by patient specific circulation time
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
What is the duration of action for propofol?
- 3-20 minutes — awakening is related to redistribution from brain
Duration may be dependent on dose, rate, and duration of administration - it is also influenced by patient specific circulation time/redistribution
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
What organ(s) are responsible for propofol’s clearance (metabolism/elimination)?
- Metabolism: Liver (P450), with extrahepatic metabolism in lungs likely
- Elimination: Kidneys
Half-life: ~0.5-1.5 hours
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
True or False
Egg allergy is an absolute contraindication to propofol use
False
- while propofol formulations include lecithin derived from egg yolks, there is no good evidence that it should be avoided in patients allergic to egg (or soy/peanut)
In fact, Europe does not even include this in manufacturing information!
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 2. Propofol: Part 2
Because propofol is emulsified in soy and/or egg fats, bacterial growth is possible - spiked vials, and prepared syringes must be discarded within what time frame?
- 6 hours if the drug has been removed from the vial
- 12 hours if the drug remains in the vial (after rubber stopper has been punctured - i.e. during infusion)
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 2. Propofol: Part 2
Cardiovascular effects of propofol include:
- Decreased SVR & BP (due to ↓ SNS tone, vasodilation)
- Decreased venous tone → decreased preload
- Decreased CO (due to myocardial depression/↓ myocardial contractility)
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
What are the respiratory effects of propofol?
- Dose dependent depression of ventilation
(shifting of the CO2 response curve) - Apnea following initial administration/induction
- Inhibits hypoxic ventilatory drive
- Bronchodilation
Anesthesia Guidebook - Episode 17: Anesthesia Top Drawer Run Down - Part 1
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
Nagelhout (7th ed.), p. 104
What effect does propofol have on the CNS (e.g. CMRO2, cerebral blood flow, ICP)
- ↓ CMRO2, ↓ CBF (maintains coupling)
- ↓ ICP
Some say myoclonus is possible, but much less common than etomidate
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
BONUS
Propofol infusions can change the color of the urine
- green urine = _________ excretion
- _______ urine = increased uric acid excretion (does not suggest renal impairment or infection)
- phenol
- cloudy
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 1. Propofol: Part 1
The following preservatives may be used in different generic formulations of propofol - which patient populations should they warrant precaution in?
- Benzyl alcohol
- Sodium metabisulfite
- Avoid in infants (neurotoxicity)
- Use with caution in patients with allergies and asthma (may cause bronchospasm)
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 2. Propofol: Part 2
Nagelhout (7th ed.), p. 102 - Table 9.1
Propofol may cause pain or burning on injection - how can this be eliminated or minimized?
- Use of a larger and more proximal vein
- Giving an opioid or lidocaine prior to administration
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 2. Propofol: Part 2
Propofol has antipruritic effects and can reduce itching caused by spinal opioids and cholestasis - what is the appropriate dose for this indication?
- 10 mg IV
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 2. Propofol: Part 2
Propofol has antiemetic effects and can be used to treat PONV - what is the appropriate dose for this indication?
- 10-20 mg IV
- Infusion of 10 mcg/kg/min can also be used
Apex Unit 4: Pharmacology 1; Intravenous Anesthetics; Lesson 2. Propofol: Part 2
What is the concentration (mg/mL) of propofol vials?
