Propofol Flashcards
What is the dose of propofol?
1-2mg/kg
What is the onset and offset time of Propofol?
Onset~30secs (dependant on CVS)
Offset~3-7mins
Describe the effects of Propofol on the different systems?
CNS: hypnosis
CVS: Reduced SV, possible slight reduced HR, Reduced MAP
RS: depression of laryngeal reflexes, dose dependent respiratory depression
GI: antiemetic effects
Metabolic: metabolic infusion syndrome with long term infusions, more common in children
How common are hypersensitivity reactions?
1 in 100,000
What chemical class does propofol belong to and what physicochemical properties does it have?
It is a phenol
Has a pKa of 11, so exists almost entirely in the unionized, i.e. more lipid-soluble, form. It is extremely lipid soluble.
About 98% is bound to plasma proteins. (Note it is the non protein bound portion which is active)
Why is propofol stored as an emulsion and what is it stored with?
It is stored as an emulsion as it is extremely lipid soluble therefore not water soluble.
A lipid emulsion of propofol together with an emulsifying agent, i.e. egg phosphatide, and glycerol.
What is the chemical name of propofol, and draw the structure?
2,6-diisopropylphenol
When the plasma concentration of propofol drops what processes are occurring?
Redistribution to different compartments. Redistribution is dependant on blood flow, i.e drugs will be redistributed to muscle (well perfused) more rapidly than adipose (poorly perfused)
Metabolism.
Where is propofol metabolised?
It is metabolised in the liver.
Note it has no active metabolites.
