What receptor does barbiturates, benzos, and propofol target?
GABA-A receptors
How do you approach patients who are allergic to egg and need propofol?
Most patients are allergic to egg albumin (egg whites) and not egg lecithin (yolk - what propofol is used in)
What does it mean to be a more potent drug? A more efficacious drug?
More potent: same effect achieved by a lower dose
More efficacious: same dose gives a lesser effect
Blood is sampled from the hepatic vein. Which would have the lowest concentration compared to central blood: propofol, fentanyl, midazolam, etomidate, esmolol
Propofol: completely metabolized by the liver on a single pass
Midazolam, fentanyl and etomidate are only partially metabolized on a single pass
Esmolol is metabolized by RBC esterases
A drug is highly protein bound but the patient has low levels of protein. Compared to normal protein levels, the drug would be: less efficacious, more potent, higher ED50, cleared slowly
More potent (more in the free/active form)
ED50: dose at which 50% of patients respond - this would decrease in this case (lower dose for the same response)
Which of the following does not work through a G-protein coupled receptor: Fentanyl, midazolam, epinephrine, serotonin, histamine
Midazolam (GABA-A which is a ligand-gated ion channel); the rest work through GPCR (through cAMP or IP3)
What is the largest extrahepatic site of metabolism for propofol?
The lungs
How is fospropofol different from propofol?
Prodrug of propofol that needs to get metabolized in the liver to become propofol and formaldehyde; thus it has a slower onset of action
Which of the following does not have an active metabolite: midazolam, propofol, meperidine, ketamine, morphine
Propofol
Midazolam -> alpha-1-hydroxymidazolam
Meperidine -> normeperidine (CNS excitation in renal failure)
Ketamine -> norketamine
Morphine -> M6G
