Chapter 12: Propofol
Which of the following is NOT a direct central nervous system effect of propofol?
(A) GABAA receptor activation in the hippocampus
(B) widespread NMDA glutamate receptor inhibition
(C) decreased serotonin levels in the area postrema
(D) activation of glycine-gated chloride channels in the spinal cord
(E) activation of α2 adrenergic receptors in the locus ceruleus
The answer is E. Dexmedetomidine is an agonist of α2 adrenergic receptors. Activation of these receptors in the locus ceruleus results in sedation. Alpha2 adrenergic receptors may have an indirect role in propofol's sedative effects.
Propofol has many CNS effects including:
GABAA receptor activation in the hippocampus, which is a probable site of propofol's amnestic effects
Widespread NMDA glutamate receptor inhibition
Decreased serotonin levels in the area postrema, an action mediated by GABA receptor activation, which may mediate the antiemetic effects of propofol
Activation of glycine-gated chloride channels in the spinal cord.
Ref: Miller RD. Miller's Anesthesia. 8th ed. Philadelphia, PA: Elsevier; 2015.
Fospropofol is a prodrug that is converted to propofol by:
(A) hydrolysis by alkaline phosphatases
(B) hydrolysis by blood and tissue esterases
(C) hydrolysis by butyrylcholinesterases
(D) a Hofmann elimination reaction
(E) intramolecular rearrangement at physiologic pH
The answer is A. Fospropofol is converted to propofol by hydrolysis by endothelial cell surface alkaline phosphatases.
Remifentanil is hydrolyzed by blood and tissue esterases.
Succinylcholine is hydrolyzed by butyrylcholinesterases.
Atracurium and cis-atracurium are metabolized via a Hofmann elimination reaction.
Midazolam undergoes intramolecular rearrangement at physiologic pH.
Ref: Brunton LL, Chabner BA, Knollman BC. Goodman & Gilman's the Pharmacological Basis of Therapeutics. 12th ed. New York, NY: McGraw Hill; 2011.
The pharmacokinetics and pharmacodynamics of propofol are altered by age. Based on a mg/kg dose, which of the following patients requires the largest induction dose of propofol?
The answer is B. The induction dose of propofol for children younger ...