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24 Cards in this Set
- Front
- Back
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Define stereoisomers.
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Stereoisomers: are isomeric molecules that have the same molecular formula and sequence of bonded atoms (constitution), but which differ only in the three-dimensional orientations of their atoms in space
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Define enantiomers.
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Enantiomers: are two stereoisomers that are related to each other by a reflection: they are mirror images of each other, which are non-superimposable
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What is an intravenous anaesthetic agent?
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Intravenous anaesthestics: are agents that will induce loss of consciousness in one arm-brain circulation time.
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What are the 2 major classes of intravenous anaesthetics?
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1- barbiturates (thiopental, methohexitone)
2-Non-barbiturates (propofol, ketamine, etomidate) |
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What is the structure of a phenol?
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structure is that of a hydroxyl group (-OH) bonded to a phenyl ring, making it an aromatic compound
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What is a phosphatide?
Why is it important? |
phosphatidic acid or any of its esters. Phosphatidic acid (diacylgycerol phosphate) consists of glycerol esterified to phosphoric acid and to two fatty acids. Phosphatides are major components of cell membrane
it is important because egg phosphatide is used in the lipid-water emulsion used for presentation of propofol |
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What is an emulsion?
Why is it important? |
An emulsion is a mixture of two or more immiscible (unblendable) liquids by the facilitation of an emulsifier
propofol is presented as an emulsion. |
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What is the pKa for propofol?
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11
Thus mainly in the unionised form in the body's pH of 7.4 |
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What is a racemic mixture?
Importance? |
a racemic mixture, is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule
Ketamine is presented as a racemic mixture |
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What are the targets of action for the IV anaesthetic agents?
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GABA a receptors and NMDA receptors
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Which subunit in the GABA a receptor does propofol and etomidate work on?
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the β subunit
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What is burst suppression?
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High-voltage bursts of slow, sharp, and spiking activity alternating with a suppressed background have been termed burst suppression
Usually associated with severe encephalopathy, but can be caused by high doses of propofol |
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What is a 'sedative'?
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a calming, quieting agent
an agent that quiets nervous excitment |
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What is a 'hypnotic' agent?
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an agent which promots sleep
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Describe the abnormal movements that can happen with propofol induction.
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They represent an imbalance in the subcortical excitatory-inhibitory center:-
1- dystonic movements: abnormal tonicity in the muscles or spasms 2- Choreiform movements:Irregular, spasmodic, involuntary movements of the limbs or facial muscles, often accompanied by hypotonia. The location of the responsible cerebral lesion is not known. 3- Opisthotonos: A tetanic spasm in which the spine and extremities are bent with convexity forward, the body resting on the head and the heels |
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What is propofol infusion syndrome?
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Refractory bradycardia leading to asystole in the presence of one or more of:
-metabolic acidosis -rhabdomyolysis -hyperlipidemia -enlarged or fatty liver Infusions of propofol >48 hrs at 4 mg/kg/hr |
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What is e?
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the base of the natural logarith
=2.718 |
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What does inotropic and metatropic mean?
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inotropic: linked to an ion channel
metatropic: linked to a G-protein |
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What is a chiral molecule?
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A chiral molecule is a type of molecule that lacks an internal plane of symmetry and has a non-superimposable mirror image
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What does dextrorotary molecule mean?
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it is the (+) enantiomer
meaning in a solution, it would rotate polarized light in a clockwise direction |
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Levoratory?
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(-)
would rotate light in a counter-clockwise direction |
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Describe the R/S system for classifying enantiomers.
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It labels each chiral center R or S according to a system by which its substituents are each assigned a priority, according to the Cahn Ingold Prelog priority rules (CIP), based on atomic number. If the center is oriented so that the lowest-priority of the four is pointed away from a viewer, the viewer will then see two possibilities: If the priority of the remaining three substituents decreases in clockwise direction, it is labeled R (for Rectus), if it decreases in counterclockwise direction, it is S (for Sinister).
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What is context-sensitive half-llife?
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refers to the time it takes for the plasma concentration to fall by half after cessation of continuous infusion
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What is arm-brain circulation time?
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the time it takes for the drug to travel from the injection site to the brain, which is referred to as one "arm-brain circulation time" and requires less than one minute
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