Flashcards in Pharm Quiz #8 Deck (126)
How are barbiturates classified(3)?
1. ultrashort barbiturates
2. short/medium-acting barbiturates
3. long-acting barbiturates
What are ultra-short acting barbiturates used for?
for anesthesia-short duration of action allows for emergence(Brevital)
What are short/medium-acting barbiturates used for?
for anesthesia purposes, anxiety and insomnia(mostly oral agents)
what are long-acting barbiturates used for?
for anticonvulsants, not for insomnia because of residual "hang-over" effect(phenobarbital).
What are barbiturates derived from?
What is a significant characteristics of all barbiturates?
all have long periods of "hand-over"
What percentage of barbiturate solution is used?
Available as 2.5% solutions only-5% solutions too caustic to vessels
Can barbiturates be mixed in the same line as opioids, catecholamines and neuromuscular blockers?
No....if given together they will react causing precipitation.
Are all barbiturates racemic mixtures?
Levorotary isomers of thiopental and thiamylal are ___ as potent as dextrorotary isomers.
twice as potent
Does barbituric acid have any CNS activity?
Substitution of which carbons determine drug characteristics?
#2 and #5
Characteristic of sulfuration.
greater lipid solubility
Characteristic of phenyl groups.
Characteristic of methyl group.
Are the sedative and anti-vonvulsant effects of barbiturates the same affect?
No they are separate effects
Prompt awakening from single dose barbs due to ___?
What inhibitory neurotransmitter does barbiturates interact with?
gamma-amino butyric acid(GABA) in CNS
How does barbs affect GABA receptors?
Barbs decrease GABA dissociation from receptors
In relation to barbiturates affect on GABA, what action does it create?
Causes increased duration of GABA activated openings of chloride ion channels.
What causes quick awakening from barbiturates?
How do barbiturates affect the reticular activating system? What is the reticular activating system?
Barbs depress the reticular activating system. The reticular activating system is the used to maintain wakefulness.
How do barbiturates contribute to lowered blood pressures?
Barbs depress SNS ganglia transmissions.
What does redistribution have to do with barbs?
Prompt awakening from single dose barbs due to redistribution.
The effect-site equilibration time for thiopental and methohexital is?
Rapid-time between dose and clinical effect is brief. Asleep in 15-20 seconds
Barbiturate complete elimination from the body depends upon?
Protein binding of barbs parallels?
Barbiturate lipid solubility is determined by solubility of the _____ molecule. Why?
Non-ionized molecule; Ionized barbiturate molecules are poorly lipid soluble
What is the greatest plasma bound barbiturate? How bound is it?
Thiopental; 72 - 86%