Anxiolytics and Hypnotics Flashcards
What is tranquilization?
the patient is relaxed, unconcerned with his or her surorundings and is FULLY FUNCTIONAL
What does a sedative do?
decreases activity, moderates excitement and calms patient although PATIENT IS AWAKE
What does a hypnotic do?
produces drowsiness and facilitates the onset and maintenance of sleep, but patient may be EASILY AROUSED
How are hypnotics different from general anesthetics?
when a patient is under general anesthetics they can’t be aroused
What are barbiturates classified?
their mechanism of action is all the same, so they’re classified by their duration of action:
ultra-short acting
short-intermediate acting
long acting
What are the characteristics of ultra-short acting barbiturates?
(i.e. why are they so fast acting, how is function terminated)
their half life is only minutes because they’re very lipid soluble
they reach the CNS very quickly
termination of action is thorugh redistribution to muscle and other sites
What are two examples of ultra-short acting barbiturates?
thiopental (pentothal)
methohexital (brevital)
How long is the half life for the short-intermediate acting barbiturates? What does it depend on?
half-life is hours
depends on rate of metabolism
What is an example of a short-intermediate acting barbiturate?
secobarbital (seconal)
What is the half life for the long acting barbiturates? How?
days
very slow metabolism - can be excreted wholly or partially unchanged
What is an example of a long acting barbiruate?
phenobarbital
What tissues do barbiturates cause depression in?
produces reversible depression of ALL excitable tissue (nervous, smooth muscle, cardiac muscle)
CNS most sensitive
What barbiturate is selectively anticonvulsant, while the remainder are relatively unselective in their depression of the CNS?
phenobarbital
What are barbiturates affect on pain?
pain is the one function which is not impaired until unconsciousness
in fact, at small doses you have hyperalgesia!
What effects of barbiturates will develop tolerance and which won’t>
tolerance developes for: mood, sedation and hypnosis
Not to anticonvulsant and lethal effects
With repeated use of a barbiturate, there is a ____ in the drug’s therapeutic index.
Why is this really important public health-wise?
decrease
this is important because barbiturate shave the highest rate of accidental OD among drug abusers because of it.
What is the mechanism of the barbiturates?
it facilitates GABA- mediated neuronal hyperpolarization by Cl- inflow
specifically, they increase the duration the Cl- channels are open
it potentiates GABA’s inhibitory effect on CNS function