Pharmacokinetics and Benzodiazepines: Introduction and
Benzodiazepines have a prominent role in
anesthesia that only because of their amnestic effects but also
because of their anxiolytic actions.
They frequently prescribed benzodiazepine,
diazepam (Valium), was introduced over 40 years ago, whereas the
more water-soluble midazolam (Versed) product has been available
for about 25 years. Midazolam (Versed) exhibits excellent
anxiolytic and anterograde amnestic properties.
Benzodiazepines affect GABA-mediated
systems. The neurotransmitter GABA is an inhibitory
neurotransmitter and controls the state of a chloride ion
channel. Activation of this chloride ion channel results in
neuronal hyperpolarization (increased membrane potential in the
direction away from the threshold potential) and accounts for the
classification of the GABA system as "inhibitory".
Benzodiazepines increase the inhibitory action at the GABA
Midazolam (Versed) exhibits significant lipid
solubility, following injection, because the previously open
imidazole ring closes at physiological pH (7.4).
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