provide leads in drug discovery. Quantum pharmacology calculations have been used to
designin silicolibraries of benzodiazepine analogs for use as potential building blocks
in the design of bioactive molecules.
Nevertheless, the GABAergic properties of benzodiazepines remain their most impor-
tant clinical application. Over the past 30 years, the most widely used benzodiazepine
drug has been diazepam (1.6). It is an anxiolytic, sedative, and muscle relaxant; the anx-
ious, depressed person becomes more outgoing and relaxed. There have been many
diazepam analogs. Oxazepam (4.177) and lorazepam (4.178) have similar effects.
Temazepam (4.179), flunitrazepam (4.180), and flurazepam (4.181) are useful sedative-
hypnotics. Clonazepam (4.182) is a clinically useful anticonvulsant. Brotizolam (4.183),
a novel benzodiazepine analog, seems to be an effective sedative-hypnotic. Midazolam
(4.184) is an imidazolo-benzodiazepine that is water soluble and thus easily injectable.
It is a hypnotic sedative with marked amnestic (i.e., memory loss) properties and is used
in dentistry, endoscopic procedures, and induction to anesthetics in the elderly and in
NEUROTRANSMITTERS AND THEIR RECEPTORS 275