The benzodiazepines were introduced into clinical practice in the 1960s for the treatment of anxiety and sleep disorders. Members of this class of drug were classified initially as minor tranquilizers although this term has fallen into disfavor. These agents have proven to be safe and effective alternatives to older SEDATIVE-HYPNOTIC agents such as BARBITURATES, CHLORAL HYDRATE, glutethimide, and carbamates. Benzodiazepines are widely prescribed drugs, with 8.3 percent of the U.S. population reporting medical use of these agents in 1990.

Basic Pharmacology

All benzodiazepines produce similar pharmacologic effects, although the potency for each effect may vary with individual agents. They decrease or abolish ANXIETY, produce sedation, induce and maintain sleep, control certain types of seizures, and relax skeletal muscles. The basic chemical structure is shown in Figure 1.

Dissimilarity in the effects of different benzodiazepines tend to be more quantitative than qualitative in nature. Many of these differences are attributable to...