ABSTRACT
The barbiturates have been regarded as prototypes of the class because of their extensive use since their intro duction approximately 80 years ago. The motivation to develop other sedative-hypnotics can be attributed to efforts to avoid certain undesirable features of the bar biturates, including their potential for addiction and physical dependence. Unfortunately, such efforts have not always been successful. For example, the piperidinediones such as glutethimide, introduced as “nonbarbiturates,” are in fact chemically related and virtually indistinguishable from barbiturates in their pharmacologic properties (1). Because of the huge mar ket for sedative-hypnotics, such “failed attempts” have often been commercially successful. The propanediol carbamates such as meprobamate are of distinctive chemical structure but are practically equivalent to bar biturates in their pharmacologic effects, and their clini cal use is rapidly declining. The sedative-hypnotic class also includes compounds of simple chemical structure, including alcohols and the cyclic ethers. Chloral hydrate and its congeners, such as trichloroethanol, together with paraldehyde, continue to be used, particularly in institu tionalized patients. Several newer drugs that appear to be more successful in avoiding some of the adverse effects of the barbiturates have been introduced recently. Bus pirone is the first of these drugs to be approved for pre scription use.
