SEDATIVE AND HYPNOTIC AGENTS
Section I. BACKGROUND
Sedative and hypnotic agents form an important class of drugs that are widely
used in modern medical practice. The names of many of the agents should be fairly
familiar to you since these drugs are so widely used in hospitals and dispensed to
patients on an outpatient basis. You probably know that most sedative-hypnotic agents
are controlled because of their abuse/misuse potential. The barbiturates have been
regarded as the prototypes of this class of drugs because of their extensive use over
the past 80 years. Because of their potential for addiction, physical dependence, and
side effects, the barbiturates have been replaced by the benzodiazepines (for example,
Valium). The benzodiazepines are currently the most important sedative hypnotics
because of their efficacy and safety.
7-2. DEFINITION OF SEDATIVE-HYPNOTIC
A sedative-hypnotic agent is a substance, which, if given in progressively larger
doses, produces calm (sedation), sleep (hypnosis), general anesthesia, and ultimately
death (because of medullary depression). Sedative-hypnotic agents are commonly
used for symptomatic relief of anxiety and for the induction of sleep. Sedatives may be
also referred to as anti-anxiety agents.
Section II. CLINICALLY IMPORTANT INFORMATION
Sedative-hypnotic agents are an important group of drugs, which are often
prescribed to a variety of patients. You should be familiar with the effects and the
clinical uses of these drugs.
7-4. THE PHARMACOLOGICAL ACTIONS OF SEDATIVE-HYPNOTIC AGENTS
a. Mechanism of Action. Sedatives and hypnotics selectively depress the
reticular activating system (RAS), the mechanism responsible for keeping us awake.