sedative-hypnotic, a drug that reversibly depresses the activity of the central nervous system, used chiefly to induce sleep and to allay anxiety. Barbiturates, benzodiazepines, and other sedative-hypnotics have diverse chemical and pharmacological properties that share the ability to depress the activity of all excitable tissue, especially the arousal center in the brainstem. Sedative-hypnotics are used in the treatment of insomnia, acute convulsive conditions, and anxiety states and in facilitation of the induction of anesthesia. Although sedative-hypnotics have a soporific effect, they may interfere with rapid eye movement sleep associated with dreaming and, when administered to patients with fever, may act paradoxically and cause excitement rather than relaxation. Sedative-hypnotics may interfere with temperature regulation, depress oxygen consumption in various tissues, and produce nausea and skin rashes. In elderly patients they may cause dizziness, confusion, and ataxia. Drugs in this group have a high potential for abuse that often results in physical and psychological dependence. Treatment of dependence involves gradual reduction of the dosage because abrupt withdrawal frequently causes serious disorders, including convulsions. Acute reactions to an overdose of a sedative-hypnotic may be treated with an emetic, activated charcoal, gastric lavage, and measures to maintain airway patency. Buspirone, zolpidem, and zaleplon are among the newer nonbarbiturate-nonbenzodiazepine sedative-hypnotic drugs. See also barbiturate, benzodiazepine derivative.
