one of a chemically heterogeneous group of medicinal substances of vegetable and synthetic origin that exert a calmative effect. In the narrow sense of the word, a sedative is a substance that produces only a calmative effect; this type includes valerian, motherwort, menthol, and bromides of sodium and potassium. Tranquilizers that dispel anxiety are known as anxiolytic sedatives; these tranquilizers include derivatives of propanediol (for example, meprotan), diphenylmethane (for example, actozine), benzodiazepin (for example, diazepam), and trioxazine. Also used as sedatives are somnifacients, including phenobarbital, which are used in small doses, and neuroleptics, for example, aminazine and Tisercin. Combined neuroleptics are also used, for example, Bekhterev’s mixture (sodium bromide and an infusion of adonis and codeine phosphate), Corvalol (ethyl ester of α-bromoisovaleric acid, phenobarbital sodium, mint oil, ethyl alcohol, and water), and Validol (a solution of menthol in menthyl ester of isovaleric acid).
Sedatives produce a calmative effect and decrease feelings of fear, anxiety, and mental tension without substantially interfering with attentiveness and mental and physical efficiency. They can therefore be used during the day. In therapeutic doses they are not themselves somnifacient but may promote the normalization of disrupted sleep. The mechanism of the action of sedatives is not completely clear. It is conjectured that sedatives are capable of selectively suppressing the subcortical (limbic) and cortical structures of the brain that regulate emotions.
Sedatives are used widely in modern medical practice. Surgically and anesthesiologically they are administered particularly during preoperative and postoperative procedures. They are used in treating such internal diseases as hypertension and myocardial infarction. Sedatives, however, have been and are used primarily in neuropathology and psychiatry in treating neuroses and other borderline mental diseases accompanied by obsessions, fear, and agitated depression (sometimes sedatives are combined with neuroleptics or antidepressants). Treatment is prolonged. Both the selection of a preparation and the appropriate individual dosage are important. Sedatives are usually tolerated well, and the side effects are insignificant. Sleepiness or lethargy may result from an overdose. Sedatives do not usually produce cumulation, habituation, or predilection,
K. S. RAEVSKII