psychotropic drugs that have a calming effect. They reduce emotional tension, irritability, and anxiety, decrease the tonus of the skeletal musculature, influence a number of functions of the autonomic nervous system, and intensify the effect of some somnifacients.

In contrast to neuroleptics (major tranquilizers), tranquilizers do not cause retardation, excessive sleepiness, or neurological disturbances. Tranquilizers decrease the excitability of the limbic system, the thalamus, and the hypothalamus. Large doses suppress the activity of the reticular formation. The side effects of tranquilizers are insignificant, consisting mainly of muscular weakness. Tranquilizers do not have an antipsychotic effect, and are therefore used in psychiatry mainly to treat neuroses, psychopathies, and other borderline psychological states. They are also used to treat nervous diseases marked by increased muscle tonus, as well as some internal diseases.

Tranquilizers belong to various classes of chemical compounds. Most widely used are derivatives of benzodiazepine —chlordiazepoxide (Librium, Elenium), diazepam (Seduxen), oxazepam (Tazepam), and nitrazepam (Eunoctin, Radedorm). Derivatives of other chemical compounds used are meprobamate and trioxazine. The tendency toward excessive use of tranquilizers in many countries poses the problem of enacting measures to limit their use and to increase physicians’ control over their use. The enactment of such measures would serve to prevent widespread psychological dependence on tranquilizers.