Tranquilizing drugs

Abstract

Dr. Richard J. Cross: The tranquilizing agents are not one but several groups of compounds which differ from each other widely but have been classified together. Some of them have very useful properties unrelated to the common label of “tranquilizer.” They all have undesirable side reactions, many of which result from their tranquilizing or other therapeutic properties. All of them do affect mood and alertness but not all in the same way or to the same degree. Our understanding of the mechanism of action of these drugs is far from clear and will probably require a greater comprehension of normal neurophysiology. Conversely, the research scientists seeking such a greater comprehension have found these new agents to be useful tools, and this, in the long run, may prove to be their most important contribution. Studies of the relationship between the metabolism of these compounds and that of serotonin, norepinephrine and psychotomimetic agents such as LSD are yielding interesting results which may represent the beginning of an understanding of their pharmacology and an opening for a new approach in neurophysiology. Chlorpromazine and related compounds have been found of great value in controlling vomiting, particularly when the Chemoceptive Emetic Trigger Zone is involved. Emesis due to motion sickness and gastric irritation is far more difficult to control. These compounds have shown a dramatic effect in suppressing the vertigo, nausea and vomiting of Meniere's syndrome. In other medical conditions the tranquilizing drugs have proved to be of great value, although their effects are somewhat less clear-cut. As their name implies, their chief usefulness has been in relieving tension and anxiety in actively functioning individuals. However, unless due caution is observed, this active functioning may be impaired. The management of hospitalized mental patients has undergone a major change since the introduction of these agents. Assaultive patients formerly handled only by restraint and isolation have now become amenable to treatment. The entire atmosphere of the mental institution has been altered. Outpatients are less amenable to such therapy, although in many these drugs have proved useful. As is usually the case when potent new drugs are discovered, the introduction of the tranquilizing agents has been followed by a great wave of enthusiasm and considerable overuse of these compounds. As objective, well controlled clinical studies have become available, we have gradually increased our understanding of both the usefulness and the dangers of these drugs. At the same time they are teaching us more about neuropharmacology which in due course will provide us with a clearer understanding of the mechanisms involved.