The use of rubidium chloride in depressive disorders: clinical aspects

Abstract

Rubidium, discovered in 1861, by Bunsen and Kirchoff, is one of the Group 1 A alkali metals belonging to the same periodic series as lithium, sodium, potassium and cesium. It is widely distributed in mineral deposits and can be extracted from lepiodolite and carnallite rocks, wich are also the major sources of lithium. Rubidium is also present in virtually all biological systems. Physiologically, rubidium most resembles potassium, and these two elements have a great decree of metabolic interchange-ability. Meltzer and his group (1) early reported that rubidium increased the prevalent frequency of the EEG in monkeys and altered the behavior in the direction of increased activity. So it has been hypothesize d that rubidium, like lithium, might therefore have application in psycho pharmacology, particularly in the affective disorders. Moreover Stolk et al.(2) suggested that rubidium enhanced the turnover of norepinephrine in rats whose biosynthesis of norepinephrine was inhibited. Further observation of Stolk et al.(3) demonstred that rubidium increased normeta nephrine formation in rat brain, an effect opposite to that seen with li thium. In 1971 Fieve et al.(4) reported initial experience on RbCl ingestion by volunteers subjects:in that time the rediscovery of rubidiu m was started. As lithium appears to be a specific “replacement-like” therapy for mania, so it has been hypothesized that rubidium might offer the same chance for one or more depressive disorders (5). In the last 10 years very few clinical experiences about rubidium effects are available in literature(6). Four manic-depressive patients were treated with rubidium chloride therapy;two patients had a prolonged manic phase(7). The purpose of this study is the assesment of the therapeutic effect of rubidium in depressive patients in correlation with the plasma level of this substance and the monitoring of side effects.