Studies on the use of blood lithium concentrations in lithium therapy in Japan

The relationship between the concentration of lithium in whole blood and plasma was determined in 11 manic-depressive patients 12 h after the evening dose of lithium carbonate taken in the form of slow release tablets (Limas). Significant relationships were found between the concentration of lithium in whole blood and plasma as well as between the daily dose of lithium and the lithium concentration in whole blood and in plasma. The findings suggest that under certain conditions the concentration of lithium in a small sample of whole blood may be used to monitor lithium therapy in outpatients. The advantages of using whole blood are discussed.