Body fluid lithium measurements: severity of illness and prediction of outcome

The authors measured lithium ion in saliva and serum 24 hr after a loading dose of lithium, and recorded the amount of lithium excreted in the urine during the 24-hr test period. Their results support previous work indicating a correlation between serum and mixed saliva lithium levels. On a subsample of manic patients, no correlation could be found between lithium retention and clinical outcome, age of onset, or pretreatment severity of illness. In addition, they were unable to confirm a prior report that the 24-hr postloading dose serum lithium level was a predictor of eventual therapeutic dosage.