Serum concentration and clinical supervision in monitoring of lithium treatment.

Lithium therapy has become generally accepted as one of the major regimens for the treatment of acute mania as well as for the prevention of relapse in recurrent bipolar mood disorders. It is one drug for which monitoring is understood to be crucial, since the drug (1) has broad interindividual variability in dose-response, (2) often has a very narrow intraindividual therapeutic concentration index, (3) has a broad interindividual distribution of sensitivity and tolerance, and (4) is extremely dependent on stable kidney function for its successful and safe use. Determination of serum lithium concentration is the most important monitoring technique. However, the need for standardized clinical procedure coupled with corresponding reference ranges remains to be satisfied. The 12 hr standardized serum lithium is seen as the answer to this need, and the specifics of and indications for the procedure and appropriate reference values are given. The therapeutic range is suggested to lie between 0.30 and 1.30 mmoles/liter, with 1.50 mmoles/liter representing the lower limit of risk for intoxication. The treatment of initial and intercurrent lithium intoxication, which can reach life-threatening proportions, is also described.